• Rules FAQ

    From SP@21:1/5 to All on Thu Sep 21 12:27:54 2017
    luis.9.8.87@gmail.com hat am 21.09.2017 um 11:39 geschrieben:
    I don't understand why this has to be published every month. Anyone interested can find it by looking up "FAQ".


    Why? Because it is quite often the only posting in a month. ;-)

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  • From =?UTF-8?Q?Luis_Bola=C3=B1os_Mures?=@21:1/5 to All on Thu Sep 21 10:03:21 2017
    El jueves, 21 de septiembre de 2017, 12:27:56 (UTC+2), SP escribió:
    luis.9.8.87@gmail.com hat am 21.09.2017 um 11:39 geschrieben:
    I don't understand why this has to be published every month. Anyone interested can find it by looking up "FAQ".


    Why? Because it is quite often the only posting in a month. ;-)

    That would be another reason not to post it, I think. If it's already the latest and hence most visible thread, why making a duplicate?

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  • From =?UTF-8?Q?Luis_Bola=C3=B1os_Mures?=@21:1/5 to All on Thu Sep 21 10:10:01 2017
    That would be another reason not to post it again, I think. If it's already the latest and most visible thread, why creating a duplicate?

    --- SoupGate-Win32 v1.05
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  • From Bill@21:1/5 to luis.9.8.87@gmail.com on Thu Sep 21 14:00:25 2017
    luis.9.8.87@gmail.com wrote:
    I don't understand why this has to be published every month. Anyone interested can find it by looking up "FAQ".

    I agree that it's irritating to see "a piece of crap" posted to the
    newsgroup every month. Any effort spent revising it would be better appreciated.

    --- SoupGate-Win32 v1.05
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  • From =?UTF-8?Q?Luis_Bola=C3=B1os_Mures?=@21:1/5 to All on Fri Sep 22 00:38:45 2017
    El jueves, 21 de septiembre de 2017, 20:00:58 (UTC+2), Bill escribió:
    luis wrote:
    I don't understand why this has to be published every month. Anyone interested can find it by looking up "FAQ".

    I agree that it's irritating to see "a piece of crap" posted to the newsgroup every month. Any effort spent revising it would be better appreciated.

    What's so bad about it?

    --- SoupGate-Win32 v1.05
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  • From Robert Jasiek@21:1/5 to luis.9.8.87@gmail.com on Tue Sep 26 06:18:24 2017
    luis.9.8.87@gmail.com wrote:
    I don't understand why this has to be published every month.

    Nothing "has to" be published every month. It is sufficient that there
    is a reason for some.

    For those who can learn information useful for them from reading it
    here, the reason is to provide this possibility frequently enough.

    Less frequently than monthly is not frequently enough, as rules
    requests by newbies have shown. People consulting RGG to get
    information expect information here so additional places of
    information do not replace this place of information.

    Obviously, people already knowing the Rules FAQ well do not need to
    read it. The posting is not for those not wanting to read it but is
    for those wanting to read it. Surprise.

    If anybody feels annoyed by a recurring post, use your usenet reader's
    message filters.

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  • From Robert Jasiek@21:1/5 to Bill on Tue Sep 26 06:25:53 2017
    Bill wrote:
    "a piece of crap"

    Insulting comments convince nobody.

    Not using the full name makes it hard to impossible to associate
    current opinion with earlier opinion stated by somebody using the same
    first name because one cannot know for sure which messages belong to
    which person.

    --- SoupGate-Win32 v1.05
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  • From S. Jasiek@21:1/5 to S. Jakiek on Wed Sep 27 00:54:28 2017
    Sorry, I misspelled my name in the "from" field.



    S. Jakiek wrote:
    Robert Jasiek wrote:
    Bill wrote:
    "a piece of crap"
    Insulting comments convince nobody.

    I don't think it was intended to be insulting (who did it insult?). It appeared to more of an editorial comment. Anyone who is curious can
    find the basis for the comment in earlier posts.

    Not using the full name makes it hard to impossible to associate
    current opinion with earlier opinion stated by somebody using the same
    first name because one cannot know for sure which messages belong to
    which person.

    Just because someone uses a particular name, you'll never know for
    sure the source of a message.

    Sam Jasiek



    --- SoupGate-Win32 v1.05
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  • From S. Jakiek@21:1/5 to Robert Jasiek on Wed Sep 27 00:47:56 2017
    Robert Jasiek wrote:
    Bill wrote:
    "a piece of crap"
    Insulting comments convince nobody.

    I don't think it was intended to be insulting (who did it insult?). It
    appeared to more of an editorial comment. Anyone who is curious can find
    the basis for the comment in earlier posts.

    Not using the full name makes it hard to impossible to associate
    current opinion with earlier opinion stated by somebody using the same
    first name because one cannot know for sure which messages belong to
    which person.

    Just because someone uses a particular name, you'll never know for sure
    the source of a message.

    Sam Jasiek

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From S. Jasiek@21:1/5 to S. Jasiek on Wed Sep 27 01:09:54 2017
    A apologize for the misspelling in my previous message.

    S. Jasiek wrote:
    Robert Jasiek wrote:
    Bill wrote:
    "a piece of crap"
    Insulting comments convince nobody.

    I don't think it was intended to be insulting (who did it insult?). It appeared to more of an editorial comment. Anyone who is curious can
    find the basis for the comment in earlier posts.

    Not using the full name makes it hard to impossible to associate
    current opinion with earlier opinion stated by somebody using the same
    first name because one cannot know for sure which messages belong to
    which person.

    Just because someone uses a particular name, you'll never know for
    sure the source of a message.

    Sam Jasiek



    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Bill@21:1/5 to S. Jasiek on Fri Sep 29 02:42:20 2017
    S. Jasiek wrote:
    Robert Jasiek wrote:
    Bill wrote:
    "a piece of crap"
    Insulting comments convince nobody.

    I don't think it was intended to be insulting (who did it insult?). It appeared to more of an editorial comment. Anyone who is curious can
    find the basis for the comment in earlier posts.

    You are completely correct, Sam. Thanks!
    Bill

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Robert Jasiek@21:1/5 to All on Thu Oct 12 10:40:55 2017
    Title: Rules FAQ
    Author: Robert Jasiek <jasiek@snafu.de>
    Frequency: monthly
    Last Update: 2016-02-12; First Day: 1999-04-12
    Distribution: rec.games.go
    Copyright: free non-commercial usage for promotion

    0 CONTENTS

    1 Purpose of this Paper
    2 Information for Beginners
    3 Important Concepts
    4 Particular Rules
    5 Troublesome Details
    6 Tournament Rules
    7 Links

    1 PURPOSE OF THIS PAPER

    This paper is a basic reference for important rules terms,
    rules, and tournament rules. Beginners should read
    especially chapters 2 and 3, players chapters 3 to 5,
    tournament players and organizers chapter 6.

    2 INFORMATION FOR BEGINNERS
    2.1 What Must I Know as a Beginner?

    The game is played on a grid board. Typically it has 19x19
    intersections, but 9x9 are also fine. Two players compete.
    The first player uses black stones, the other white.

    The players alternate. A player may play or pass. Playing
    is putting one's own stone on an empty intersection and
    removing any surrounded opposing stones. To avoid
    cycles, a play may not recreate any prior configuration of
    all stones on the board.

    Two successive passes end the game. Then the player with
    more intersections wins. Intersections are his if only his
    stones occupy or surround them.

    2.2 Which Rules do I Need as a Beginner?

    You can play with short rules as in 2.1. Other rules may
    be different, but the game is the same, i. e. strategy,
    tactics, and the score do not change. Extremely rare
    exceptions confirm this rule.

    The winner can be determined by area or by territory.
    Either includes empty intersections surrounded only by own
    stones. While area adds intersections occupied by own
    stones, territory adds opposing prisoners instead.

    All rules, except short rules, have further phases after
    alternation and before scoring. Towards a game end it is
    often clear which stones will be removed. The additional
    phases allow the players to agree on which stones shall be
    removed. Thereby final removals do not require alternation.

    Whether you score by area or by territory or whether you
    remove by alternation or by agreement should mainly depend
    on which rules are used by people you play with.

    2.3 Which Rules Should I Teach?

    One possibility is to use a board with 9x9 intersections,
    short rules as in 2.1, and count each player's score by
    using a finger to scan the board for his intersections.

    3 IMPORTANT CONCEPTS

    While strategy and tactics virtually remain the same,
    concepts vary in different rules. However, the following
    gives a comprehensive overview on standard terms.

    3.1 Stone, String

    The physical device that colours one intersection in a
    play is a STONE. Two intersections of the board are
    ADJACENT if they have a line but no intersection between
    them. Two intersections with either black, white, or no
    stones on them are CONNECTED if they are adjacent or if
    there is a chain of adjacent intersections of their type
    between them. A REGION consists of an intersection and
    any intersections connected to it. A black or white
    region is called a STRING.

    3.2 Surrounded

    An intersection of one colour is SURROUNDED by another
    colour if each leaving path reaches the other colour first
    after the one colour. Hereby it can only be surrounded
    black by white, white by black, empty by black, or empty
    by white. A region can be surrounded. For strings there is
    an alternative notion of no liberty (or breath). A LIBERTY
    of a string is an empty intersection adjacent to it. Thus
    a string is surrounded if and only if it has no liberty.

    3.3 Removal, Suicide

    A removal empties the intersections of surrounded stones
    if there are any. Hereby removal of opposing stones is
    executed first, if necessary. Rules may either require or
    forbid removal of own stones. This is called suicide or no
    suicide. In practice, suicide might be used for so called ko
    fights or in capturing races.

    3.4 Capture, Prisoner

    Rules that score territory call a removal a capture
    because all removed stones are seriously kept as prisoners.

    3.5 Move, Play, Pass

    The players have alternate turns. On each turn a player makes
    a move that is either a play or a pass. A play places one's
    own stone on an empty intersection. It can then include
    removal of surrounded stones, if any. A pass merely continues
    alternation by giving the opponent the next turn.

    3.6 Compensation

    The first move advantage by black can be compensated by
    compensation points (komi) that are added to the white score
    after the game end. Komi can be adjusted by 0.5 to avoid
    ties. Today integer values for komi for 19x19 boards
    typically range between 5 and 7. For 13x13 boards one should
    use 8, for 9x9 boards 6; however, there is no real consensus
    for small board komi values yet. -
    A weaker player (black) can get the right to place an agreed
    number of compensation stones (handicap) before white's first
    play. Rules may allow free or fixed handicap. Free handicap
    does not apply any restriction. Fixed handicap requires
    traditional placement on set intersections.

    3.7 Phases

    Normally, a game consists of the phases alternation,
    agreement, scoring. A game stop is between alternation and
    agreement, the game end is between agreement and scoring,
    and after scoring both players accept the counted score as
    the result. The main part of the game is the alternation
    phase. Special rules are invoked after it. Typically, two
    successive passes in alternation are the game stop and start
    the agreement phase. In it the players may agree on strings
    to be removed. If they agree, then they remove those strings
    from the board; this ends the game. Sometimes they might
    disagree, then no strings are removed but alternation is
    resumed as if the last game stop did not occur.

    3.8 Recreation

    The position is the pattern of black and white stones on the
    board. Without extra rule a position might be repeated
    infinitely. The easiest rule to prohibit this says: A play
    may not recreate a position. This refers to positions after
    completion of plays, i.e. after possible removals. The rule
    is called "superko". -
    Some rules use concepts different from superko. They combine
    a "2-play rule" with a "long cycle rule". The first says:
    Two successive plays may not recreate a position. The second
    says: If a position is recreated after more than two moves,
    then the game ends either immediately or, as a variant, as
    soon as the players agree, with the result "without result".
    In practice the 2-play rule is sufficient for almost all
    cases. It handles the relevant standard pattern of two
    adjacent intersections. For superko this is just a special
    application.

    3.9 Scoring

    The score is the result after the game end as defined by
    the rules. There are two different scoring methods: area
    scoring and territory scoring. Rules use one of them. Both
    give the same result in almost all cases and both evaluate
    the difference of the black and the white scores. A player's
    AREA score is the sum of intersections with own stones and
    of empty intersections surrounded only by own stones. Simply
    speaking, a player's TERRITORY score is the sum of empty
    intersections surrounded only by own stones and of prisoners
    of opposing colour. With both scoring methods empty
    intersections that are not surrounded by either black or
    white are neutral.

    3.10 Counting

    A score must be determined by some mechanical procedure in
    practice; this is called counting. There are various methods.
    Some rules prescribe one. A possible method is to use one's
    finger to count point by point. Other methods rearrange a lot
    of stones on the board.

    4 PARTICULAR RULES

    Rules vary extremely. However, in practice they often give
    the same result.

    4.1 Short Rules

    Examples of short rules are the Simple Rules or the
    Tromp-Taylor rules. They have no game stop and no agreement.
    Both are superfluous since necessary removals may already be
    performed in the alternation. Two successive passes end the
    game that is scored then. Short rules use area scoring,
    superko, and suicide. Further settings are left for
    tournament rules.

    4.2 American Rules

    These are used by the American Go Association. They use
    situational superko, no suicide, and 7.5 komi. They permit
    free or fixed handicap. Their most remarkable feature is to
    allow one of area scoring or territory scoring. Herefore
    pass stones (one prisoner compensates each pass) and white
    moving last always ensure the same result, regardless of the
    applied scoring method.

    4.3 Chinese Rules

    These are used in continental China and sometimes in other
    countries. Area scoring and no suicide are used.

    4.3.1 Official Chinese Rules

    In practice, ko rules roughly amount to a 2-play rule and a
    long cycle rule. The mentioned superko is overridden. The
    counting is a sophisticated half counting, where empty
    intersections and then after rearrangements stones of one
    colour are added to be compared with half the non-neutral
    intersections. The komi as a half komi is 3.75. In full
    counting, counts and komi would be twice as big.

    4.3.2 Simplified Chinese Rules

    Positional superko is used. A counting method is not
    prescribed. The full komi should be 7.5.

    4.4 Japanese Rules

    The differences mainly affect handling of late game phases
    but often do not alter scores. Japanese rules use some
    traditional territory scoring that attempts to exclude so
    called sekis. No suicide applies. The core of the ko rules
    is a 2-play rule and a long cycle rule. Typically, komi is
    6.5. Fixed handicap should be used. The counting is a
    sophisticated rearrangement of empty intersections and
    filling-in of prisoners.

    4.4.1 Game Finishing Process

    A game finishes with the following process: 1) So called
    dame (neutral points) and defensive moves (necessary
    connections etc. due to occupied dame) are filled.
    2) The hypothetical analysis, which presumes perfect play,
    determines so called life or death of each string and the
    scoring intersections. 3) Without making any approach moves,
    dead stones are removed from scoring intersections and added
    to the prisoners. 4) The score is counted. (2) and (3) do not
    allow to play out life and death since actually filling
    intersections costs points in Japanese rules.

    4.4.2 Official Japanese Rules

    There are the Japanese 1989 Rules, which are used in Japan
    and elsewhere, and the World Amateur Go Championships Rules,
    which are used in some particular tournaments. Korean rules
    are similar to Japanese rules but have a very different text
    and differ in rare positions. Official Japanese rules are
    very incomplete and have messy late game phases. E.g., the
    Japanese 1989 Rules allow filling of dame during alternation,
    after it, or both and have a so called ko-pass-rule for the
    hypothetical analysis. Now professional Japanese rules are
    explained precisely by a rules expert's interpretation called
    "the Japanese 2003 Rules".

    4.4.3 Simplified Japanese Rules

    As a recent invention, they are not used yet. They are
    complete and have clear late game phases. Filling of dame is
    done during alternation.

    4.4.4 Verbal Japanese Rules

    They are used for informal games in many countries and
    undefined, except that the game finishing process is used.
    In a tournament without any official rules of play, disputes
    are not solved due to the rules but with a referee.

    4.5 Ing Rules

    Ing rules use area scoring, suicide, 8 komi with black
    winning ties, and free handicap.

    4.5.1 Official Ing Rules

    The ko rules are a mess but somehow resemble superko.
    Details could fill books. The late game phases are specified
    insufficiently. The peculiar counting method requires 180
    stones of each colour throughout the game, fills any stones
    on the board after the game end, and leaves exactly one
    empty intersection, which determines the winner. The
    official rules are used in professional Taiwanese and some
    sponsored tournaments. Taiwanese amateurs have their own
    rules.

    4.5.2 Simplified Ing Rules

    Positional superko is used. A counting method is not
    prescribed. The late game phases are specified clearly. The
    simplified rules are used in EGF tournaments that are said
    to use Ing rules.

    4.6 New Zealand Rules

    Area scoring, suicide, situational superko, 7 komi, and free
    handicap are used.

    4.7 Go Server Rules

    Every go server has its own and often complicated rules, if
    any, so they cannot be given in detail here. Concerning
    "IGS rules", territory scoring, no suicide, a 2-play rule,
    fixed handicap, three game stopping passes, and captures in
    an agreement phase are used. Details about agreements and
    long cycles are not specified and lead to adjourned games in
    case of doubt. Komi is suggested but may be altered. Counting
    is automatic. "Yahoo" has territory scoring, no suicide, a
    2-play rule, two game stopping passes; long cycles and
    disagreements are not handled properly. On "email servers"
    players must agree on any rules. -
    Typically territory scoring on a go server means that neither
    points in any sekis are excluded nor pass stones are used.
    Thus while the Japanese seki exception is abandoned,
    disagreements about removals may lead to games without result
    since playing out can cost points.

    4.8 International Rules

    The international mailing list go-rules has proposed
    international rules, however, none are adopted yet. The core
    rules of play shall be clear, complete, and correct.
    Currently alternative texts are offered for suicide,
    recreation, and scoring. Especially unification of scoring
    methods is advocated.

    4.9 EGF Rules

    The EGF uses the Simplified Ing Rules with 8 komi (black
    wins ties) in Ing sponsored tournaments and the Nihon Kiin
    1989 Rules with 6.5 komi in Japanese/Korean sponsored
    tournaments. If significantly the European Go Championship
    has both kinds of sponsors, then boards 1-16 use the Nihon
    Kiin 1989 Rules and boards 17+ the Simplified Ing Rules.
    However, time settings depend on ranks.

    5 TROUBLESOME DETAILS

    5.1 Colour Choice

    In even games typically the colours are randomly chosen. In
    handicap games black receives the handicap stones. -
    A manual method for randomly choosing colours is called
    nigiri. The older player hides a number of white stones
    taken from the bowl, the opponent takes one or two black
    stones to guess the parity, and the parity of the number of
    white stones is revealed. If the opponent guesses right,
    then he takes black, else he takes white.

    5.2 Pass Stones

    Some rules use pass stones. A passing player adds one own
    stone to the prisoners. As a consequence, captures before
    the game end can be resolved in alternation without any loss
    because any not answered approach move is compensated by one
    pass stone. With traditional territory scoring that uses no
    pass stones definition problems arise due to this missing
    option. Modern territory scoring or equivalence scoring use
    pass stones.

    5.3 Equivalence

    Area scoring and territory scoring are close because either
    intersections occupied by own stones or opposing prisoners
    are used. Essentially, every prisoner is a stone removed
    from some intersection. For area it scores one point less
    for the stone's player while for territory it scores one
    point more for his opponent. This is equal. Exact equality
    for the entire game must also consider passes by using pass
    stones and an equal number of moves by requiring white to
    pass last. This is done by equivalence scoring.

    5.4 Meaning of Agreement Removals

    Removals in an agreement phase under area scoring are fair
    because they may as well occur in alternation. Removing a
    stone due to agreement includes its then empty intersection
    and all adjacent empty intersections in the score. Removing
    a stone by means of alternation includes its then empty
    intersection and all adjacent newly occupied intersections
    in the score. -
    With traditional territory scoring this is not possible
    since stones on the board do not score. Thus final captures
    must occur after the game end due to attempted definitions
    in the rules.

    5.5 Practical Scoring Differences

    Since area scoring and modern territory scoring using pass
    stones are equal, correct play is the same for both. Apart
    from Japanese rules exceptions like not scoring empty
    intersections especially in asymmetrical coexistences or
    like a pass-for-ko-rule, traditional territory scoring can
    make a different winner in practically ca. every 10000th
    even game. This is so rare because of a parity feature
    combined with a scarcely odd number of intersections that
    are in coexistences but do not score for area at the game
    end. With area scoring a komi change from 1.5, 3.5, 5.5, ...
    to 2.5, 4.5, 6.5, ... almost always would not change the
    winner. So altough occupying the last empty intersections
    that would otherwise not score just before a game stop gains
    one point each, alternately doing so leaves a total
    advantage of at most one point. Due to the parity feature
    the player to get it is predetermined when this occupation
    starts. More importantly, one final ko is worth 1 point under
    traditional territory scoring but 2 or rarely 4 points under
    area scoring. Rare one-sided points in coexistences provide
    only area. Other practical differences are even rarer. Cute
    players include the stones in their endgame value counts
    during the middle of an area scoring game.

    5.6 Stone Scoring

    In ancient times stone scoring was popular. Only stones on
    the board are scored. Thus empty intersections surrounded by
    own stones are filled until necessary so called eyes remain.
    Disconnected stones require more eyes in total, the so
    called group tax.

    5.7 Old Ing Scoring

    Old Ing rules allowed fractional scores by assigning points
    to neutral empty regions due to the percentage of black and
    white stones surrounding every region.

    5.8 Primitive Rules

    They do not have passes. Alternation ends when a player
    loses due to no legal play. Games can be extremely long and
    include special strategies, so called pass fights. Primitive
    rules (also called no pass rules or Conway rules) can be
    useful in mathematics.

    5.9 Tradition

    Historically, exceptions arose, which some like as such
    especially together with Japanese style rules. So called
    sekis are excluded from the score. Special positions, termed
    precedents, have special rules. Modern Japanese rules have
    generalized a lot of them by a pass-for-ko-rule. After the
    game stop or after the game end and particularly in
    hypothetical play a stone captured in a possible 2-play cycle
    may not be recaptured unless before a pass is made that
    specifies the particular 2-play cycle.

    5.10 Positional / Situational Superko

    Positional superko prohibits a play that recreates a position.
    Situational superko refers to the situation, i.e. to the
    position together with the right to move. So a play is
    prohibited if it recreates a position while the same player
    has the right to move. In practice the differences are
    extremely rare.

    5.11 Handicap Recompensation

    With area scoring handicap stones beyond the first provide
    a potential extra area of one point per handicap stone. Komi
    for white may consider this. Recompensation, H-1 points for H
    handicap stones, is virtually only used together with
    American rules.

    5.12 Mathematics

    Go is a complete information game, i.e. at every move each
    player knows the entire game situation. Hence theoretically
    an algorithm could determine perfect play. However, due to
    the complexity of the game with N intersections, for which
    it is provably impossible to devise a polynomial time
    solution, perfect play or ideal komi are unknown. What one
    does know is that in a game without komi the first player wins
    or ties and that perfect play is independent of set komi. Many
    other propositions have been discovered, some of which
    describe the relation between area and territory scoring, solve
    tiny endgame positions or cyclical behaviour. -
    Go is a very complex game! According to John Tromp, the number
    of legal positions is:

    208168199381979984699478633344862770286522453884530548425 639456820927419612738015378525648451698519643907259916015 628128546089888314427129715319317557736620397247064840935

    For positional superko, no passes, and no resignation, the
    number of possible games is smaller than N**L(N) because L(N)
    also restricts the maximal number of moves per game and there
    are at most N possible intersections per move. (The sign ** is
    a text file notation for "to the power".) -
    Extremely modest estimates look like 10**N, which is based on
    an assumption of 10 reasonable intersections per move. A
    popular estimate for 19x19 go is 10**761, which must have
    originated from a typo and should be 10**361, if at all...
    These types of estimates are so popular because humans cannot
    even imagine the suggested number of atoms in the universe,
    10**80. For comparison, 3**361 is ca. 10**172.

    6 TOURNAMENT RULES

    6.1 Special Game Ends

    If the score considering the komi is zero, then the game is a
    tie and should be treated as 0.5 won games for each. Special
    rules or undue behaviour like sincere lateness might result
    in a referee declaring a win by forfeit, 0:0, or 1:1,
    whichever is most appropriate.

    6.2 Tournament Systems

    A tournament might consist of several stages, of which each
    has a seed and a system. A seed appropriately restricts
    participation, e.g. due to qualification. The most important
    systems are match, league, knockout, Swiss, McMahon. There
    are many others and hybrids. A system must fit the aims of a
    tournament. A sufficient number of rounds, a proper seed,
    and colour variation ensure a fair determination of the best
    player. -
    A match takes place between two players that either play a
    set number of games to see who wins more or a maximal number
    of games to see who wins a predetermined number of games
    first. In a league a small, usually even number of players
    performs a round-robin tournament, so that in each round all
    players play and every two players play against each other,
    one game e.g. A knockout preferably starts with a number of
    players that is a power of two. Losing players are eliminated,
    winning players continue until the winner remains. -
    In a Swiss system before each round each player's achieved
    number of wins is used to pair players with equal numbers as
    far as possible. So all players play all rounds and some time
    the best player will emerge. However, with greatly varying
    strengths too many rounds would be needed. So Swiss is only
    useful for particular events or handicap tournaments.
    McMahon is the refinement of Swiss. Before the start of the
    tournament all players are classified in rank groups, with
    ranks R from 0 to T. This means that one assumes a preceding
    Swiss tournament where every player has already won R games.
    Then in the McMahon tournament the strongest players, who
    deserve the rank T, compete for the top places. In practice,
    one uses a bar B, that is 1 or 2 ranks below T, so that all
    ranks above B are contracted to B and also players slightly
    weaker than the top players get their chance. All players in
    a McMahon play roughly equal opponents; if they win or lose,
    then the opponents will be stronger or weaker.

    6.3 Tie Breakers

    Tie breakers can refine pairings or results. Typically the
    first criterion is the number of wins (or McMahon points);
    all further criteria, if any, are tie breakers. They attempt
    a refinement where a low number of rounds and a tournament
    system do not guarantee sufficient distinction between
    players' achievements. However, they must be applied with
    care since they are only marginally better than coin tossing.
    Examples of tie breakers are direct comparison, which
    acknowledges the winner of a game between two players in
    question, and SOS, which is the Sum of Opponents' Scores. -
    The possible degree of quality of tie breakers is subject to
    discussion. It depends on tournament system, whether only the
    top or all players shall be distinguished, and other factors.
    An alternative to the usage of tie breakers for the final
    results ordering is issuing shared places for all players
    with the same number of wins (or McMahon points). - One must
    fairly assign tie breaker points for opponents missing in
    some round; enforcing participation is preferable especially
    for top players.

    6.4 Pairing

    Pairings must be fair, precise, and consider prior
    achievements during a tournament. One should consider colour
    balance and no pair twice, one might also aim at avoiding a
    pair of players from the same club or country, depending on
    a tournament's intentions. Pairings might be done manually
    in small tournaments; for most tournaments pairing programs
    should be used. These can create fair pairings convincingly,
    some even watch global balance.

    6.5 Thinking Times

    The age of killing each other by greater endurance has gone.
    Clocks are used to count each player's remaining thinking
    time. Typically, every game has a basic time and overtime
    periods. Exceeding a time limit loses a game. Basic time
    might be 9 hours for a professional top game, 10 minutes for
    a lightning game, or something in between that fits a
    tournament's intentions. An overtime period requires a fixed
    number of moves within a predetermined period, e.g. 1 move
    within 60 seconds. A move is finished by pressing the clock.
    - Many variants or other time systems exist, e.g., increasing
    numbers of moves in further overtime periods, penalty points
    for entering further periods, full usage of every overtime
    period, thinking time working like an hour glass, etc.

    6.6 Tournament Rules

    Every tournament uses an announced set of tournament rules.
    They especially specify the used set for the core rules of
    play, the tournament system, tie breakers, the pairing
    method, the winning criteria, compensation methods,
    thinking times, direction, jurisdiction, adjournment
    methods, penalities for being late, etc. Tournament rules
    often deal with details. Not everything can be predicted, so
    a sportsmanlike spirit is mentioned. Finally, it should be
    clear which of several rule sets takes precedence.

    6.7 Tournament Organization

    A regional tournament can be organized by a club. Big events
    can be held at the request of an association or federation,
    who also supervise. A tournament organization is responsible
    for providing a venue and playing material. It must be
    distinguished from the tournament director and his assistant
    directors, who perform the particular tasks of pairing,
    collecting results, and ensuring smooth running. Shared
    power furthermore demands independent referees.

    6.8 Jurisdiction

    Before the start of a tournament valid instances of a
    jurisdiction as well as the persons to be referees must be
    clear. Typically, for a tournament itself there is one
    referee as the first instance and a body of three referees
    as the second instance. For very peculiar cases a federation
    could have a third and final instance. Some tournament rules
    replace the second instance by a single person, called chief
    referee; to avoid confusion he ought not to judge as the
    first instance. Players should respect the referees' tough
    job of mediation or decision; referees should seriously
    enforce the rules.

    6.9 Prizes

    The first places of a tournament invoke major prizes. E.g.
    the first, second, third places might get 3/6, 2/6, 1/6 of
    the available money. In a tournament with many weaker
    players it is a good idea to provide some prizes for all
    other players that win most rounds as well. While prizes can
    be money, books, trophies, etc., one should remember that
    money is most universally accepted and trophies serve the
    media better than the winners. -
    On a related topic, a side event lottery must give equal
    chances to all participants. This is only achieved by using
    one lot for each.

    7 Links

    Most rules information, links, short rules: http://home.snafu.de/jasiek/rules.html

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Bill@21:1/5 to Robert Jasiek on Fri Oct 13 00:02:50 2017
    Robert Jasiek wrote:
    Title: Rules FAQ
    Author: Robert Jasiek <jasiek@snafu.de>

    To the author (Robert Jasiek),

    The first paragraph states:
    "Beginners should read
    especially chapters 2 and 3, players chapters 3 to 5,
    tournament players and organizers chapter 6."


    The word "chapters" should be capitalized in the three places it is used above. I hope that helps!

    Bill




    Frequency: monthly
    Last Update: 2016-02-12; First Day: 1999-04-12
    Distribution: rec.games.go
    Copyright: free non-commercial usage for promotion

    0 CONTENTS

    1 Purpose of this Paper
    2 Information for Beginners
    3 Important Concepts
    4 Particular Rules
    5 Troublesome Details
    6 Tournament Rules
    7 Links

    1 PURPOSE OF THIS PAPER

    This paper is a basic reference for important rules terms,
    rules, and tournament rules. Beginners should read
    especially chapters 2 and 3, players chapters 3 to 5,
    tournament players and organizers chapter 6.

    2 INFORMATION FOR BEGINNERS
    2.1 What Must I Know as a Beginner?

    The game is played on a grid board. Typically it has 19x19
    intersections, but 9x9 are also fine. Two players compete.
    The first player uses black stones, the other white.

    The players alternate. A player may play or pass. Playing
    is putting one's own stone on an empty intersection and
    removing any surrounded opposing stones. To avoid
    cycles, a play may not recreate any prior configuration of
    all stones on the board.

    Two successive passes end the game. Then the player with
    more intersections wins. Intersections are his if only his
    stones occupy or surround them.

    2.2 Which Rules do I Need as a Beginner?

    You can play with short rules as in 2.1. Other rules may
    be different, but the game is the same, i. e. strategy,
    tactics, and the score do not change. Extremely rare
    exceptions confirm this rule.

    The winner can be determined by area or by territory.
    Either includes empty intersections surrounded only by own
    stones. While area adds intersections occupied by own
    stones, territory adds opposing prisoners instead.

    All rules, except short rules, have further phases after
    alternation and before scoring. Towards a game end it is
    often clear which stones will be removed. The additional
    phases allow the players to agree on which stones shall be
    removed. Thereby final removals do not require alternation.

    Whether you score by area or by territory or whether you
    remove by alternation or by agreement should mainly depend
    on which rules are used by people you play with.

    2.3 Which Rules Should I Teach?

    One possibility is to use a board with 9x9 intersections,
    short rules as in 2.1, and count each player's score by
    using a finger to scan the board for his intersections.

    3 IMPORTANT CONCEPTS

    While strategy and tactics virtually remain the same,
    concepts vary in different rules. However, the following
    gives a comprehensive overview on standard terms.

    3.1 Stone, String

    The physical device that colours one intersection in a
    play is a STONE. Two intersections of the board are
    ADJACENT if they have a line but no intersection between
    them. Two intersections with either black, white, or no
    stones on them are CONNECTED if they are adjacent or if
    there is a chain of adjacent intersections of their type
    between them. A REGION consists of an intersection and
    any intersections connected to it. A black or white
    region is called a STRING.

    3.2 Surrounded

    An intersection of one colour is SURROUNDED by another
    colour if each leaving path reaches the other colour first
    after the one colour. Hereby it can only be surrounded
    black by white, white by black, empty by black, or empty
    by white. A region can be surrounded. For strings there is
    an alternative notion of no liberty (or breath). A LIBERTY
    of a string is an empty intersection adjacent to it. Thus
    a string is surrounded if and only if it has no liberty.

    3.3 Removal, Suicide

    A removal empties the intersections of surrounded stones
    if there are any. Hereby removal of opposing stones is
    executed first, if necessary. Rules may either require or
    forbid removal of own stones. This is called suicide or no
    suicide. In practice, suicide might be used for so called ko
    fights or in capturing races.

    3.4 Capture, Prisoner

    Rules that score territory call a removal a capture
    because all removed stones are seriously kept as prisoners.

    3.5 Move, Play, Pass

    The players have alternate turns. On each turn a player makes
    a move that is either a play or a pass. A play places one's
    own stone on an empty intersection. It can then include
    removal of surrounded stones, if any. A pass merely continues
    alternation by giving the opponent the next turn.

    3.6 Compensation

    The first move advantage by black can be compensated by
    compensation points (komi) that are added to the white score
    after the game end. Komi can be adjusted by 0.5 to avoid
    ties. Today integer values for komi for 19x19 boards
    typically range between 5 and 7. For 13x13 boards one should
    use 8, for 9x9 boards 6; however, there is no real consensus
    for small board komi values yet. -
    A weaker player (black) can get the right to place an agreed
    number of compensation stones (handicap) before white's first
    play. Rules may allow free or fixed handicap. Free handicap
    does not apply any restriction. Fixed handicap requires
    traditional placement on set intersections.

    3.7 Phases

    Normally, a game consists of the phases alternation,
    agreement, scoring. A game stop is between alternation and
    agreement, the game end is between agreement and scoring,
    and after scoring both players accept the counted score as
    the result. The main part of the game is the alternation
    phase. Special rules are invoked after it. Typically, two
    successive passes in alternation are the game stop and start
    the agreement phase. In it the players may agree on strings
    to be removed. If they agree, then they remove those strings
    from the board; this ends the game. Sometimes they might
    disagree, then no strings are removed but alternation is
    resumed as if the last game stop did not occur.

    3.8 Recreation

    The position is the pattern of black and white stones on the
    board. Without extra rule a position might be repeated
    infinitely. The easiest rule to prohibit this says: A play
    may not recreate a position. This refers to positions after
    completion of plays, i.e. after possible removals. The rule
    is called "superko". -
    Some rules use concepts different from superko. They combine
    a "2-play rule" with a "long cycle rule". The first says:
    Two successive plays may not recreate a position. The second
    says: If a position is recreated after more than two moves,
    then the game ends either immediately or, as a variant, as
    soon as the players agree, with the result "without result".
    In practice the 2-play rule is sufficient for almost all
    cases. It handles the relevant standard pattern of two
    adjacent intersections. For superko this is just a special
    application.

    3.9 Scoring

    The score is the result after the game end as defined by
    the rules. There are two different scoring methods: area
    scoring and territory scoring. Rules use one of them. Both
    give the same result in almost all cases and both evaluate
    the difference of the black and the white scores. A player's
    AREA score is the sum of intersections with own stones and
    of empty intersections surrounded only by own stones. Simply
    speaking, a player's TERRITORY score is the sum of empty
    intersections surrounded only by own stones and of prisoners
    of opposing colour. With both scoring methods empty
    intersections that are not surrounded by either black or
    white are neutral.

    3.10 Counting

    A score must be determined by some mechanical procedure in
    practice; this is called counting. There are various methods.
    Some rules prescribe one. A possible method is to use one's
    finger to count point by point. Other methods rearrange a lot
    of stones on the board.

    4 PARTICULAR RULES

    Rules vary extremely. However, in practice they often give
    the same result.

    4.1 Short Rules

    Examples of short rules are the Simple Rules or the
    Tromp-Taylor rules. They have no game stop and no agreement.
    Both are superfluous since necessary removals may already be
    performed in the alternation. Two successive passes end the
    game that is scored then. Short rules use area scoring,
    superko, and suicide. Further settings are left for
    tournament rules.

    4.2 American Rules

    These are used by the American Go Association. They use
    situational superko, no suicide, and 7.5 komi. They permit
    free or fixed handicap. Their most remarkable feature is to
    allow one of area scoring or territory scoring. Herefore
    pass stones (one prisoner compensates each pass) and white
    moving last always ensure the same result, regardless of the
    applied scoring method.

    4.3 Chinese Rules

    These are used in continental China and sometimes in other
    countries. Area scoring and no suicide are used.

    4.3.1 Official Chinese Rules

    In practice, ko rules roughly amount to a 2-play rule and a
    long cycle rule. The mentioned superko is overridden. The
    counting is a sophisticated half counting, where empty
    intersections and then after rearrangements stones of one
    colour are added to be compared with half the non-neutral
    intersections. The komi as a half komi is 3.75. In full
    counting, counts and komi would be twice as big.

    4.3.2 Simplified Chinese Rules

    Positional superko is used. A counting method is not
    prescribed. The full komi should be 7.5.

    4.4 Japanese Rules

    The differences mainly affect handling of late game phases
    but often do not alter scores. Japanese rules use some
    traditional territory scoring that attempts to exclude so
    called sekis. No suicide applies. The core of the ko rules
    is a 2-play rule and a long cycle rule. Typically, komi is
    6.5. Fixed handicap should be used. The counting is a
    sophisticated rearrangement of empty intersections and
    filling-in of prisoners.

    4.4.1 Game Finishing Process

    A game finishes with the following process: 1) So called
    dame (neutral points) and defensive moves (necessary
    connections etc. due to occupied dame) are filled.
    2) The hypothetical analysis, which presumes perfect play,
    determines so called life or death of each string and the
    scoring intersections. 3) Without making any approach moves,
    dead stones are removed from scoring intersections and added
    to the prisoners. 4) The score is counted. (2) and (3) do not
    allow to play out life and death since actually filling
    intersections costs points in Japanese rules.

    4.4.2 Official Japanese Rules

    There are the Japanese 1989 Rules, which are used in Japan
    and elsewhere, and the World Amateur Go Championships Rules,
    which are used in some particular tournaments. Korean rules
    are similar to Japanese rules but have a very different text
    and differ in rare positions. Official Japanese rules are
    very incomplete and have messy late game phases. E.g., the
    Japanese 1989 Rules allow filling of dame during alternation,
    after it, or both and have a so called ko-pass-rule for the
    hypothetical analysis. Now professional Japanese rules are
    explained precisely by a rules expert's interpretation called
    "the Japanese 2003 Rules".

    4.4.3 Simplified Japanese Rules

    As a recent invention, they are not used yet. They are
    complete and have clear late game phases. Filling of dame is
    done during alternation.

    4.4.4 Verbal Japanese Rules

    They are used for informal games in many countries and
    undefined, except that the game finishing process is used.
    In a tournament without any official rules of play, disputes
    are not solved due to the rules but with a referee.

    4.5 Ing Rules

    Ing rules use area scoring, suicide, 8 komi with black
    winning ties, and free handicap.

    4.5.1 Official Ing Rules

    The ko rules are a mess but somehow resemble superko.
    Details could fill books. The late game phases are specified
    insufficiently. The peculiar counting method requires 180
    stones of each colour throughout the game, fills any stones
    on the board after the game end, and leaves exactly one
    empty intersection, which determines the winner. The
    official rules are used in professional Taiwanese and some
    sponsored tournaments. Taiwanese amateurs have their own
    rules.

    4.5.2 Simplified Ing Rules

    Positional superko is used. A counting method is not
    prescribed. The late game phases are specified clearly. The
    simplified rules are used in EGF tournaments that are said
    to use Ing rules.

    4.6 New Zealand Rules

    Area scoring, suicide, situational superko, 7 komi, and free
    handicap are used.

    4.7 Go Server Rules

    Every go server has its own and often complicated rules, if
    any, so they cannot be given in detail here. Concerning
    "IGS rules", territory scoring, no suicide, a 2-play rule,
    fixed handicap, three game stopping passes, and captures in
    an agreement phase are used. Details about agreements and
    long cycles are not specified and lead to adjourned games in
    case of doubt. Komi is suggested but may be altered. Counting
    is automatic. "Yahoo" has territory scoring, no suicide, a
    2-play rule, two game stopping passes; long cycles and
    disagreements are not handled properly. On "email servers"
    players must agree on any rules. -
    Typically territory scoring on a go server means that neither
    points in any sekis are excluded nor pass stones are used.
    Thus while the Japanese seki exception is abandoned,
    disagreements about removals may lead to games without result
    since playing out can cost points.

    4.8 International Rules

    The international mailing list go-rules has proposed
    international rules, however, none are adopted yet. The core
    rules of play shall be clear, complete, and correct.
    Currently alternative texts are offered for suicide,
    recreation, and scoring. Especially unification of scoring
    methods is advocated.

    4.9 EGF Rules

    The EGF uses the Simplified Ing Rules with 8 komi (black
    wins ties) in Ing sponsored tournaments and the Nihon Kiin
    1989 Rules with 6.5 komi in Japanese/Korean sponsored
    tournaments. If significantly the European Go Championship
    has both kinds of sponsors, then boards 1-16 use the Nihon
    Kiin 1989 Rules and boards 17+ the Simplified Ing Rules.
    However, time settings depend on ranks.

    5 TROUBLESOME DETAILS

    5.1 Colour Choice

    In even games typically the colours are randomly chosen. In
    handicap games black receives the handicap stones. -
    A manual method for randomly choosing colours is called
    nigiri. The older player hides a number of white stones
    taken from the bowl, the opponent takes one or two black
    stones to guess the parity, and the parity of the number of
    white stones is revealed. If the opponent guesses right,
    then he takes black, else he takes white.

    5.2 Pass Stones

    Some rules use pass stones. A passing player adds one own
    stone to the prisoners. As a consequence, captures before
    the game end can be resolved in alternation without any loss
    because any not answered approach move is compensated by one
    pass stone. With traditional territory scoring that uses no
    pass stones definition problems arise due to this missing
    option. Modern territory scoring or equivalence scoring use
    pass stones.

    5.3 Equivalence

    Area scoring and territory scoring are close because either
    intersections occupied by own stones or opposing prisoners
    are used. Essentially, every prisoner is a stone removed
    from some intersection. For area it scores one point less
    for the stone's player while for territory it scores one
    point more for his opponent. This is equal. Exact equality
    for the entire game must also consider passes by using pass
    stones and an equal number of moves by requiring white to
    pass last. This is done by equivalence scoring.

    5.4 Meaning of Agreement Removals

    Removals in an agreement phase under area scoring are fair
    because they may as well occur in alternation. Removing a
    stone due to agreement includes its then empty intersection
    and all adjacent empty intersections in the score. Removing
    a stone by means of alternation includes its then empty
    intersection and all adjacent newly occupied intersections
    in the score. -
    With traditional territory scoring this is not possible
    since stones on the board do not score. Thus final captures
    must occur after the game end due to attempted definitions
    in the rules.

    5.5 Practical Scoring Differences

    Since area scoring and modern territory scoring using pass
    stones are equal, correct play is the same for both. Apart
    from Japanese rules exceptions like not scoring empty
    intersections especially in asymmetrical coexistences or
    like a pass-for-ko-rule, traditional territory scoring can
    make a different winner in practically ca. every 10000th
    even game. This is so rare because of a parity feature
    combined with a scarcely odd number of intersections that
    are in coexistences but do not score for area at the game
    end. With area scoring a komi change from 1.5, 3.5, 5.5, ...
    to 2.5, 4.5, 6.5, ... almost always would not change the
    winner. So altough occupying the last empty intersections
    that would otherwise not score just before a game stop gains
    one point each, alternately doing so leaves a total
    advantage of at most one point. Due to the parity feature
    the player to get it is predetermined when this occupation
    starts. More importantly, one final ko is worth 1 point under
    traditional territory scoring but 2 or rarely 4 points under
    area scoring. Rare one-sided points in coexistences provide
    only area. Other practical differences are even rarer. Cute
    players include the stones in their endgame value counts
    during the middle of an area scoring game.

    5.6 Stone Scoring

    In ancient times stone scoring was popular. Only stones on
    the board are scored. Thus empty intersections surrounded by
    own stones are filled until necessary so called eyes remain.
    Disconnected stones require more eyes in total, the so
    called group tax.

    5.7 Old Ing Scoring

    Old Ing rules allowed fractional scores by assigning points
    to neutral empty regions due to the percentage of black and
    white stones surrounding every region.

    5.8 Primitive Rules

    They do not have passes. Alternation ends when a player
    loses due to no legal play. Games can be extremely long and
    include special strategies, so called pass fights. Primitive
    rules (also called no pass rules or Conway rules) can be
    useful in mathematics.

    5.9 Tradition

    Historically, exceptions arose, which some like as such
    especially together with Japanese style rules. So called
    sekis are excluded from the score. Special positions, termed
    precedents, have special rules. Modern Japanese rules have
    generalized a lot of them by a pass-for-ko-rule. After the
    game stop or after the game end and particularly in
    hypothetical play a stone captured in a possible 2-play cycle
    may not be recaptured unless before a pass is made that
    specifies the particular 2-play cycle.

    5.10 Positional / Situational Superko

    Positional superko prohibits a play that recreates a position.
    Situational superko refers to the situation, i.e. to the
    position together with the right to move. So a play is
    prohibited if it recreates a position while the same player
    has the right to move. In practice the differences are
    extremely rare.

    5.11 Handicap Recompensation

    With area scoring handicap stones beyond the first provide
    a potential extra area of one point per handicap stone. Komi
    for white may consider this. Recompensation, H-1 points for H
    handicap stones, is virtually only used together with
    American rules.

    5.12 Mathematics

    Go is a complete information game, i.e. at every move each
    player knows the entire game situation. Hence theoretically
    an algorithm could determine perfect play. However, due to
    the complexity of the game with N intersections, for which
    it is provably impossible to devise a polynomial time
    solution, perfect play or ideal komi are unknown. What one
    does know is that in a game without komi the first player wins
    or ties and that perfect play is independent of set komi. Many
    other propositions have been discovered, some of which
    describe the relation between area and territory scoring, solve
    tiny endgame positions or cyclical behaviour. -
    Go is a very complex game! According to John Tromp, the number
    of legal positions is:

    208168199381979984699478633344862770286522453884530548425 639456820927419612738015378525648451698519643907259916015 628128546089888314427129715319317557736620397247064840935

    For positional superko, no passes, and no resignation, the
    number of possible games is smaller than N**L(N) because L(N)
    also restricts the maximal number of moves per game and there
    are at most N possible intersections per move. (The sign ** is
    a text file notation for "to the power".) -
    Extremely modest estimates look like 10**N, which is based on
    an assumption of 10 reasonable intersections per move. A
    popular estimate for 19x19 go is 10**761, which must have
    originated from a typo and should be 10**361, if at all...
    These types of estimates are so popular because humans cannot
    even imagine the suggested number of atoms in the universe,
    10**80. For comparison, 3**361 is ca. 10**172.

    6 TOURNAMENT RULES

    6.1 Special Game Ends

    If the score considering the komi is zero, then the game is a
    tie and should be treated as 0.5 won games for each. Special
    rules or undue behaviour like sincere lateness might result
    in a referee declaring a win by forfeit, 0:0, or 1:1,
    whichever is most appropriate.

    6.2 Tournament Systems

    A tournament might consist of several stages, of which each
    has a seed and a system. A seed appropriately restricts
    participation, e.g. due to qualification. The most important
    systems are match, league, knockout, Swiss, McMahon. There
    are many others and hybrids. A system must fit the aims of a
    tournament. A sufficient number of rounds, a proper seed,
    and colour variation ensure a fair determination of the best
    player. -
    A match takes place between two players that either play a
    set number of games to see who wins more or a maximal number
    of games to see who wins a predetermined number of games
    first. In a league a small, usually even number of players
    performs a round-robin tournament, so that in each round all
    players play and every two players play against each other,
    one game e.g. A knockout preferably starts with a number of
    players that is a power of two. Losing players are eliminated,
    winning players continue until the winner remains. -
    In a Swiss system before each round each player's achieved
    number of wins is used to pair players with equal numbers as
    far as possible. So all players play all rounds and some time
    the best player will emerge. However, with greatly varying
    strengths too many rounds would be needed. So Swiss is only
    useful for particular events or handicap tournaments.
    McMahon is the refinement of Swiss. Before the start of the
    tournament all players are classified in rank groups, with
    ranks R from 0 to T. This means that one assumes a preceding
    Swiss tournament where every player has already won R games.
    Then in the McMahon tournament the strongest players, who
    deserve the rank T, compete for the top places. In practice,
    one uses a bar B, that is 1 or 2 ranks below T, so that all
    ranks above B are contracted to B and also players slightly
    weaker than the top players get their chance. All players in
    a McMahon play roughly equal opponents; if they win or lose,
    then the opponents will be stronger or weaker.

    6.3 Tie Breakers

    Tie breakers can refine pairings or results. Typically the
    first criterion is the number of wins (or McMahon points);
    all further criteria, if any, are tie breakers. They attempt
    a refinement where a low number of rounds and a tournament
    system do not guarantee sufficient distinction between
    players' achievements. However, they must be applied with
    care since they are only marginally better than coin tossing.
    Examples of tie breakers are direct comparison, which
    acknowledges the winner of a game between two players in
    question, and SOS, which is the Sum of Opponents' Scores. -
    The possible degree of quality of tie breakers is subject to
    discussion. It depends on tournament system, whether only the
    top or all players shall be distinguished, and other factors.
    An alternative to the usage of tie breakers for the final
    results ordering is issuing shared places for all players
    with the same number of wins (or McMahon points). - One must
    fairly assign tie breaker points for opponents missing in
    some round; enforcing participation is preferable especially
    for top players.

    6.4 Pairing

    Pairings must be fair, precise, and consider prior
    achievements during a tournament. One should consider colour
    balance and no pair twice, one might also aim at avoiding a
    pair of players from the same club or country, depending on
    a tournament's intentions. Pairings might be done manually
    in small tournaments; for most tournaments pairing programs
    should be used. These can create fair pairings convincingly,
    some even watch global balance.

    6.5 Thinking Times

    The age of killing each other by greater endurance has gone.
    Clocks are used to count each player's remaining thinking
    time. Typically, every game has a basic time and overtime
    periods. Exceeding a time limit loses a game. Basic time
    might be 9 hours for a professional top game, 10 minutes for
    a lightning game, or something in between that fits a
    tournament's intentions. An overtime period requires a fixed
    number of moves within a predetermined period, e.g. 1 move
    within 60 seconds. A move is finished by pressing the clock.
    - Many variants or other time systems exist, e.g., increasing
    numbers of moves in further overtime periods, penalty points
    for entering further periods, full usage of every overtime
    period, thinking time working like an hour glass, etc.

    6.6 Tournament Rules

    Every tournament uses an announced set of tournament rules.
    They especially specify the used set for the core rules of
    play, the tournament system, tie breakers, the pairing
    method, the winning criteria, compensation methods,
    thinking times, direction, jurisdiction, adjournment
    methods, penalities for being late, etc. Tournament rules
    often deal with details. Not everything can be predicted, so
    a sportsmanlike spirit is mentioned. Finally, it should be
    clear which of several rule sets takes precedence.

    6.7 Tournament Organization

    A regional tournament can be organized by a club. Big events
    can be held at the request of an association or federation,
    who also supervise. A tournament organization is responsible
    for providing a venue and playing material. It must be
    distinguished from the tournament director and his assistant
    directors, who perform the particular tasks of pairing,
    collecting results, and ensuring smooth running. Shared
    power furthermore demands independent referees.

    6.8 Jurisdiction

    Before the start of a tournament valid instances of a
    jurisdiction as well as the persons to be referees must be
    clear. Typically, for a tournament itself there is one
    referee as the first instance and a body of three referees
    as the second instance. For very peculiar cases a federation
    could have a third and final instance. Some tournament rules
    replace the second instance by a single person, called chief
    referee; to avoid confusion he ought not to judge as the
    first instance. Players should respect the referees' tough
    job of mediation or decision; referees should seriously
    enforce the rules.

    6.9 Prizes

    The first places of a tournament invoke major prizes. E.g.
    the first, second, third places might get 3/6, 2/6, 1/6 of
    the available money. In a tournament with many weaker
    players it is a good idea to provide some prizes for all
    other players that win most rounds as well. While prizes can
    be money, books, trophies, etc., one should remember that
    money is most universally accepted and trophies serve the
    media better than the winners. -
    On a related topic, a side event lottery must give equal
    chances to all participants. This is only achieved by using
    one lot for each.

    7 Links

    Most rules information, links, short rules: http://home.snafu.de/jasiek/rules.html

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Rainer Rosenthal@21:1/5 to All on Fri Oct 13 07:43:34 2017
    Am 13.10.2017 um 06:02 schrieb Bill:

    The word "chapters" should be capitalized in the three places it is used above.  I hope that helps!

    I've never come across "positive cynism".
    I didn't even know there existed something like that.

    Cheers,
    Rainer

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Bill@21:1/5 to Rainer Rosenthal on Fri Oct 13 05:48:46 2017
    Rainer Rosenthal wrote:
    Am 13.10.2017 um 06:02 schrieb Bill:

    The word "chapters" should be capitalized in the three places it is
    used above. I hope that helps!

    I've never come across "positive cynism".
    I didn't even know there existed something like that.

    Cheers,
    Rainer

    The second sentence says:

    "The game is played on a grid board. Typically it has 19x19
    intersections, but 9x9 are also fine."

    --In place of "The game", I would just write "Go"; this is my only
    stylistic comment.
    --What is a "grid board"?
    --What does "it" refer to? The answer is unclear from what is written.
    --The word "are" should be "is".
    --what does "fine" mean in this context? Do you really mean 81 is also fine? --Is 13x13 = 169 not fine? How is the reader supposed to interpret the
    symbol "x"?


    We are only on the second sentence, but it will be a good start to
    (finally) get the first 2 sentences in order. I hope that these
    comments are helpful! Try hard (everyone) not to make any derogatory
    remarks about this document, until we have finished editing it! At this
    point, I would be ashamed to let my 7th grade English teacher see it...
    But surely there is much potential.

    Cheers,
    Bill

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Bates@21:1/5 to Bill on Fri Oct 13 19:46:42 2017
    Bill wrote:

    The second sentence says:

    "The game is played on a grid board. Typically it has 19x19
    intersections, but 9x9 are also fine."

    --In place of "The game", I would just write "Go"; this is my only
    stylistic comment.
    --What is a "grid board"?

    A board that is a grid or has a grid on it (seriously, this is self evident).

    --What does "it" refer to? The answer is unclear from what is written.

    "it" refers to the board.

    --The word "are" should be "is".
    --what does "fine" mean in this context? Do you really mean 81 is also fine?

    It means "are also ok", that is, it is acceptable.

    --Is 13x13 = 169 not fine? How is the reader supposed to interpret the symbol "x"?

    It means "by": 13x13 means 13 by 13. The notation has been around for a
    long time.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From S. Jasiek@21:1/5 to S. Jasiek on Sat Oct 14 00:13:14 2017
    S. Jasiek wrote:
    Robert Jasiek wrote:
    Bill wrote:
    "a piece of crap"
    Insulting comments convince nobody.


    I think that Bill made his point.

    Sam

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Bill@21:1/5 to Bates on Fri Oct 13 23:26:50 2017
    Bates wrote:
    Bill wrote:

    The second sentence says:

    "The game is played on a grid board. Typically it has 19x19
    intersections, but 9x9 are also fine."

    --In place of "The game", I would just write "Go"; this is my only
    stylistic comment.
    --What is a "grid board"?

    A board that is a grid or has a grid on it (seriously, this is self
    evident).

    --What does "it" refer to? The answer is unclear from what is written.

    "it" refers to the board.

    --The word "are" should be "is".
    --what does "fine" mean in this context? Do you really mean 81 is
    also fine?

    It means "are also ok", that is, it is acceptable.

    --Is 13x13 = 169 not fine? How is the reader supposed to interpret the
    symbol "x"?

    It means "by": 13x13 means 13 by 13. The notation has been around for
    a long time.


    Been around where, Mr. Bates?

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Robert Jasiek@21:1/5 to All on Sun Nov 12 05:02:26 2017
    Title: Rules FAQ
    Author: Robert Jasiek <jasiek@snafu.de>
    Frequency: monthly
    Last Update: 2017-10-13; First Day: 1999-04-12
    Distribution: rec.games.go
    Copyright: free non-commercial usage for promotion

    0 CONTENTS

    1 Purpose of this Paper
    2 Information for Beginners
    3 Important Concepts
    4 Particular Rules
    5 Troublesome Details
    6 Tournament Rules
    7 Links

    1 PURPOSE OF THIS PAPER

    This paper is a basic reference for important rules terms,
    rules, and tournament rules. Beginners should read
    especially Chapters 2 and 3, players Chapters 3 to 5,
    tournament players and organizers Chapter 6.

    2 INFORMATION FOR BEGINNERS
    2.1 What Must I Know as a Beginner?

    The game is played on a grid board. Typically it has 19x19
    intersections, but 9x9 are also fine. Two players compete.
    The first player uses black stones, the other white.

    The players alternate. A player may play or pass. Playing
    is putting one's own stone on an empty intersection and
    removing any surrounded opposing stones. To avoid
    cycles, a play may not recreate any prior configuration of
    all stones on the board.

    Two successive passes end the game. Then the player with
    more intersections wins. Intersections are his if only his
    stones occupy or surround them.

    2.2 Which Rules do I Need as a Beginner?

    You can play with short rules as in 2.1. Other rules may
    be different, but the game is the same, i. e. strategy,
    tactics, and the score do not change. Extremely rare
    exceptions confirm this rule.

    The winner can be determined by area or by territory.
    Either includes empty intersections surrounded only by own
    stones. While area adds intersections occupied by own
    stones, territory adds opposing prisoners instead.

    All rules, except short rules, have further phases after
    alternation and before scoring. Towards a game end it is
    often clear which stones will be removed. The additional
    phases allow the players to agree on which stones shall be
    removed. Thereby final removals do not require alternation.

    Whether you score by area or by territory or whether you
    remove by alternation or by agreement should mainly depend
    on which rules are used by people you play with.

    2.3 Which Rules Should I Teach?

    One possibility is to use a board with 9x9 intersections,
    short rules as in 2.1, and count each player's score by
    using a finger to scan the board for his intersections.

    3 IMPORTANT CONCEPTS

    While strategy and tactics virtually remain the same,
    concepts vary in different rules. However, the following
    gives a comprehensive overview on standard terms.

    3.1 Stone, String

    The physical device that colours one intersection in a
    play is a STONE. Two intersections of the board are
    ADJACENT if they have a line but no intersection between
    them. Two intersections with either black, white, or no
    stones on them are CONNECTED if they are adjacent or if
    there is a chain of adjacent intersections of their type
    between them. A REGION consists of an intersection and
    any intersections connected to it. A black or white
    region is called a STRING.

    3.2 Surrounded

    An intersection of one colour is SURROUNDED by another
    colour if each leaving path reaches the other colour first
    after the one colour. Hereby it can only be surrounded
    black by white, white by black, empty by black, or empty
    by white. A region can be surrounded. For strings there is
    an alternative notion of no liberty (or breath). A LIBERTY
    of a string is an empty intersection adjacent to it. Thus
    a string is surrounded if and only if it has no liberty.

    3.3 Removal, Suicide

    A removal empties the intersections of surrounded stones
    if there are any. Hereby removal of opposing stones is
    executed first, if necessary. Rules may either require or
    forbid removal of own stones. This is called suicide or no
    suicide. In practice, suicide might be used for so called ko
    fights or in capturing races.

    3.4 Capture, Prisoner

    Rules that score territory call a removal a capture
    because all removed stones are seriously kept as prisoners.

    3.5 Move, Play, Pass

    The players have alternate turns. On each turn a player makes
    a move that is either a play or a pass. A play places one's
    own stone on an empty intersection. It can then include
    removal of surrounded stones, if any. A pass merely continues
    alternation by giving the opponent the next turn.

    3.6 Compensation

    The first move advantage by black can be compensated by
    compensation points (komi) that are added to the white score
    after the game end. Komi can be adjusted by 0.5 to avoid
    ties. Today integer values for komi for 19x19 boards
    typically range between 5 and 7. For 13x13 boards one should
    use 8, for 9x9 boards 6; however, there is no real consensus
    for small board komi values yet. -
    A weaker player (black) can get the right to place an agreed
    number of compensation stones (handicap) before white's first
    play. Rules may allow free or fixed handicap. Free handicap
    does not apply any restriction. Fixed handicap requires
    traditional placement on set intersections.

    3.7 Phases

    Normally, a game consists of the phases alternation,
    agreement, scoring. A game stop is between alternation and
    agreement, the game end is between agreement and scoring,
    and after scoring both players accept the counted score as
    the result. The main part of the game is the alternation
    phase. Special rules are invoked after it. Typically, two
    successive passes in alternation are the game stop and start
    the agreement phase. In it the players may agree on strings
    to be removed. If they agree, then they remove those strings
    from the board; this ends the game. Sometimes they might
    disagree, then no strings are removed but alternation is
    resumed as if the last game stop did not occur.

    3.8 Recreation

    The position is the pattern of black and white stones on the
    board. Without extra rule a position might be repeated
    infinitely. The easiest rule to prohibit this says: A play
    may not recreate a position. This refers to positions after
    completion of plays, i.e. after possible removals. The rule
    is called "superko". -
    Some rules use concepts different from superko. They combine
    a "2-play rule" with a "long cycle rule". The first says:
    Two successive plays may not recreate a position. The second
    says: If a position is recreated after more than two moves,
    then the game ends either immediately or, as a variant, as
    soon as the players agree, with the result "without result".
    In practice the 2-play rule is sufficient for almost all
    cases. It handles the relevant standard pattern of two
    adjacent intersections. For superko this is just a special
    application.

    3.9 Scoring

    The score is the result after the game end as defined by
    the rules. There are two different scoring methods: area
    scoring and territory scoring. Rules use one of them. Both
    give the same result in almost all cases and both evaluate
    the difference of the black and the white scores. A player's
    AREA score is the sum of intersections with own stones and
    of empty intersections surrounded only by own stones. Simply
    speaking, a player's TERRITORY score is the sum of empty
    intersections surrounded only by own stones and of prisoners
    of opposing colour. With both scoring methods empty
    intersections that are not surrounded by either black or
    white are neutral.

    3.10 Counting

    A score must be determined by some mechanical procedure in
    practice; this is called counting. There are various methods.
    Some rules prescribe one. A possible method is to use one's
    finger to count point by point. Other methods rearrange a lot
    of stones on the board.

    4 PARTICULAR RULES

    Rules vary extremely. However, in practice they often give
    the same result.

    4.1 Short Rules

    Examples of short rules are the Simple Rules or the
    Tromp-Taylor rules. They have no game stop and no agreement.
    Both are superfluous since necessary removals may already be
    performed in the alternation. Two successive passes end the
    game that is scored then. Short rules use area scoring,
    superko, and suicide. Further settings are left for
    tournament rules.

    4.2 American Rules

    These are used by the American Go Association. They use
    situational superko, no suicide, and 7.5 komi. They permit
    free or fixed handicap. Their most remarkable feature is to
    allow one of area scoring or territory scoring. Herefore
    pass stones (one prisoner compensates each pass) and white
    moving last always ensure the same result, regardless of the
    applied scoring method.

    4.3 Chinese Rules

    These are used in continental China and sometimes in other
    countries. Area scoring and no suicide are used.

    4.3.1 Official Chinese Rules

    In practice, ko rules roughly amount to a 2-play rule and a
    long cycle rule. The mentioned superko is overridden. The
    counting is a sophisticated half counting, where empty
    intersections and then after rearrangements stones of one
    colour are added to be compared with half the non-neutral
    intersections. The komi as a half komi is 3.75. In full
    counting, counts and komi would be twice as big.

    4.3.2 Simplified Chinese Rules

    Positional superko is used. A counting method is not
    prescribed. The full komi should be 7.5.

    4.4 Japanese Rules

    The differences mainly affect handling of late game phases
    but often do not alter scores. Japanese rules use some
    traditional territory scoring that attempts to exclude so
    called sekis. No suicide applies. The core of the ko rules
    is a 2-play rule and a long cycle rule. Typically, komi is
    6.5. Fixed handicap should be used. The counting is a
    sophisticated rearrangement of empty intersections and
    filling-in of prisoners.

    4.4.1 Game Finishing Process

    A game finishes with the following process: 1) So called
    dame (neutral points) and defensive moves (necessary
    connections etc. due to occupied dame) are filled.
    2) The hypothetical analysis, which presumes perfect play,
    determines so called life or death of each string and the
    scoring intersections. 3) Without making any approach moves,
    dead stones are removed from scoring intersections and added
    to the prisoners. 4) The score is counted. (2) and (3) do not
    allow to play out life and death since actually filling
    intersections costs points in Japanese rules.

    4.4.2 Official Japanese Rules

    There are the Japanese 1989 Rules, which are used in Japan
    and elsewhere, and the World Amateur Go Championships Rules,
    which are used in some particular tournaments. Korean rules
    are similar to Japanese rules but have a very different text
    and differ in rare positions. Official Japanese rules are
    very incomplete and have messy late game phases. E.g., the
    Japanese 1989 Rules allow filling of dame during alternation,
    after it, or both and have a so called ko-pass-rule for the
    hypothetical analysis. Now professional Japanese rules are
    explained precisely by a rules expert's interpretation called
    "the Japanese 2003 Rules".

    4.4.3 Simplified Japanese Rules

    As a recent invention, they are not used yet. They are
    complete and have clear late game phases. Filling of dame is
    done during alternation.

    4.4.4 Verbal Japanese Rules

    They are used for informal games in many countries and
    undefined, except that the game finishing process is used.
    In a tournament without any official rules of play, disputes
    are not solved due to the rules but with a referee.

    4.5 Ing Rules

    Ing rules use area scoring, suicide, 8 komi with black
    winning ties, and free handicap.

    4.5.1 Official Ing Rules

    The ko rules are a mess but somehow resemble superko.
    Details could fill books. The late game phases are specified
    insufficiently. The peculiar counting method requires 180
    stones of each colour throughout the game, fills any stones
    on the board after the game end, and leaves exactly one
    empty intersection, which determines the winner. The
    official rules are used in professional Taiwanese and some
    sponsored tournaments. Taiwanese amateurs have their own
    rules.

    4.5.2 Simplified Ing Rules

    Positional superko is used. A counting method is not
    prescribed. The late game phases are specified clearly. The
    simplified rules are used in EGF tournaments that are said
    to use Ing rules.

    4.6 New Zealand Rules

    Area scoring, suicide, situational superko, 7 komi, and free
    handicap are used.

    4.7 Go Server Rules

    Every go server has its own and often complicated rules, if
    any, so they cannot be given in detail here. Concerning
    "IGS rules", territory scoring, no suicide, a 2-play rule,
    fixed handicap, three game stopping passes, and captures in
    an agreement phase are used. Details about agreements and
    long cycles are not specified and lead to adjourned games in
    case of doubt. Komi is suggested but may be altered. Counting
    is automatic. "Yahoo" has territory scoring, no suicide, a
    2-play rule, two game stopping passes; long cycles and
    disagreements are not handled properly. On "email servers"
    players must agree on any rules. -
    Typically territory scoring on a go server means that neither
    points in any sekis are excluded nor pass stones are used.
    Thus while the Japanese seki exception is abandoned,
    disagreements about removals may lead to games without result
    since playing out can cost points.

    4.8 International Rules

    The international mailing list go-rules has proposed
    international rules, however, none are adopted yet. The core
    rules of play shall be clear, complete, and correct.
    Currently alternative texts are offered for suicide,
    recreation, and scoring. Especially unification of scoring
    methods is advocated.

    4.9 EGF Rules

    The EGF uses the Simplified Ing Rules with 8 komi (black
    wins ties) in Ing sponsored tournaments and the Nihon Kiin
    1989 Rules with 6.5 komi in Japanese/Korean sponsored
    tournaments. If significantly the European Go Championship
    has both kinds of sponsors, then boards 1-16 use the Nihon
    Kiin 1989 Rules and boards 17+ the Simplified Ing Rules.
    However, time settings depend on ranks.

    5 TROUBLESOME DETAILS

    5.1 Colour Choice

    In even games typically the colours are randomly chosen. In
    handicap games black receives the handicap stones. -
    A manual method for randomly choosing colours is called
    nigiri. The older player hides a number of white stones
    taken from the bowl, the opponent takes one or two black
    stones to guess the parity, and the parity of the number of
    white stones is revealed. If the opponent guesses right,
    then he takes black, else he takes white.

    5.2 Pass Stones

    Some rules use pass stones. A passing player adds one own
    stone to the prisoners. As a consequence, captures before
    the game end can be resolved in alternation without any loss
    because any not answered approach move is compensated by one
    pass stone. With traditional territory scoring that uses no
    pass stones definition problems arise due to this missing
    option. Modern territory scoring or equivalence scoring use
    pass stones.

    5.3 Equivalence

    Area scoring and territory scoring are close because either
    intersections occupied by own stones or opposing prisoners
    are used. Essentially, every prisoner is a stone removed
    from some intersection. For area it scores one point less
    for the stone's player while for territory it scores one
    point more for his opponent. This is equal. Exact equality
    for the entire game must also consider passes by using pass
    stones and an equal number of moves by requiring white to
    pass last. This is done by equivalence scoring.

    5.4 Meaning of Agreement Removals

    Removals in an agreement phase under area scoring are fair
    because they may as well occur in alternation. Removing a
    stone due to agreement includes its then empty intersection
    and all adjacent empty intersections in the score. Removing
    a stone by means of alternation includes its then empty
    intersection and all adjacent newly occupied intersections
    in the score. -
    With traditional territory scoring this is not possible
    since stones on the board do not score. Thus final captures
    must occur after the game end due to attempted definitions
    in the rules.

    5.5 Practical Scoring Differences

    Since area scoring and modern territory scoring using pass
    stones are equal, correct play is the same for both. Apart
    from Japanese rules exceptions like not scoring empty
    intersections especially in asymmetrical coexistences or
    like a pass-for-ko-rule, traditional territory scoring can
    make a different winner in practically ca. every 10000th
    even game. This is so rare because of a parity feature
    combined with a scarcely odd number of intersections that
    are in coexistences but do not score for area at the game
    end. With area scoring a komi change from 1.5, 3.5, 5.5, ...
    to 2.5, 4.5, 6.5, ... almost always would not change the
    winner. So altough occupying the last empty intersections
    that would otherwise not score just before a game stop gains
    one point each, alternately doing so leaves a total
    advantage of at most one point. Due to the parity feature
    the player to get it is predetermined when this occupation
    starts. More importantly, one final ko is worth 1 point under
    traditional territory scoring but 2 or rarely 4 points under
    area scoring. Rare one-sided points in coexistences provide
    only area. Other practical differences are even rarer. Cute
    players include the stones in their endgame value counts
    during the middle of an area scoring game.

    5.6 Stone Scoring

    In ancient times stone scoring was popular. Only stones on
    the board are scored. Thus empty intersections surrounded by
    own stones are filled until necessary so called eyes remain.
    Disconnected stones require more eyes in total, the so
    called group tax.

    5.7 Old Ing Scoring

    Old Ing rules allowed fractional scores by assigning points
    to neutral empty regions due to the percentage of black and
    white stones surrounding every region.

    5.8 Primitive Rules

    They do not have passes. Alternation ends when a player
    loses due to no legal play. Games can be extremely long and
    include special strategies, so called pass fights. Primitive
    rules (also called no pass rules or Conway rules) can be
    useful in mathematics.

    5.9 Tradition

    Historically, exceptions arose, which some like as such
    especially together with Japanese style rules. So called
    sekis are excluded from the score. Special positions, termed
    precedents, have special rules. Modern Japanese rules have
    generalized a lot of them by a pass-for-ko-rule. After the
    game stop or after the game end and particularly in
    hypothetical play a stone captured in a possible 2-play cycle
    may not be recaptured unless before a pass is made that
    specifies the particular 2-play cycle.

    5.10 Positional / Situational Superko

    Positional superko prohibits a play that recreates a position.
    Situational superko refers to the situation, i.e. to the
    position together with the right to move. So a play is
    prohibited if it recreates a position while the same player
    has the right to move. In practice the differences are
    extremely rare.

    5.11 Handicap Recompensation

    With area scoring handicap stones beyond the first provide
    a potential extra area of one point per handicap stone. Komi
    for white may consider this. Recompensation, H-1 points for H
    handicap stones, is virtually only used together with
    American rules.

    5.12 Mathematics

    Go is a complete information game, i.e. at every move each
    player knows the entire game situation. Hence theoretically
    an algorithm could determine perfect play. However, due to
    the complexity of the game with N intersections, for which
    it is provably impossible to devise a polynomial time
    solution, perfect play or ideal komi are unknown. What one
    does know is that in a game without komi the first player wins
    or ties and that perfect play is independent of set komi. Many
    other propositions have been discovered, some of which
    describe the relation between area and territory scoring, solve
    tiny endgame positions or cyclical behaviour. -
    Go is a very complex game! According to John Tromp, the number
    of legal positions is:

    208168199381979984699478633344862770286522453884530548425 639456820927419612738015378525648451698519643907259916015 628128546089888314427129715319317557736620397247064840935

    For positional superko, no passes, and no resignation, the
    number of possible games is smaller than N**L(N) because L(N)
    also restricts the maximal number of moves per game and there
    are at most N possible intersections per move. (The sign ** is
    a text file notation for "to the power".) -
    Extremely modest estimates look like 10**N, which is based on
    an assumption of 10 reasonable intersections per move. A
    popular estimate for 19x19 go is 10**761, which must have
    originated from a typo and should be 10**361, if at all...
    These types of estimates are so popular because humans cannot
    even imagine the suggested number of atoms in the universe,
    10**80. For comparison, 3**361 is ca. 10**172.

    6 TOURNAMENT RULES

    6.1 Special Game Ends

    If the score considering the komi is zero, then the game is a
    tie and should be treated as 0.5 won games for each. Special
    rules or undue behaviour like sincere lateness might result
    in a referee declaring a win by forfeit, 0:0, or 1:1,
    whichever is most appropriate.

    6.2 Tournament Systems

    A tournament might consist of several stages, of which each
    has a seed and a system. A seed appropriately restricts
    participation, e.g. due to qualification. The most important
    systems are match, league, knockout, Swiss, McMahon. There
    are many others and hybrids. A system must fit the aims of a
    tournament. A sufficient number of rounds, a proper seed,
    and colour variation ensure a fair determination of the best
    player. -
    A match takes place between two players that either play a
    set number of games to see who wins more or a maximal number
    of games to see who wins a predetermined number of games
    first. In a league a small, usually even number of players
    performs a round-robin tournament, so that in each round all
    players play and every two players play against each other,
    one game e.g. A knockout preferably starts with a number of
    players that is a power of two. Losing players are eliminated,
    winning players continue until the winner remains. -
    In a Swiss system before each round each player's achieved
    number of wins is used to pair players with equal numbers as
    far as possible. So all players play all rounds and some time
    the best player will emerge. However, with greatly varying
    strengths too many rounds would be needed. So Swiss is only
    useful for particular events or handicap tournaments.
    McMahon is the refinement of Swiss. Before the start of the
    tournament all players are classified in rank groups, with
    ranks R from 0 to T. This means that one assumes a preceding
    Swiss tournament where every player has already won R games.
    Then in the McMahon tournament the strongest players, who
    deserve the rank T, compete for the top places. In practice,
    one uses a bar B, that is 1 or 2 ranks below T, so that all
    ranks above B are contracted to B and also players slightly
    weaker than the top players get their chance. All players in
    a McMahon play roughly equal opponents; if they win or lose,
    then the opponents will be stronger or weaker.

    6.3 Tie Breakers

    Tie breakers can refine pairings or results. Typically the
    first criterion is the number of wins (or McMahon points);
    all further criteria, if any, are tie breakers. They attempt
    a refinement where a low number of rounds and a tournament
    system do not guarantee sufficient distinction between
    players' achievements. However, they must be applied with
    care since they are only marginally better than coin tossing.
    Examples of tie breakers are direct comparison, which
    acknowledges the winner of a game between two players in
    question, and SOS, which is the Sum of Opponents' Scores. -
    The possible degree of quality of tie breakers is subject to
    discussion. It depends on tournament system, whether only the
    top or all players shall be distinguished, and other factors.
    An alternative to the usage of tie breakers for the final
    results ordering is issuing shared places for all players
    with the same number of wins (or McMahon points). - One must
    fairly assign tie breaker points for opponents missing in
    some round; enforcing participation is preferable especially
    for top players.

    6.4 Pairing

    Pairings must be fair, precise, and consider prior
    achievements during a tournament. One should consider colour
    balance and no pair twice, one might also aim at avoiding a
    pair of players from the same club or country, depending on
    a tournament's intentions. Pairings might be done manually
    in small tournaments; for most tournaments pairing programs
    should be used. These can create fair pairings convincingly,
    some even watch global balance.

    6.5 Thinking Times

    The age of killing each other by greater endurance has gone.
    Clocks are used to count each player's remaining thinking
    time. Typically, every game has a basic time and overtime
    periods. Exceeding a time limit loses a game. Basic time
    might be 9 hours for a professional top game, 10 minutes for
    a lightning game, or something in between that fits a
    tournament's intentions. An overtime period requires a fixed
    number of moves within a predetermined period, e.g. 1 move
    within 60 seconds. A move is finished by pressing the clock.
    - Many variants or other time systems exist, e.g., increasing
    numbers of moves in further overtime periods, penalty points
    for entering further periods, full usage of every overtime
    period, thinking time working like an hour glass, etc.

    6.6 Tournament Rules

    Every tournament uses an announced set of tournament rules.
    They especially specify the used set for the core rules of
    play, the tournament system, tie breakers, the pairing
    method, the winning criteria, compensation methods,
    thinking times, direction, jurisdiction, adjournment
    methods, penalities for being late, etc. Tournament rules
    often deal with details. Not everything can be predicted, so
    a sportsmanlike spirit is mentioned. Finally, it should be
    clear which of several rule sets takes precedence.

    6.7 Tournament Organization

    A regional tournament can be organized by a club. Big events
    can be held at the request of an association or federation,
    who also supervise. A tournament organization is responsible
    for providing a venue and playing material. It must be
    distinguished from the tournament director and his assistant
    directors, who perform the particular tasks of pairing,
    collecting results, and ensuring smooth running. Shared
    power furthermore demands independent referees.

    6.8 Jurisdiction

    Before the start of a tournament valid instances of a
    jurisdiction as well as the persons to be referees must be
    clear. Typically, for a tournament itself there is one
    referee as the first instance and a body of three referees
    as the second instance. For very peculiar cases a federation
    could have a third and final instance. Some tournament rules
    replace the second instance by a single person, called chief
    referee; to avoid confusion he ought not to judge as the
    first instance. Players should respect the referees' tough
    job of mediation or decision; referees should seriously
    enforce the rules.

    6.9 Prizes

    The first places of a tournament invoke major prizes. E.g.
    the first, second, third places might get 3/6, 2/6, 1/6 of
    the available money. In a tournament with many weaker
    players it is a good idea to provide some prizes for all
    other players that win most rounds as well. While prizes can
    be money, books, trophies, etc., one should remember that
    money is most universally accepted and trophies serve the
    media better than the winners. -
    On a related topic, a side event lottery must give equal
    chances to all participants. This is only achieved by using
    one lot for each.

    7 Links

    Most rules information, links, short rules: http://home.snafu.de/jasiek/rules.html

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Robert Jasiek@21:1/5 to All on Tue Dec 12 08:01:14 2017
    Title: Rules FAQ
    Author: Robert Jasiek <jasiek@snafu.de>
    Frequency: monthly
    Last Update: 2017-10-13; First Day: 1999-04-12
    Distribution: rec.games.go
    Copyright: free non-commercial usage for promotion

    0 CONTENTS

    1 Purpose of this Paper
    2 Information for Beginners
    3 Important Concepts
    4 Particular Rules
    5 Troublesome Details
    6 Tournament Rules
    7 Links

    1 PURPOSE OF THIS PAPER

    This paper is a basic reference for important rules terms,
    rules, and tournament rules. Beginners should read
    especially Chapters 2 and 3, players Chapters 3 to 5,
    tournament players and organizers Chapter 6.

    2 INFORMATION FOR BEGINNERS
    2.1 What Must I Know as a Beginner?

    The game is played on a grid board. Typically it has 19x19
    intersections, but 9x9 are also fine. Two players compete.
    The first player uses black stones, the other white.

    The players alternate. A player may play or pass. Playing
    is putting one's own stone on an empty intersection and
    removing any surrounded opposing stones. To avoid
    cycles, a play may not recreate any prior configuration of
    all stones on the board.

    Two successive passes end the game. Then the player with
    more intersections wins. Intersections are his if only his
    stones occupy or surround them.

    2.2 Which Rules do I Need as a Beginner?

    You can play with short rules as in 2.1. Other rules may
    be different, but the game is the same, i. e. strategy,
    tactics, and the score do not change. Extremely rare
    exceptions confirm this rule.

    The winner can be determined by area or by territory.
    Either includes empty intersections surrounded only by own
    stones. While area adds intersections occupied by own
    stones, territory adds opposing prisoners instead.

    All rules, except short rules, have further phases after
    alternation and before scoring. Towards a game end it is
    often clear which stones will be removed. The additional
    phases allow the players to agree on which stones shall be
    removed. Thereby final removals do not require alternation.

    Whether you score by area or by territory or whether you
    remove by alternation or by agreement should mainly depend
    on which rules are used by people you play with.

    2.3 Which Rules Should I Teach?

    One possibility is to use a board with 9x9 intersections,
    short rules as in 2.1, and count each player's score by
    using a finger to scan the board for his intersections.

    3 IMPORTANT CONCEPTS

    While strategy and tactics virtually remain the same,
    concepts vary in different rules. However, the following
    gives a comprehensive overview on standard terms.

    3.1 Stone, String

    The physical device that colours one intersection in a
    play is a STONE. Two intersections of the board are
    ADJACENT if they have a line but no intersection between
    them. Two intersections with either black, white, or no
    stones on them are CONNECTED if they are adjacent or if
    there is a chain of adjacent intersections of their type
    between them. A REGION consists of an intersection and
    any intersections connected to it. A black or white
    region is called a STRING.

    3.2 Surrounded

    An intersection of one colour is SURROUNDED by another
    colour if each leaving path reaches the other colour first
    after the one colour. Hereby it can only be surrounded
    black by white, white by black, empty by black, or empty
    by white. A region can be surrounded. For strings there is
    an alternative notion of no liberty (or breath). A LIBERTY
    of a string is an empty intersection adjacent to it. Thus
    a string is surrounded if and only if it has no liberty.

    3.3 Removal, Suicide

    A removal empties the intersections of surrounded stones
    if there are any. Hereby removal of opposing stones is
    executed first, if necessary. Rules may either require or
    forbid removal of own stones. This is called suicide or no
    suicide. In practice, suicide might be used for so called ko
    fights or in capturing races.

    3.4 Capture, Prisoner

    Rules that score territory call a removal a capture
    because all removed stones are seriously kept as prisoners.

    3.5 Move, Play, Pass

    The players have alternate turns. On each turn a player makes
    a move that is either a play or a pass. A play places one's
    own stone on an empty intersection. It can then include
    removal of surrounded stones, if any. A pass merely continues
    alternation by giving the opponent the next turn.

    3.6 Compensation

    The first move advantage by black can be compensated by
    compensation points (komi) that are added to the white score
    after the game end. Komi can be adjusted by 0.5 to avoid
    ties. Today integer values for komi for 19x19 boards
    typically range between 5 and 7. For 13x13 boards one should
    use 8, for 9x9 boards 6; however, there is no real consensus
    for small board komi values yet. -
    A weaker player (black) can get the right to place an agreed
    number of compensation stones (handicap) before white's first
    play. Rules may allow free or fixed handicap. Free handicap
    does not apply any restriction. Fixed handicap requires
    traditional placement on set intersections.

    3.7 Phases

    Normally, a game consists of the phases alternation,
    agreement, scoring. A game stop is between alternation and
    agreement, the game end is between agreement and scoring,
    and after scoring both players accept the counted score as
    the result. The main part of the game is the alternation
    phase. Special rules are invoked after it. Typically, two
    successive passes in alternation are the game stop and start
    the agreement phase. In it the players may agree on strings
    to be removed. If they agree, then they remove those strings
    from the board; this ends the game. Sometimes they might
    disagree, then no strings are removed but alternation is
    resumed as if the last game stop did not occur.

    3.8 Recreation

    The position is the pattern of black and white stones on the
    board. Without extra rule a position might be repeated
    infinitely. The easiest rule to prohibit this says: A play
    may not recreate a position. This refers to positions after
    completion of plays, i.e. after possible removals. The rule
    is called "superko". -
    Some rules use concepts different from superko. They combine
    a "2-play rule" with a "long cycle rule". The first says:
    Two successive plays may not recreate a position. The second
    says: If a position is recreated after more than two moves,
    then the game ends either immediately or, as a variant, as
    soon as the players agree, with the result "without result".
    In practice the 2-play rule is sufficient for almost all
    cases. It handles the relevant standard pattern of two
    adjacent intersections. For superko this is just a special
    application.

    3.9 Scoring

    The score is the result after the game end as defined by
    the rules. There are two different scoring methods: area
    scoring and territory scoring. Rules use one of them. Both
    give the same result in almost all cases and both evaluate
    the difference of the black and the white scores. A player's
    AREA score is the sum of intersections with own stones and
    of empty intersections surrounded only by own stones. Simply
    speaking, a player's TERRITORY score is the sum of empty
    intersections surrounded only by own stones and of prisoners
    of opposing colour. With both scoring methods empty
    intersections that are not surrounded by either black or
    white are neutral.

    3.10 Counting

    A score must be determined by some mechanical procedure in
    practice; this is called counting. There are various methods.
    Some rules prescribe one. A possible method is to use one's
    finger to count point by point. Other methods rearrange a lot
    of stones on the board.

    4 PARTICULAR RULES

    Rules vary extremely. However, in practice they often give
    the same result.

    4.1 Short Rules

    Examples of short rules are the Simple Rules or the
    Tromp-Taylor rules. They have no game stop and no agreement.
    Both are superfluous since necessary removals may already be
    performed in the alternation. Two successive passes end the
    game that is scored then. Short rules use area scoring,
    superko, and suicide. Further settings are left for
    tournament rules.

    4.2 American Rules

    These are used by the American Go Association. They use
    situational superko, no suicide, and 7.5 komi. They permit
    free or fixed handicap. Their most remarkable feature is to
    allow one of area scoring or territory scoring. Herefore
    pass stones (one prisoner compensates each pass) and white
    moving last always ensure the same result, regardless of the
    applied scoring method.

    4.3 Chinese Rules

    These are used in continental China and sometimes in other
    countries. Area scoring and no suicide are used.

    4.3.1 Official Chinese Rules

    In practice, ko rules roughly amount to a 2-play rule and a
    long cycle rule. The mentioned superko is overridden. The
    counting is a sophisticated half counting, where empty
    intersections and then after rearrangements stones of one
    colour are added to be compared with half the non-neutral
    intersections. The komi as a half komi is 3.75. In full
    counting, counts and komi would be twice as big.

    4.3.2 Simplified Chinese Rules

    Positional superko is used. A counting method is not
    prescribed. The full komi should be 7.5.

    4.4 Japanese Rules

    The differences mainly affect handling of late game phases
    but often do not alter scores. Japanese rules use some
    traditional territory scoring that attempts to exclude so
    called sekis. No suicide applies. The core of the ko rules
    is a 2-play rule and a long cycle rule. Typically, komi is
    6.5. Fixed handicap should be used. The counting is a
    sophisticated rearrangement of empty intersections and
    filling-in of prisoners.

    4.4.1 Game Finishing Process

    A game finishes with the following process: 1) So called
    dame (neutral points) and defensive moves (necessary
    connections etc. due to occupied dame) are filled.
    2) The hypothetical analysis, which presumes perfect play,
    determines so called life or death of each string and the
    scoring intersections. 3) Without making any approach moves,
    dead stones are removed from scoring intersections and added
    to the prisoners. 4) The score is counted. (2) and (3) do not
    allow to play out life and death since actually filling
    intersections costs points in Japanese rules.

    4.4.2 Official Japanese Rules

    There are the Japanese 1989 Rules, which are used in Japan
    and elsewhere, and the World Amateur Go Championships Rules,
    which are used in some particular tournaments. Korean rules
    are similar to Japanese rules but have a very different text
    and differ in rare positions. Official Japanese rules are
    very incomplete and have messy late game phases. E.g., the
    Japanese 1989 Rules allow filling of dame during alternation,
    after it, or both and have a so called ko-pass-rule for the
    hypothetical analysis. Now professional Japanese rules are
    explained precisely by a rules expert's interpretation called
    "the Japanese 2003 Rules".

    4.4.3 Simplified Japanese Rules

    As a recent invention, they are not used yet. They are
    complete and have clear late game phases. Filling of dame is
    done during alternation.

    4.4.4 Verbal Japanese Rules

    They are used for informal games in many countries and
    undefined, except that the game finishing process is used.
    In a tournament without any official rules of play, disputes
    are not solved due to the rules but with a referee.

    4.5 Ing Rules

    Ing rules use area scoring, suicide, 8 komi with black
    winning ties, and free handicap.

    4.5.1 Official Ing Rules

    The ko rules are a mess but somehow resemble superko.
    Details could fill books. The late game phases are specified
    insufficiently. The peculiar counting method requires 180
    stones of each colour throughout the game, fills any stones
    on the board after the game end, and leaves exactly one
    empty intersection, which determines the winner. The
    official rules are used in professional Taiwanese and some
    sponsored tournaments. Taiwanese amateurs have their own
    rules.

    4.5.2 Simplified Ing Rules

    Positional superko is used. A counting method is not
    prescribed. The late game phases are specified clearly. The
    simplified rules are used in EGF tournaments that are said
    to use Ing rules.

    4.6 New Zealand Rules

    Area scoring, suicide, situational superko, 7 komi, and free
    handicap are used.

    4.7 Go Server Rules

    Every go server has its own and often complicated rules, if
    any, so they cannot be given in detail here. Concerning
    "IGS rules", territory scoring, no suicide, a 2-play rule,
    fixed handicap, three game stopping passes, and captures in
    an agreement phase are used. Details about agreements and
    long cycles are not specified and lead to adjourned games in
    case of doubt. Komi is suggested but may be altered. Counting
    is automatic. "Yahoo" has territory scoring, no suicide, a
    2-play rule, two game stopping passes; long cycles and
    disagreements are not handled properly. On "email servers"
    players must agree on any rules. -
    Typically territory scoring on a go server means that neither
    points in any sekis are excluded nor pass stones are used.
    Thus while the Japanese seki exception is abandoned,
    disagreements about removals may lead to games without result
    since playing out can cost points.

    4.8 International Rules

    The international mailing list go-rules has proposed
    international rules, however, none are adopted yet. The core
    rules of play shall be clear, complete, and correct.
    Currently alternative texts are offered for suicide,
    recreation, and scoring. Especially unification of scoring
    methods is advocated.

    4.9 EGF Rules

    The EGF uses the Simplified Ing Rules with 8 komi (black
    wins ties) in Ing sponsored tournaments and the Nihon Kiin
    1989 Rules with 6.5 komi in Japanese/Korean sponsored
    tournaments. If significantly the European Go Championship
    has both kinds of sponsors, then boards 1-16 use the Nihon
    Kiin 1989 Rules and boards 17+ the Simplified Ing Rules.
    However, time settings depend on ranks.

    5 TROUBLESOME DETAILS

    5.1 Colour Choice

    In even games typically the colours are randomly chosen. In
    handicap games black receives the handicap stones. -
    A manual method for randomly choosing colours is called
    nigiri. The older player hides a number of white stones
    taken from the bowl, the opponent takes one or two black
    stones to guess the parity, and the parity of the number of
    white stones is revealed. If the opponent guesses right,
    then he takes black, else he takes white.

    5.2 Pass Stones

    Some rules use pass stones. A passing player adds one own
    stone to the prisoners. As a consequence, captures before
    the game end can be resolved in alternation without any loss
    because any not answered approach move is compensated by one
    pass stone. With traditional territory scoring that uses no
    pass stones definition problems arise due to this missing
    option. Modern territory scoring or equivalence scoring use
    pass stones.

    5.3 Equivalence

    Area scoring and territory scoring are close because either
    intersections occupied by own stones or opposing prisoners
    are used. Essentially, every prisoner is a stone removed
    from some intersection. For area it scores one point less
    for the stone's player while for territory it scores one
    point more for his opponent. This is equal. Exact equality
    for the entire game must also consider passes by using pass
    stones and an equal number of moves by requiring white to
    pass last. This is done by equivalence scoring.

    5.4 Meaning of Agreement Removals

    Removals in an agreement phase under area scoring are fair
    because they may as well occur in alternation. Removing a
    stone due to agreement includes its then empty intersection
    and all adjacent empty intersections in the score. Removing
    a stone by means of alternation includes its then empty
    intersection and all adjacent newly occupied intersections
    in the score. -
    With traditional territory scoring this is not possible
    since stones on the board do not score. Thus final captures
    must occur after the game end due to attempted definitions
    in the rules.

    5.5 Practical Scoring Differences

    Since area scoring and modern territory scoring using pass
    stones are equal, correct play is the same for both. Apart
    from Japanese rules exceptions like not scoring empty
    intersections especially in asymmetrical coexistences or
    like a pass-for-ko-rule, traditional territory scoring can
    make a different winner in practically ca. every 10000th
    even game. This is so rare because of a parity feature
    combined with a scarcely odd number of intersections that
    are in coexistences but do not score for area at the game
    end. With area scoring a komi change from 1.5, 3.5, 5.5, ...
    to 2.5, 4.5, 6.5, ... almost always would not change the
    winner. So altough occupying the last empty intersections
    that would otherwise not score just before a game stop gains
    one point each, alternately doing so leaves a total
    advantage of at most one point. Due to the parity feature
    the player to get it is predetermined when this occupation
    starts. More importantly, one final ko is worth 1 point under
    traditional territory scoring but 2 or rarely 4 points under
    area scoring. Rare one-sided points in coexistences provide
    only area. Other practical differences are even rarer. Cute
    players include the stones in their endgame value counts
    during the middle of an area scoring game.

    5.6 Stone Scoring

    In ancient times stone scoring was popular. Only stones on
    the board are scored. Thus empty intersections surrounded by
    own stones are filled until necessary so called eyes remain.
    Disconnected stones require more eyes in total, the so
    called group tax.

    5.7 Old Ing Scoring

    Old Ing rules allowed fractional scores by assigning points
    to neutral empty regions due to the percentage of black and
    white stones surrounding every region.

    5.8 Primitive Rules

    They do not have passes. Alternation ends when a player
    loses due to no legal play. Games can be extremely long and
    include special strategies, so called pass fights. Primitive
    rules (also called no pass rules or Conway rules) can be
    useful in mathematics.

    5.9 Tradition

    Historically, exceptions arose, which some like as such
    especially together with Japanese style rules. So called
    sekis are excluded from the score. Special positions, termed
    precedents, have special rules. Modern Japanese rules have
    generalized a lot of them by a pass-for-ko-rule. After the
    game stop or after the game end and particularly in
    hypothetical play a stone captured in a possible 2-play cycle
    may not be recaptured unless before a pass is made that
    specifies the particular 2-play cycle.

    5.10 Positional / Situational Superko

    Positional superko prohibits a play that recreates a position.
    Situational superko refers to the situation, i.e. to the
    position together with the right to move. So a play is
    prohibited if it recreates a position while the same player
    has the right to move. In practice the differences are
    extremely rare.

    5.11 Handicap Recompensation

    With area scoring handicap stones beyond the first provide
    a potential extra area of one point per handicap stone. Komi
    for white may consider this. Recompensation, H-1 points for H
    handicap stones, is virtually only used together with
    American rules.

    5.12 Mathematics

    Go is a complete information game, i.e. at every move each
    player knows the entire game situation. Hence theoretically
    an algorithm could determine perfect play. However, due to
    the complexity of the game with N intersections, for which
    it is provably impossible to devise a polynomial time
    solution, perfect play or ideal komi are unknown. What one
    does know is that in a game without komi the first player wins
    or ties and that perfect play is independent of set komi. Many
    other propositions have been discovered, some of which
    describe the relation between area and territory scoring, solve
    tiny endgame positions or cyclical behaviour. -
    Go is a very complex game! According to John Tromp, the number
    of legal positions is:

    208168199381979984699478633344862770286522453884530548425 639456820927419612738015378525648451698519643907259916015 628128546089888314427129715319317557736620397247064840935

    For positional superko, no passes, and no resignation, the
    number of possible games is smaller than N**L(N) because L(N)
    also restricts the maximal number of moves per game and there
    are at most N possible intersections per move. (The sign ** is
    a text file notation for "to the power".) -
    Extremely modest estimates look like 10**N, which is based on
    an assumption of 10 reasonable intersections per move. A
    popular estimate for 19x19 go is 10**761, which must have
    originated from a typo and should be 10**361, if at all...
    These types of estimates are so popular because humans cannot
    even imagine the suggested number of atoms in the universe,
    10**80. For comparison, 3**361 is ca. 10**172.

    6 TOURNAMENT RULES

    6.1 Special Game Ends

    If the score considering the komi is zero, then the game is a
    tie and should be treated as 0.5 won games for each. Special
    rules or undue behaviour like sincere lateness might result
    in a referee declaring a win by forfeit, 0:0, or 1:1,
    whichever is most appropriate.

    6.2 Tournament Systems

    A tournament might consist of several stages, of which each
    has a seed and a system. A seed appropriately restricts
    participation, e.g. due to qualification. The most important
    systems are match, league, knockout, Swiss, McMahon. There
    are many others and hybrids. A system must fit the aims of a
    tournament. A sufficient number of rounds, a proper seed,
    and colour variation ensure a fair determination of the best
    player. -
    A match takes place between two players that either play a
    set number of games to see who wins more or a maximal number
    of games to see who wins a predetermined number of games
    first. In a league a small, usually even number of players
    performs a round-robin tournament, so that in each round all
    players play and every two players play against each other,
    one game e.g. A knockout preferably starts with a number of
    players that is a power of two. Losing players are eliminated,
    winning players continue until the winner remains. -
    In a Swiss system before each round each player's achieved
    number of wins is used to pair players with equal numbers as
    far as possible. So all players play all rounds and some time
    the best player will emerge. However, with greatly varying
    strengths too many rounds would be needed. So Swiss is only
    useful for particular events or handicap tournaments.
    McMahon is the refinement of Swiss. Before the start of the
    tournament all players are classified in rank groups, with
    ranks R from 0 to T. This means that one assumes a preceding
    Swiss tournament where every player has already won R games.
    Then in the McMahon tournament the strongest players, who
    deserve the rank T, compete for the top places. In practice,
    one uses a bar B, that is 1 or 2 ranks below T, so that all
    ranks above B are contracted to B and also players slightly
    weaker than the top players get their chance. All players in
    a McMahon play roughly equal opponents; if they win or lose,
    then the opponents will be stronger or weaker.

    6.3 Tie Breakers

    Tie breakers can refine pairings or results. Typically the
    first criterion is the number of wins (or McMahon points);
    all further criteria, if any, are tie breakers. They attempt
    a refinement where a low number of rounds and a tournament
    system do not guarantee sufficient distinction between
    players' achievements. However, they must be applied with
    care since they are only marginally better than coin tossing.
    Examples of tie breakers are direct comparison, which
    acknowledges the winner of a game between two players in
    question, and SOS, which is the Sum of Opponents' Scores. -
    The possible degree of quality of tie breakers is subject to
    discussion. It depends on tournament system, whether only the
    top or all players shall be distinguished, and other factors.
    An alternative to the usage of tie breakers for the final
    results ordering is issuing shared places for all players
    with the same number of wins (or McMahon points). - One must
    fairly assign tie breaker points for opponents missing in
    some round; enforcing participation is preferable especially
    for top players.

    6.4 Pairing

    Pairings must be fair, precise, and consider prior
    achievements during a tournament. One should consider colour
    balance and no pair twice, one might also aim at avoiding a
    pair of players from the same club or country, depending on
    a tournament's intentions. Pairings might be done manually
    in small tournaments; for most tournaments pairing programs
    should be used. These can create fair pairings convincingly,
    some even watch global balance.

    6.5 Thinking Times

    The age of killing each other by greater endurance has gone.
    Clocks are used to count each player's remaining thinking
    time. Typically, every game has a basic time and overtime
    periods. Exceeding a time limit loses a game. Basic time
    might be 9 hours for a professional top game, 10 minutes for
    a lightning game, or something in between that fits a
    tournament's intentions. An overtime period requires a fixed
    number of moves within a predetermined period, e.g. 1 move
    within 60 seconds. A move is finished by pressing the clock.
    - Many variants or other time systems exist, e.g., increasing
    numbers of moves in further overtime periods, penalty points
    for entering further periods, full usage of every overtime
    period, thinking time working like an hour glass, etc.

    6.6 Tournament Rules

    Every tournament uses an announced set of tournament rules.
    They especially specify the used set for the core rules of
    play, the tournament system, tie breakers, the pairing
    method, the winning criteria, compensation methods,
    thinking times, direction, jurisdiction, adjournment
    methods, penalities for being late, etc. Tournament rules
    often deal with details. Not everything can be predicted, so
    a sportsmanlike spirit is mentioned. Finally, it should be
    clear which of several rule sets takes precedence.

    6.7 Tournament Organization

    A regional tournament can be organized by a club. Big events
    can be held at the request of an association or federation,
    who also supervise. A tournament organization is responsible
    for providing a venue and playing material. It must be
    distinguished from the tournament director and his assistant
    directors, who perform the particular tasks of pairing,
    collecting results, and ensuring smooth running. Shared
    power furthermore demands independent referees.

    6.8 Jurisdiction

    Before the start of a tournament valid instances of a
    jurisdiction as well as the persons to be referees must be
    clear. Typically, for a tournament itself there is one
    referee as the first instance and a body of three referees
    as the second instance. For very peculiar cases a federation
    could have a third and final instance. Some tournament rules
    replace the second instance by a single person, called chief
    referee; to avoid confusion he ought not to judge as the
    first instance. Players should respect the referees' tough
    job of mediation or decision; referees should seriously
    enforce the rules.

    6.9 Prizes

    The first places of a tournament invoke major prizes. E.g.
    the first, second, third places might get 3/6, 2/6, 1/6 of
    the available money. In a tournament with many weaker
    players it is a good idea to provide some prizes for all
    other players that win most rounds as well. While prizes can
    be money, books, trophies, etc., one should remember that
    money is most universally accepted and trophies serve the
    media better than the winners. -
    On a related topic, a side event lottery must give equal
    chances to all participants. This is only achieved by using
    one lot for each.

    7 Links

    Most rules information, links, short rules: http://home.snafu.de/jasiek/rules.html

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Robert Jasiek@21:1/5 to All on Fri Jan 12 11:45:13 2018
    Title: Rules FAQ
    Author: Robert Jasiek <jasiek@snafu.de>
    Frequency: monthly
    Last Update: 2017-10-13; First Day: 1999-04-12
    Distribution: rec.games.go
    Copyright: free non-commercial usage for promotion

    0 CONTENTS

    1 Purpose of this Paper
    2 Information for Beginners
    3 Important Concepts
    4 Particular Rules
    5 Troublesome Details
    6 Tournament Rules
    7 Links

    1 PURPOSE OF THIS PAPER

    This paper is a basic reference for important rules terms,
    rules, and tournament rules. Beginners should read
    especially Chapters 2 and 3, players Chapters 3 to 5,
    tournament players and organizers Chapter 6.

    2 INFORMATION FOR BEGINNERS
    2.1 What Must I Know as a Beginner?

    The game is played on a grid board. Typically it has 19x19
    intersections, but 9x9 are also fine. Two players compete.
    The first player uses black stones, the other white.

    The players alternate. A player may play or pass. Playing
    is putting one's own stone on an empty intersection and
    removing any surrounded opposing stones. To avoid
    cycles, a play may not recreate any prior configuration of
    all stones on the board.

    Two successive passes end the game. Then the player with
    more intersections wins. Intersections are his if only his
    stones occupy or surround them.

    2.2 Which Rules do I Need as a Beginner?

    You can play with short rules as in 2.1. Other rules may
    be different, but the game is the same, i. e. strategy,
    tactics, and the score do not change. Extremely rare
    exceptions confirm this rule.

    The winner can be determined by area or by territory.
    Either includes empty intersections surrounded only by own
    stones. While area adds intersections occupied by own
    stones, territory adds opposing prisoners instead.

    All rules, except short rules, have further phases after
    alternation and before scoring. Towards a game end it is
    often clear which stones will be removed. The additional
    phases allow the players to agree on which stones shall be
    removed. Thereby final removals do not require alternation.

    Whether you score by area or by territory or whether you
    remove by alternation or by agreement should mainly depend
    on which rules are used by people you play with.

    2.3 Which Rules Should I Teach?

    One possibility is to use a board with 9x9 intersections,
    short rules as in 2.1, and count each player's score by
    using a finger to scan the board for his intersections.

    3 IMPORTANT CONCEPTS

    While strategy and tactics virtually remain the same,
    concepts vary in different rules. However, the following
    gives a comprehensive overview on standard terms.

    3.1 Stone, String

    The physical device that colours one intersection in a
    play is a STONE. Two intersections of the board are
    ADJACENT if they have a line but no intersection between
    them. Two intersections with either black, white, or no
    stones on them are CONNECTED if they are adjacent or if
    there is a chain of adjacent intersections of their type
    between them. A REGION consists of an intersection and
    any intersections connected to it. A black or white
    region is called a STRING.

    3.2 Surrounded

    An intersection of one colour is SURROUNDED by another
    colour if each leaving path reaches the other colour first
    after the one colour. Hereby it can only be surrounded
    black by white, white by black, empty by black, or empty
    by white. A region can be surrounded. For strings there is
    an alternative notion of no liberty (or breath). A LIBERTY
    of a string is an empty intersection adjacent to it. Thus
    a string is surrounded if and only if it has no liberty.

    3.3 Removal, Suicide

    A removal empties the intersections of surrounded stones
    if there are any. Hereby removal of opposing stones is
    executed first, if necessary. Rules may either require or
    forbid removal of own stones. This is called suicide or no
    suicide. In practice, suicide might be used for so called ko
    fights or in capturing races.

    3.4 Capture, Prisoner

    Rules that score territory call a removal a capture
    because all removed stones are seriously kept as prisoners.

    3.5 Move, Play, Pass

    The players have alternate turns. On each turn a player makes
    a move that is either a play or a pass. A play places one's
    own stone on an empty intersection. It can then include
    removal of surrounded stones, if any. A pass merely continues
    alternation by giving the opponent the next turn.

    3.6 Compensation

    The first move advantage by black can be compensated by
    compensation points (komi) that are added to the white score
    after the game end. Komi can be adjusted by 0.5 to avoid
    ties. Today integer values for komi for 19x19 boards
    typically range between 5 and 7. For 13x13 boards one should
    use 8, for 9x9 boards 6; however, there is no real consensus
    for small board komi values yet. -
    A weaker player (black) can get the right to place an agreed
    number of compensation stones (handicap) before white's first
    play. Rules may allow free or fixed handicap. Free handicap
    does not apply any restriction. Fixed handicap requires
    traditional placement on set intersections.

    3.7 Phases

    Normally, a game consists of the phases alternation,
    agreement, scoring. A game stop is between alternation and
    agreement, the game end is between agreement and scoring,
    and after scoring both players accept the counted score as
    the result. The main part of the game is the alternation
    phase. Special rules are invoked after it. Typically, two
    successive passes in alternation are the game stop and start
    the agreement phase. In it the players may agree on strings
    to be removed. If they agree, then they remove those strings
    from the board; this ends the game. Sometimes they might
    disagree, then no strings are removed but alternation is
    resumed as if the last game stop did not occur.

    3.8 Recreation

    The position is the pattern of black and white stones on the
    board. Without extra rule a position might be repeated
    infinitely. The easiest rule to prohibit this says: A play
    may not recreate a position. This refers to positions after
    completion of plays, i.e. after possible removals. The rule
    is called "superko". -
    Some rules use concepts different from superko. They combine
    a "2-play rule" with a "long cycle rule". The first says:
    Two successive plays may not recreate a position. The second
    says: If a position is recreated after more than two moves,
    then the game ends either immediately or, as a variant, as
    soon as the players agree, with the result "without result".
    In practice the 2-play rule is sufficient for almost all
    cases. It handles the relevant standard pattern of two
    adjacent intersections. For superko this is just a special
    application.

    3.9 Scoring

    The score is the result after the game end as defined by
    the rules. There are two different scoring methods: area
    scoring and territory scoring. Rules use one of them. Both
    give the same result in almost all cases and both evaluate
    the difference of the black and the white scores. A player's
    AREA score is the sum of intersections with own stones and
    of empty intersections surrounded only by own stones. Simply
    speaking, a player's TERRITORY score is the sum of empty
    intersections surrounded only by own stones and of prisoners
    of opposing colour. With both scoring methods empty
    intersections that are not surrounded by either black or
    white are neutral.

    3.10 Counting

    A score must be determined by some mechanical procedure in
    practice; this is called counting. There are various methods.
    Some rules prescribe one. A possible method is to use one's
    finger to count point by point. Other methods rearrange a lot
    of stones on the board.

    4 PARTICULAR RULES

    Rules vary extremely. However, in practice they often give
    the same result.

    4.1 Short Rules

    Examples of short rules are the Simple Rules or the
    Tromp-Taylor rules. They have no game stop and no agreement.
    Both are superfluous since necessary removals may already be
    performed in the alternation. Two successive passes end the
    game that is scored then. Short rules use area scoring,
    superko, and suicide. Further settings are left for
    tournament rules.

    4.2 American Rules

    These are used by the American Go Association. They use
    situational superko, no suicide, and 7.5 komi. They permit
    free or fixed handicap. Their most remarkable feature is to
    allow one of area scoring or territory scoring. Herefore
    pass stones (one prisoner compensates each pass) and white
    moving last always ensure the same result, regardless of the
    applied scoring method.

    4.3 Chinese Rules

    These are used in continental China and sometimes in other
    countries. Area scoring and no suicide are used.

    4.3.1 Official Chinese Rules

    In practice, ko rules roughly amount to a 2-play rule and a
    long cycle rule. The mentioned superko is overridden. The
    counting is a sophisticated half counting, where empty
    intersections and then after rearrangements stones of one
    colour are added to be compared with half the non-neutral
    intersections. The komi as a half komi is 3.75. In full
    counting, counts and komi would be twice as big.

    4.3.2 Simplified Chinese Rules

    Positional superko is used. A counting method is not
    prescribed. The full komi should be 7.5.

    4.4 Japanese Rules

    The differences mainly affect handling of late game phases
    but often do not alter scores. Japanese rules use some
    traditional territory scoring that attempts to exclude so
    called sekis. No suicide applies. The core of the ko rules
    is a 2-play rule and a long cycle rule. Typically, komi is
    6.5. Fixed handicap should be used. The counting is a
    sophisticated rearrangement of empty intersections and
    filling-in of prisoners.

    4.4.1 Game Finishing Process

    A game finishes with the following process: 1) So called
    dame (neutral points) and defensive moves (necessary
    connections etc. due to occupied dame) are filled.
    2) The hypothetical analysis, which presumes perfect play,
    determines so called life or death of each string and the
    scoring intersections. 3) Without making any approach moves,
    dead stones are removed from scoring intersections and added
    to the prisoners. 4) The score is counted. (2) and (3) do not
    allow to play out life and death since actually filling
    intersections costs points in Japanese rules.

    4.4.2 Official Japanese Rules

    There are the Japanese 1989 Rules, which are used in Japan
    and elsewhere, and the World Amateur Go Championships Rules,
    which are used in some particular tournaments. Korean rules
    are similar to Japanese rules but have a very different text
    and differ in rare positions. Official Japanese rules are
    very incomplete and have messy late game phases. E.g., the
    Japanese 1989 Rules allow filling of dame during alternation,
    after it, or both and have a so called ko-pass-rule for the
    hypothetical analysis. Now professional Japanese rules are
    explained precisely by a rules expert's interpretation called
    "the Japanese 2003 Rules".

    4.4.3 Simplified Japanese Rules

    As a recent invention, they are not used yet. They are
    complete and have clear late game phases. Filling of dame is
    done during alternation.

    4.4.4 Verbal Japanese Rules

    They are used for informal games in many countries and
    undefined, except that the game finishing process is used.
    In a tournament without any official rules of play, disputes
    are not solved due to the rules but with a referee.

    4.5 Ing Rules

    Ing rules use area scoring, suicide, 8 komi with black
    winning ties, and free handicap.

    4.5.1 Official Ing Rules

    The ko rules are a mess but somehow resemble superko.
    Details could fill books. The late game phases are specified
    insufficiently. The peculiar counting method requires 180
    stones of each colour throughout the game, fills any stones
    on the board after the game end, and leaves exactly one
    empty intersection, which determines the winner. The
    official rules are used in professional Taiwanese and some
    sponsored tournaments. Taiwanese amateurs have their own
    rules.

    4.5.2 Simplified Ing Rules

    Positional superko is used. A counting method is not
    prescribed. The late game phases are specified clearly. The
    simplified rules are used in EGF tournaments that are said
    to use Ing rules.

    4.6 New Zealand Rules

    Area scoring, suicide, situational superko, 7 komi, and free
    handicap are used.

    4.7 Go Server Rules

    Every go server has its own and often complicated rules, if
    any, so they cannot be given in detail here. Concerning
    "IGS rules", territory scoring, no suicide, a 2-play rule,
    fixed handicap, three game stopping passes, and captures in
    an agreement phase are used. Details about agreements and
    long cycles are not specified and lead to adjourned games in
    case of doubt. Komi is suggested but may be altered. Counting
    is automatic. "Yahoo" has territory scoring, no suicide, a
    2-play rule, two game stopping passes; long cycles and
    disagreements are not handled properly. On "email servers"
    players must agree on any rules. -
    Typically territory scoring on a go server means that neither
    points in any sekis are excluded nor pass stones are used.
    Thus while the Japanese seki exception is abandoned,
    disagreements about removals may lead to games without result
    since playing out can cost points.

    4.8 International Rules

    The international mailing list go-rules has proposed
    international rules, however, none are adopted yet. The core
    rules of play shall be clear, complete, and correct.
    Currently alternative texts are offered for suicide,
    recreation, and scoring. Especially unification of scoring
    methods is advocated.

    4.9 EGF Rules

    The EGF uses the Simplified Ing Rules with 8 komi (black
    wins ties) in Ing sponsored tournaments and the Nihon Kiin
    1989 Rules with 6.5 komi in Japanese/Korean sponsored
    tournaments. If significantly the European Go Championship
    has both kinds of sponsors, then boards 1-16 use the Nihon
    Kiin 1989 Rules and boards 17+ the Simplified Ing Rules.
    However, time settings depend on ranks.

    5 TROUBLESOME DETAILS

    5.1 Colour Choice

    In even games typically the colours are randomly chosen. In
    handicap games black receives the handicap stones. -
    A manual method for randomly choosing colours is called
    nigiri. The older player hides a number of white stones
    taken from the bowl, the opponent takes one or two black
    stones to guess the parity, and the parity of the number of
    white stones is revealed. If the opponent guesses right,
    then he takes black, else he takes white.

    5.2 Pass Stones

    Some rules use pass stones. A passing player adds one own
    stone to the prisoners. As a consequence, captures before
    the game end can be resolved in alternation without any loss
    because any not answered approach move is compensated by one
    pass stone. With traditional territory scoring that uses no
    pass stones definition problems arise due to this missing
    option. Modern territory scoring or equivalence scoring use
    pass stones.

    5.3 Equivalence

    Area scoring and territory scoring are close because either
    intersections occupied by own stones or opposing prisoners
    are used. Essentially, every prisoner is a stone removed
    from some intersection. For area it scores one point less
    for the stone's player while for territory it scores one
    point more for his opponent. This is equal. Exact equality
    for the entire game must also consider passes by using pass
    stones and an equal number of moves by requiring white to
    pass last. This is done by equivalence scoring.

    5.4 Meaning of Agreement Removals

    Removals in an agreement phase under area scoring are fair
    because they may as well occur in alternation. Removing a
    stone due to agreement includes its then empty intersection
    and all adjacent empty intersections in the score. Removing
    a stone by means of alternation includes its then empty
    intersection and all adjacent newly occupied intersections
    in the score. -
    With traditional territory scoring this is not possible
    since stones on the board do not score. Thus final captures
    must occur after the game end due to attempted definitions
    in the rules.

    5.5 Practical Scoring Differences

    Since area scoring and modern territory scoring using pass
    stones are equal, correct play is the same for both. Apart
    from Japanese rules exceptions like not scoring empty
    intersections especially in asymmetrical coexistences or
    like a pass-for-ko-rule, traditional territory scoring can
    make a different winner in practically ca. every 10000th
    even game. This is so rare because of a parity feature
    combined with a scarcely odd number of intersections that
    are in coexistences but do not score for area at the game
    end. With area scoring a komi change from 1.5, 3.5, 5.5, ...
    to 2.5, 4.5, 6.5, ... almost always would not change the
    winner. So altough occupying the last empty intersections
    that would otherwise not score just before a game stop gains
    one point each, alternately doing so leaves a total
    advantage of at most one point. Due to the parity feature
    the player to get it is predetermined when this occupation
    starts. More importantly, one final ko is worth 1 point under
    traditional territory scoring but 2 or rarely 4 points under
    area scoring. Rare one-sided points in coexistences provide
    only area. Other practical differences are even rarer. Cute
    players include the stones in their endgame value counts
    during the middle of an area scoring game.

    5.6 Stone Scoring

    In ancient times stone scoring was popular. Only stones on
    the board are scored. Thus empty intersections surrounded by
    own stones are filled until necessary so called eyes remain.
    Disconnected stones require more eyes in total, the so
    called group tax.

    5.7 Old Ing Scoring

    Old Ing rules allowed fractional scores by assigning points
    to neutral empty regions due to the percentage of black and
    white stones surrounding every region.

    5.8 Primitive Rules

    They do not have passes. Alternation ends when a player
    loses due to no legal play. Games can be extremely long and
    include special strategies, so called pass fights. Primitive
    rules (also called no pass rules or Conway rules) can be
    useful in mathematics.

    5.9 Tradition

    Historically, exceptions arose, which some like as such
    especially together with Japanese style rules. So called
    sekis are excluded from the score. Special positions, termed
    precedents, have special rules. Modern Japanese rules have
    generalized a lot of them by a pass-for-ko-rule. After the
    game stop or after the game end and particularly in
    hypothetical play a stone captured in a possible 2-play cycle
    may not be recaptured unless before a pass is made that
    specifies the particular 2-play cycle.

    5.10 Positional / Situational Superko

    Positional superko prohibits a play that recreates a position.
    Situational superko refers to the situation, i.e. to the
    position together with the right to move. So a play is
    prohibited if it recreates a position while the same player
    has the right to move. In practice the differences are
    extremely rare.

    5.11 Handicap Recompensation

    With area scoring handicap stones beyond the first provide
    a potential extra area of one point per handicap stone. Komi
    for white may consider this. Recompensation, H-1 points for H
    handicap stones, is virtually only used together with
    American rules.

    5.12 Mathematics

    Go is a complete information game, i.e. at every move each
    player knows the entire game situation. Hence theoretically
    an algorithm could determine perfect play. However, due to
    the complexity of the game with N intersections, for which
    it is provably impossible to devise a polynomial time
    solution, perfect play or ideal komi are unknown. What one
    does know is that in a game without komi the first player wins
    or ties and that perfect play is independent of set komi. Many
    other propositions have been discovered, some of which
    describe the relation between area and territory scoring, solve
    tiny endgame positions or cyclical behaviour. -
    Go is a very complex game! According to John Tromp, the number
    of legal positions is:

    208168199381979984699478633344862770286522453884530548425 639456820927419612738015378525648451698519643907259916015 628128546089888314427129715319317557736620397247064840935

    For positional superko, no passes, and no resignation, the
    number of possible games is smaller than N**L(N) because L(N)
    also restricts the maximal number of moves per game and there
    are at most N possible intersections per move. (The sign ** is
    a text file notation for "to the power".) -
    Extremely modest estimates look like 10**N, which is based on
    an assumption of 10 reasonable intersections per move. A
    popular estimate for 19x19 go is 10**761, which must have
    originated from a typo and should be 10**361, if at all...
    These types of estimates are so popular because humans cannot
    even imagine the suggested number of atoms in the universe,
    10**80. For comparison, 3**361 is ca. 10**172.

    6 TOURNAMENT RULES

    6.1 Special Game Ends

    If the score considering the komi is zero, then the game is a
    tie and should be treated as 0.5 won games for each. Special
    rules or undue behaviour like sincere lateness might result
    in a referee declaring a win by forfeit, 0:0, or 1:1,
    whichever is most appropriate.

    6.2 Tournament Systems

    A tournament might consist of several stages, of which each
    has a seed and a system. A seed appropriately restricts
    participation, e.g. due to qualification. The most important
    systems are match, league, knockout, Swiss, McMahon. There
    are many others and hybrids. A system must fit the aims of a
    tournament. A sufficient number of rounds, a proper seed,
    and colour variation ensure a fair determination of the best
    player. -
    A match takes place between two players that either play a
    set number of games to see who wins more or a maximal number
    of games to see who wins a predetermined number of games
    first. In a league a small, usually even number of players
    performs a round-robin tournament, so that in each round all
    players play and every two players play against each other,
    one game e.g. A knockout preferably starts with a number of
    players that is a power of two. Losing players are eliminated,
    winning players continue until the winner remains. -
    In a Swiss system before each round each player's achieved
    number of wins is used to pair players with equal numbers as
    far as possible. So all players play all rounds and some time
    the best player will emerge. However, with greatly varying
    strengths too many rounds would be needed. So Swiss is only
    useful for particular events or handicap tournaments.
    McMahon is the refinement of Swiss. Before the start of the
    tournament all players are classified in rank groups, with
    ranks R from 0 to T. This means that one assumes a preceding
    Swiss tournament where every player has already won R games.
    Then in the McMahon tournament the strongest players, who
    deserve the rank T, compete for the top places. In practice,
    one uses a bar B, that is 1 or 2 ranks below T, so that all
    ranks above B are contracted to B and also players slightly
    weaker than the top players get their chance. All players in
    a McMahon play roughly equal opponents; if they win or lose,
    then the opponents will be stronger or weaker.

    6.3 Tie Breakers

    Tie breakers can refine pairings or results. Typically the
    first criterion is the number of wins (or McMahon points);
    all further criteria, if any, are tie breakers. They attempt
    a refinement where a low number of rounds and a tournament
    system do not guarantee sufficient distinction between
    players' achievements. However, they must be applied with
    care since they are only marginally better than coin tossing.
    Examples of tie breakers are direct comparison, which
    acknowledges the winner of a game between two players in
    question, and SOS, which is the Sum of Opponents' Scores. -
    The possible degree of quality of tie breakers is subject to
    discussion. It depends on tournament system, whether only the
    top or all players shall be distinguished, and other factors.
    An alternative to the usage of tie breakers for the final
    results ordering is issuing shared places for all players
    with the same number of wins (or McMahon points). - One must
    fairly assign tie breaker points for opponents missing in
    some round; enforcing participation is preferable especially
    for top players.

    6.4 Pairing

    Pairings must be fair, precise, and consider prior
    achievements during a tournament. One should consider colour
    balance and no pair twice, one might also aim at avoiding a
    pair of players from the same club or country, depending on
    a tournament's intentions. Pairings might be done manually
    in small tournaments; for most tournaments pairing programs
    should be used. These can create fair pairings convincingly,
    some even watch global balance.

    6.5 Thinking Times

    The age of killing each other by greater endurance has gone.
    Clocks are used to count each player's remaining thinking
    time. Typically, every game has a basic time and overtime
    periods. Exceeding a time limit loses a game. Basic time
    might be 9 hours for a professional top game, 10 minutes for
    a lightning game, or something in between that fits a
    tournament's intentions. An overtime period requires a fixed
    number of moves within a predetermined period, e.g. 1 move
    within 60 seconds. A move is finished by pressing the clock.
    - Many variants or other time systems exist, e.g., increasing
    numbers of moves in further overtime periods, penalty points
    for entering further periods, full usage of every overtime
    period, thinking time working like an hour glass, etc.

    6.6 Tournament Rules

    Every tournament uses an announced set of tournament rules.
    They especially specify the used set for the core rules of
    play, the tournament system, tie breakers, the pairing
    method, the winning criteria, compensation methods,
    thinking times, direction, jurisdiction, adjournment
    methods, penalities for being late, etc. Tournament rules
    often deal with details. Not everything can be predicted, so
    a sportsmanlike spirit is mentioned. Finally, it should be
    clear which of several rule sets takes precedence.

    6.7 Tournament Organization

    A regional tournament can be organized by a club. Big events
    can be held at the request of an association or federation,
    who also supervise. A tournament organization is responsible
    for providing a venue and playing material. It must be
    distinguished from the tournament director and his assistant
    directors, who perform the particular tasks of pairing,
    collecting results, and ensuring smooth running. Shared
    power furthermore demands independent referees.

    6.8 Jurisdiction

    Before the start of a tournament valid instances of a
    jurisdiction as well as the persons to be referees must be
    clear. Typically, for a tournament itself there is one
    referee as the first instance and a body of three referees
    as the second instance. For very peculiar cases a federation
    could have a third and final instance. Some tournament rules
    replace the second instance by a single person, called chief
    referee; to avoid confusion he ought not to judge as the
    first instance. Players should respect the referees' tough
    job of mediation or decision; referees should seriously
    enforce the rules.

    6.9 Prizes

    The first places of a tournament invoke major prizes. E.g.
    the first, second, third places might get 3/6, 2/6, 1/6 of
    the available money. In a tournament with many weaker
    players it is a good idea to provide some prizes for all
    other players that win most rounds as well. While prizes can
    be money, books, trophies, etc., one should remember that
    money is most universally accepted and trophies serve the
    media better than the winners. -
    On a related topic, a side event lottery must give equal
    chances to all participants. This is only achieved by using
    one lot for each.

    7 Links

    Most rules information, links, short rules: http://home.snafu.de/jasiek/rules.html

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Robert Jasiek@21:1/5 to All on Mon Feb 12 18:57:07 2018
    Title: Rules FAQ
    Author: Robert Jasiek <jasiek@snafu.de>
    Frequency: monthly
    Last Update: 2017-10-13; First Day: 1999-04-12
    Distribution: rec.games.go
    Copyright: free non-commercial usage for promotion

    0 CONTENTS

    1 Purpose of this Paper
    2 Information for Beginners
    3 Important Concepts
    4 Particular Rules
    5 Troublesome Details
    6 Tournament Rules
    7 Links

    1 PURPOSE OF THIS PAPER

    This paper is a basic reference for important rules terms,
    rules, and tournament rules. Beginners should read
    especially Chapters 2 and 3, players Chapters 3 to 5,
    tournament players and organizers Chapter 6.

    2 INFORMATION FOR BEGINNERS
    2.1 What Must I Know as a Beginner?

    The game is played on a grid board. Typically it has 19x19
    intersections, but 9x9 are also fine. Two players compete.
    The first player uses black stones, the other white.

    The players alternate. A player may play or pass. Playing
    is putting one's own stone on an empty intersection and
    removing any surrounded opposing stones. To avoid
    cycles, a play may not recreate any prior configuration of
    all stones on the board.

    Two successive passes end the game. Then the player with
    more intersections wins. Intersections are his if only his
    stones occupy or surround them.

    2.2 Which Rules do I Need as a Beginner?

    You can play with short rules as in 2.1. Other rules may
    be different, but the game is the same, i. e. strategy,
    tactics, and the score do not change. Extremely rare
    exceptions confirm this rule.

    The winner can be determined by area or by territory.
    Either includes empty intersections surrounded only by own
    stones. While area adds intersections occupied by own
    stones, territory adds opposing prisoners instead.

    All rules, except short rules, have further phases after
    alternation and before scoring. Towards a game end it is
    often clear which stones will be removed. The additional
    phases allow the players to agree on which stones shall be
    removed. Thereby final removals do not require alternation.

    Whether you score by area or by territory or whether you
    remove by alternation or by agreement should mainly depend
    on which rules are used by people you play with.

    2.3 Which Rules Should I Teach?

    One possibility is to use a board with 9x9 intersections,
    short rules as in 2.1, and count each player's score by
    using a finger to scan the board for his intersections.

    3 IMPORTANT CONCEPTS

    While strategy and tactics virtually remain the same,
    concepts vary in different rules. However, the following
    gives a comprehensive overview on standard terms.

    3.1 Stone, String

    The physical device that colours one intersection in a
    play is a STONE. Two intersections of the board are
    ADJACENT if they have a line but no intersection between
    them. Two intersections with either black, white, or no
    stones on them are CONNECTED if they are adjacent or if
    there is a chain of adjacent intersections of their type
    between them. A REGION consists of an intersection and
    any intersections connected to it. A black or white
    region is called a STRING.

    3.2 Surrounded

    An intersection of one colour is SURROUNDED by another
    colour if each leaving path reaches the other colour first
    after the one colour. Hereby it can only be surrounded
    black by white, white by black, empty by black, or empty
    by white. A region can be surrounded. For strings there is
    an alternative notion of no liberty (or breath). A LIBERTY
    of a string is an empty intersection adjacent to it. Thus
    a string is surrounded if and only if it has no liberty.

    3.3 Removal, Suicide

    A removal empties the intersections of surrounded stones
    if there are any. Hereby removal of opposing stones is
    executed first, if necessary. Rules may either require or
    forbid removal of own stones. This is called suicide or no
    suicide. In practice, suicide might be used for so called ko
    fights or in capturing races.

    3.4 Capture, Prisoner

    Rules that score territory call a removal a capture
    because all removed stones are seriously kept as prisoners.

    3.5 Move, Play, Pass

    The players have alternate turns. On each turn a player makes
    a move that is either a play or a pass. A play places one's
    own stone on an empty intersection. It can then include
    removal of surrounded stones, if any. A pass merely continues
    alternation by giving the opponent the next turn.

    3.6 Compensation

    The first move advantage by black can be compensated by
    compensation points (komi) that are added to the white score
    after the game end. Komi can be adjusted by 0.5 to avoid
    ties. Today integer values for komi for 19x19 boards
    typically range between 5 and 7. For 13x13 boards one should
    use 8, for 9x9 boards 6; however, there is no real consensus
    for small board komi values yet. -
    A weaker player (black) can get the right to place an agreed
    number of compensation stones (handicap) before white's first
    play. Rules may allow free or fixed handicap. Free handicap
    does not apply any restriction. Fixed handicap requires
    traditional placement on set intersections.

    3.7 Phases

    Normally, a game consists of the phases alternation,
    agreement, scoring. A game stop is between alternation and
    agreement, the game end is between agreement and scoring,
    and after scoring both players accept the counted score as
    the result. The main part of the game is the alternation
    phase. Special rules are invoked after it. Typically, two
    successive passes in alternation are the game stop and start
    the agreement phase. In it the players may agree on strings
    to be removed. If they agree, then they remove those strings
    from the board; this ends the game. Sometimes they might
    disagree, then no strings are removed but alternation is
    resumed as if the last game stop did not occur.

    3.8 Recreation

    The position is the pattern of black and white stones on the
    board. Without extra rule a position might be repeated
    infinitely. The easiest rule to prohibit this says: A play
    may not recreate a position. This refers to positions after
    completion of plays, i.e. after possible removals. The rule
    is called "superko". -
    Some rules use concepts different from superko. They combine
    a "2-play rule" with a "long cycle rule". The first says:
    Two successive plays may not recreate a position. The second
    says: If a position is recreated after more than two moves,
    then the game ends either immediately or, as a variant, as
    soon as the players agree, with the result "without result".
    In practice the 2-play rule is sufficient for almost all
    cases. It handles the relevant standard pattern of two
    adjacent intersections. For superko this is just a special
    application.

    3.9 Scoring

    The score is the result after the game end as defined by
    the rules. There are two different scoring methods: area
    scoring and territory scoring. Rules use one of them. Both
    give the same result in almost all cases and both evaluate
    the difference of the black and the white scores. A player's
    AREA score is the sum of intersections with own stones and
    of empty intersections surrounded only by own stones. Simply
    speaking, a player's TERRITORY score is the sum of empty
    intersections surrounded only by own stones and of prisoners
    of opposing colour. With both scoring methods empty
    intersections that are not surrounded by either black or
    white are neutral.

    3.10 Counting

    A score must be determined by some mechanical procedure in
    practice; this is called counting. There are various methods.
    Some rules prescribe one. A possible method is to use one's
    finger to count point by point. Other methods rearrange a lot
    of stones on the board.

    4 PARTICULAR RULES

    Rules vary extremely. However, in practice they often give
    the same result.

    4.1 Short Rules

    Examples of short rules are the Simple Rules or the
    Tromp-Taylor rules. They have no game stop and no agreement.
    Both are superfluous since necessary removals may already be
    performed in the alternation. Two successive passes end the
    game that is scored then. Short rules use area scoring,
    superko, and suicide. Further settings are left for
    tournament rules.

    4.2 American Rules

    These are used by the American Go Association. They use
    situational superko, no suicide, and 7.5 komi. They permit
    free or fixed handicap. Their most remarkable feature is to
    allow one of area scoring or territory scoring. Herefore
    pass stones (one prisoner compensates each pass) and white
    moving last always ensure the same result, regardless of the
    applied scoring method.

    4.3 Chinese Rules

    These are used in continental China and sometimes in other
    countries. Area scoring and no suicide are used.

    4.3.1 Official Chinese Rules

    In practice, ko rules roughly amount to a 2-play rule and a
    long cycle rule. The mentioned superko is overridden. The
    counting is a sophisticated half counting, where empty
    intersections and then after rearrangements stones of one
    colour are added to be compared with half the non-neutral
    intersections. The komi as a half komi is 3.75. In full
    counting, counts and komi would be twice as big.

    4.3.2 Simplified Chinese Rules

    Positional superko is used. A counting method is not
    prescribed. The full komi should be 7.5.

    4.4 Japanese Rules

    The differences mainly affect handling of late game phases
    but often do not alter scores. Japanese rules use some
    traditional territory scoring that attempts to exclude so
    called sekis. No suicide applies. The core of the ko rules
    is a 2-play rule and a long cycle rule. Typically, komi is
    6.5. Fixed handicap should be used. The counting is a
    sophisticated rearrangement of empty intersections and
    filling-in of prisoners.

    4.4.1 Game Finishing Process

    A game finishes with the following process: 1) So called
    dame (neutral points) and defensive moves (necessary
    connections etc. due to occupied dame) are filled.
    2) The hypothetical analysis, which presumes perfect play,
    determines so called life or death of each string and the
    scoring intersections. 3) Without making any approach moves,
    dead stones are removed from scoring intersections and added
    to the prisoners. 4) The score is counted. (2) and (3) do not
    allow to play out life and death since actually filling
    intersections costs points in Japanese rules.

    4.4.2 Official Japanese Rules

    There are the Japanese 1989 Rules, which are used in Japan
    and elsewhere, and the World Amateur Go Championships Rules,
    which are used in some particular tournaments. Korean rules
    are similar to Japanese rules but have a very different text
    and differ in rare positions. Official Japanese rules are
    very incomplete and have messy late game phases. E.g., the
    Japanese 1989 Rules allow filling of dame during alternation,
    after it, or both and have a so called ko-pass-rule for the
    hypothetical analysis. Now professional Japanese rules are
    explained precisely by a rules expert's interpretation called
    "the Japanese 2003 Rules".

    4.4.3 Simplified Japanese Rules

    As a recent invention, they are not used yet. They are
    complete and have clear late game phases. Filling of dame is
    done during alternation.

    4.4.4 Verbal Japanese Rules

    They are used for informal games in many countries and
    undefined, except that the game finishing process is used.
    In a tournament without any official rules of play, disputes
    are not solved due to the rules but with a referee.

    4.5 Ing Rules

    Ing rules use area scoring, suicide, 8 komi with black
    winning ties, and free handicap.

    4.5.1 Official Ing Rules

    The ko rules are a mess but somehow resemble superko.
    Details could fill books. The late game phases are specified
    insufficiently. The peculiar counting method requires 180
    stones of each colour throughout the game, fills any stones
    on the board after the game end, and leaves exactly one
    empty intersection, which determines the winner. The
    official rules are used in professional Taiwanese and some
    sponsored tournaments. Taiwanese amateurs have their own
    rules.

    4.5.2 Simplified Ing Rules

    Positional superko is used. A counting method is not
    prescribed. The late game phases are specified clearly. The
    simplified rules are used in EGF tournaments that are said
    to use Ing rules.

    4.6 New Zealand Rules

    Area scoring, suicide, situational superko, 7 komi, and free
    handicap are used.

    4.7 Go Server Rules

    Every go server has its own and often complicated rules, if
    any, so they cannot be given in detail here. Concerning
    "IGS rules", territory scoring, no suicide, a 2-play rule,
    fixed handicap, three game stopping passes, and captures in
    an agreement phase are used. Details about agreements and
    long cycles are not specified and lead to adjourned games in
    case of doubt. Komi is suggested but may be altered. Counting
    is automatic. "Yahoo" has territory scoring, no suicide, a
    2-play rule, two game stopping passes; long cycles and
    disagreements are not handled properly. On "email servers"
    players must agree on any rules. -
    Typically territory scoring on a go server means that neither
    points in any sekis are excluded nor pass stones are used.
    Thus while the Japanese seki exception is abandoned,
    disagreements about removals may lead to games without result
    since playing out can cost points.

    4.8 International Rules

    The international mailing list go-rules has proposed
    international rules, however, none are adopted yet. The core
    rules of play shall be clear, complete, and correct.
    Currently alternative texts are offered for suicide,
    recreation, and scoring. Especially unification of scoring
    methods is advocated.

    4.9 EGF Rules

    The EGF uses the Simplified Ing Rules with 8 komi (black
    wins ties) in Ing sponsored tournaments and the Nihon Kiin
    1989 Rules with 6.5 komi in Japanese/Korean sponsored
    tournaments. If significantly the European Go Championship
    has both kinds of sponsors, then boards 1-16 use the Nihon
    Kiin 1989 Rules and boards 17+ the Simplified Ing Rules.
    However, time settings depend on ranks.

    5 TROUBLESOME DETAILS

    5.1 Colour Choice

    In even games typically the colours are randomly chosen. In
    handicap games black receives the handicap stones. -
    A manual method for randomly choosing colours is called
    nigiri. The older player hides a number of white stones
    taken from the bowl, the opponent takes one or two black
    stones to guess the parity, and the parity of the number of
    white stones is revealed. If the opponent guesses right,
    then he takes black, else he takes white.

    5.2 Pass Stones

    Some rules use pass stones. A passing player adds one own
    stone to the prisoners. As a consequence, captures before
    the game end can be resolved in alternation without any loss
    because any not answered approach move is compensated by one
    pass stone. With traditional territory scoring that uses no
    pass stones definition problems arise due to this missing
    option. Modern territory scoring or equivalence scoring use
    pass stones.

    5.3 Equivalence

    Area scoring and territory scoring are close because either
    intersections occupied by own stones or opposing prisoners
    are used. Essentially, every prisoner is a stone removed
    from some intersection. For area it scores one point less
    for the stone's player while for territory it scores one
    point more for his opponent. This is equal. Exact equality
    for the entire game must also consider passes by using pass
    stones and an equal number of moves by requiring white to
    pass last. This is done by equivalence scoring.

    5.4 Meaning of Agreement Removals

    Removals in an agreement phase under area scoring are fair
    because they may as well occur in alternation. Removing a
    stone due to agreement includes its then empty intersection
    and all adjacent empty intersections in the score. Removing
    a stone by means of alternation includes its then empty
    intersection and all adjacent newly occupied intersections
    in the score. -
    With traditional territory scoring this is not possible
    since stones on the board do not score. Thus final captures
    must occur after the game end due to attempted definitions
    in the rules.

    5.5 Practical Scoring Differences

    Since area scoring and modern territory scoring using pass
    stones are equal, correct play is the same for both. Apart
    from Japanese rules exceptions like not scoring empty
    intersections especially in asymmetrical coexistences or
    like a pass-for-ko-rule, traditional territory scoring can
    make a different winner in practically ca. every 10000th
    even game. This is so rare because of a parity feature
    combined with a scarcely odd number of intersections that
    are in coexistences but do not score for area at the game
    end. With area scoring a komi change from 1.5, 3.5, 5.5, ...
    to 2.5, 4.5, 6.5, ... almost always would not change the
    winner. So altough occupying the last empty intersections
    that would otherwise not score just before a game stop gains
    one point each, alternately doing so leaves a total
    advantage of at most one point. Due to the parity feature
    the player to get it is predetermined when this occupation
    starts. More importantly, one final ko is worth 1 point under
    traditional territory scoring but 2 or rarely 4 points under
    area scoring. Rare one-sided points in coexistences provide
    only area. Other practical differences are even rarer. Cute
    players include the stones in their endgame value counts
    during the middle of an area scoring game.

    5.6 Stone Scoring

    In ancient times stone scoring was popular. Only stones on
    the board are scored. Thus empty intersections surrounded by
    own stones are filled until necessary so called eyes remain.
    Disconnected stones require more eyes in total, the so
    called group tax.

    5.7 Old Ing Scoring

    Old Ing rules allowed fractional scores by assigning points
    to neutral empty regions due to the percentage of black and
    white stones surrounding every region.

    5.8 Primitive Rules

    They do not have passes. Alternation ends when a player
    loses due to no legal play. Games can be extremely long and
    include special strategies, so called pass fights. Primitive
    rules (also called no pass rules or Conway rules) can be
    useful in mathematics.

    5.9 Tradition

    Historically, exceptions arose, which some like as such
    especially together with Japanese style rules. So called
    sekis are excluded from the score. Special positions, termed
    precedents, have special rules. Modern Japanese rules have
    generalized a lot of them by a pass-for-ko-rule. After the
    game stop or after the game end and particularly in
    hypothetical play a stone captured in a possible 2-play cycle
    may not be recaptured unless before a pass is made that
    specifies the particular 2-play cycle.

    5.10 Positional / Situational Superko

    Positional superko prohibits a play that recreates a position.
    Situational superko refers to the situation, i.e. to the
    position together with the right to move. So a play is
    prohibited if it recreates a position while the same player
    has the right to move. In practice the differences are
    extremely rare.

    5.11 Handicap Recompensation

    With area scoring handicap stones beyond the first provide
    a potential extra area of one point per handicap stone. Komi
    for white may consider this. Recompensation, H-1 points for H
    handicap stones, is virtually only used together with
    American rules.

    5.12 Mathematics

    Go is a complete information game, i.e. at every move each
    player knows the entire game situation. Hence theoretically
    an algorithm could determine perfect play. However, due to
    the complexity of the game with N intersections, for which
    it is provably impossible to devise a polynomial time
    solution, perfect play or ideal komi are unknown. What one
    does know is that in a game without komi the first player wins
    or ties and that perfect play is independent of set komi. Many
    other propositions have been discovered, some of which
    describe the relation between area and territory scoring, solve
    tiny endgame positions or cyclical behaviour. -
    Go is a very complex game! According to John Tromp, the number
    of legal positions is:

    208168199381979984699478633344862770286522453884530548425 639456820927419612738015378525648451698519643907259916015 628128546089888314427129715319317557736620397247064840935

    For positional superko, no passes, and no resignation, the
    number of possible games is smaller than N**L(N) because L(N)
    also restricts the maximal number of moves per game and there
    are at most N possible intersections per move. (The sign ** is
    a text file notation for "to the power".) -
    Extremely modest estimates look like 10**N, which is based on
    an assumption of 10 reasonable intersections per move. A
    popular estimate for 19x19 go is 10**761, which must have
    originated from a typo and should be 10**361, if at all...
    These types of estimates are so popular because humans cannot
    even imagine the suggested number of atoms in the universe,
    10**80. For comparison, 3**361 is ca. 10**172.

    6 TOURNAMENT RULES

    6.1 Special Game Ends

    If the score considering the komi is zero, then the game is a
    tie and should be treated as 0.5 won games for each. Special
    rules or undue behaviour like sincere lateness might result
    in a referee declaring a win by forfeit, 0:0, or 1:1,
    whichever is most appropriate.

    6.2 Tournament Systems

    A tournament might consist of several stages, of which each
    has a seed and a system. A seed appropriately restricts
    participation, e.g. due to qualification. The most important
    systems are match, league, knockout, Swiss, McMahon. There
    are many others and hybrids. A system must fit the aims of a
    tournament. A sufficient number of rounds, a proper seed,
    and colour variation ensure a fair determination of the best
    player. -
    A match takes place between two players that either play a
    set number of games to see who wins more or a maximal number
    of games to see who wins a predetermined number of games
    first. In a league a small, usually even number of players
    performs a round-robin tournament, so that in each round all
    players play and every two players play against each other,
    one game e.g. A knockout preferably starts with a number of
    players that is a power of two. Losing players are eliminated,
    winning players continue until the winner remains. -
    In a Swiss system before each round each player's achieved
    number of wins is used to pair players with equal numbers as
    far as possible. So all players play all rounds and some time
    the best player will emerge. However, with greatly varying
    strengths too many rounds would be needed. So Swiss is only
    useful for particular events or handicap tournaments.
    McMahon is the refinement of Swiss. Before the start of the
    tournament all players are classified in rank groups, with
    ranks R from 0 to T. This means that one assumes a preceding
    Swiss tournament where every player has already won R games.
    Then in the McMahon tournament the strongest players, who
    deserve the rank T, compete for the top places. In practice,
    one uses a bar B, that is 1 or 2 ranks below T, so that all
    ranks above B are contracted to B and also players slightly
    weaker than the top players get their chance. All players in
    a McMahon play roughly equal opponents; if they win or lose,
    then the opponents will be stronger or weaker.

    6.3 Tie Breakers

    Tie breakers can refine pairings or results. Typically the
    first criterion is the number of wins (or McMahon points);
    all further criteria, if any, are tie breakers. They attempt
    a refinement where a low number of rounds and a tournament
    system do not guarantee sufficient distinction between
    players' achievements. However, they must be applied with
    care since they are only marginally better than coin tossing.
    Examples of tie breakers are direct comparison, which
    acknowledges the winner of a game between two players in
    question, and SOS, which is the Sum of Opponents' Scores. -
    The possible degree of quality of tie breakers is subject to
    discussion. It depends on tournament system, whether only the
    top or all players shall be distinguished, and other factors.
    An alternative to the usage of tie breakers for the final
    results ordering is issuing shared places for all players
    with the same number of wins (or McMahon points). - One must
    fairly assign tie breaker points for opponents missing in
    some round; enforcing participation is preferable especially
    for top players.

    6.4 Pairing

    Pairings must be fair, precise, and consider prior
    achievements during a tournament. One should consider colour
    balance and no pair twice, one might also aim at avoiding a
    pair of players from the same club or country, depending on
    a tournament's intentions. Pairings might be done manually
    in small tournaments; for most tournaments pairing programs
    should be used. These can create fair pairings convincingly,
    some even watch global balance.

    6.5 Thinking Times

    The age of killing each other by greater endurance has gone.
    Clocks are used to count each player's remaining thinking
    time. Typically, every game has a basic time and overtime
    periods. Exceeding a time limit loses a game. Basic time
    might be 9 hours for a professional top game, 10 minutes for
    a lightning game, or something in between that fits a
    tournament's intentions. An overtime period requires a fixed
    number of moves within a predetermined period, e.g. 1 move
    within 60 seconds. A move is finished by pressing the clock.
    - Many variants or other time systems exist, e.g., increasing
    numbers of moves in further overtime periods, penalty points
    for entering further periods, full usage of every overtime
    period, thinking time working like an hour glass, etc.

    6.6 Tournament Rules

    Every tournament uses an announced set of tournament rules.
    They especially specify the used set for the core rules of
    play, the tournament system, tie breakers, the pairing
    method, the winning criteria, compensation methods,
    thinking times, direction, jurisdiction, adjournment
    methods, penalities for being late, etc. Tournament rules
    often deal with details. Not everything can be predicted, so
    a sportsmanlike spirit is mentioned. Finally, it should be
    clear which of several rule sets takes precedence.

    6.7 Tournament Organization

    A regional tournament can be organized by a club. Big events
    can be held at the request of an association or federation,
    who also supervise. A tournament organization is responsible
    for providing a venue and playing material. It must be
    distinguished from the tournament director and his assistant
    directors, who perform the particular tasks of pairing,
    collecting results, and ensuring smooth running. Shared
    power furthermore demands independent referees.

    6.8 Jurisdiction

    Before the start of a tournament valid instances of a
    jurisdiction as well as the persons to be referees must be
    clear. Typically, for a tournament itself there is one
    referee as the first instance and a body of three referees
    as the second instance. For very peculiar cases a federation
    could have a third and final instance. Some tournament rules
    replace the second instance by a single person, called chief
    referee; to avoid confusion he ought not to judge as the
    first instance. Players should respect the referees' tough
    job of mediation or decision; referees should seriously
    enforce the rules.

    6.9 Prizes

    The first places of a tournament invoke major prizes. E.g.
    the first, second, third places might get 3/6, 2/6, 1/6 of
    the available money. In a tournament with many weaker
    players it is a good idea to provide some prizes for all
    other players that win most rounds as well. While prizes can
    be money, books, trophies, etc., one should remember that
    money is most universally accepted and trophies serve the
    media better than the winners. -
    On a related topic, a side event lottery must give equal
    chances to all participants. This is only achieved by using
    one lot for each.

    7 Links

    Most rules information, links, short rules: http://home.snafu.de/jasiek/rules.html

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Bill@21:1/5 to Robert Jasiek on Mon Feb 12 21:50:54 2018
    Robert,

    Maybe consider updating, as necessary, the details at sensei's
    library--where someone might actually look for details about the rules
    of Go, instead of posting it over and over here, verbatim?
    By the way, are you actually the author of this piece of work, or did
    you just assume the role?

    Cheerfully,
    Bill

    Robert Jasiek wrote:
    Title: Rules FAQ
    Author: Robert Jasiek <jasiek@snafu.de>
    Frequency: monthly
    Last Update: 2017-10-13; First Day: 1999-04-12
    Distribution: rec.games.go
    Copyright: free non-commercial usage for promotion

    0 CONTENTS

    1 Purpose of this Paper
    2 Information for Beginners
    3 Important Concepts
    4 Particular Rules
    5 Troublesome Details
    6 Tournament Rules
    7 Links

    1 PURPOSE OF THIS PAPER

    This paper is a basic reference for important rules terms,
    rules, and tournament rules. Beginners should read
    especially Chapters 2 and 3, players Chapters 3 to 5,
    tournament players and organizers Chapter 6.

    2 INFORMATION FOR BEGINNERS
    2.1 What Must I Know as a Beginner?

    The game is played on a grid board. Typically it has 19x19
    intersections, but 9x9 are also fine. Two players compete.
    The first player uses black stones, the other white.

    The players alternate. A player may play or pass. Playing
    is putting one's own stone on an empty intersection and
    removing any surrounded opposing stones. To avoid
    cycles, a play may not recreate any prior configuration of
    all stones on the board.

    Two successive passes end the game. Then the player with
    more intersections wins. Intersections are his if only his
    stones occupy or surround them.

    2.2 Which Rules do I Need as a Beginner?

    You can play with short rules as in 2.1. Other rules may
    be different, but the game is the same, i. e. strategy,
    tactics, and the score do not change. Extremely rare
    exceptions confirm this rule.

    The winner can be determined by area or by territory.
    Either includes empty intersections surrounded only by own
    stones. While area adds intersections occupied by own
    stones, territory adds opposing prisoners instead.

    All rules, except short rules, have further phases after
    alternation and before scoring. Towards a game end it is
    often clear which stones will be removed. The additional
    phases allow the players to agree on which stones shall be
    removed. Thereby final removals do not require alternation.

    Whether you score by area or by territory or whether you
    remove by alternation or by agreement should mainly depend
    on which rules are used by people you play with.

    2.3 Which Rules Should I Teach?

    One possibility is to use a board with 9x9 intersections,
    short rules as in 2.1, and count each player's score by
    using a finger to scan the board for his intersections.

    3 IMPORTANT CONCEPTS

    While strategy and tactics virtually remain the same,
    concepts vary in different rules. However, the following
    gives a comprehensive overview on standard terms.

    3.1 Stone, String

    The physical device that colours one intersection in a
    play is a STONE. Two intersections of the board are
    ADJACENT if they have a line but no intersection between
    them. Two intersections with either black, white, or no
    stones on them are CONNECTED if they are adjacent or if
    there is a chain of adjacent intersections of their type
    between them. A REGION consists of an intersection and
    any intersections connected to it. A black or white
    region is called a STRING.

    3.2 Surrounded

    An intersection of one colour is SURROUNDED by another
    colour if each leaving path reaches the other colour first
    after the one colour. Hereby it can only be surrounded
    black by white, white by black, empty by black, or empty
    by white. A region can be surrounded. For strings there is
    an alternative notion of no liberty (or breath). A LIBERTY
    of a string is an empty intersection adjacent to it. Thus
    a string is surrounded if and only if it has no liberty.

    3.3 Removal, Suicide

    A removal empties the intersections of surrounded stones
    if there are any. Hereby removal of opposing stones is
    executed first, if necessary. Rules may either require or
    forbid removal of own stones. This is called suicide or no
    suicide. In practice, suicide might be used for so called ko
    fights or in capturing races.

    3.4 Capture, Prisoner

    Rules that score territory call a removal a capture
    because all removed stones are seriously kept as prisoners.

    3.5 Move, Play, Pass

    The players have alternate turns. On each turn a player makes
    a move that is either a play or a pass. A play places one's
    own stone on an empty intersection. It can then include
    removal of surrounded stones, if any. A pass merely continues
    alternation by giving the opponent the next turn.

    3.6 Compensation

    The first move advantage by black can be compensated by
    compensation points (komi) that are added to the white score
    after the game end. Komi can be adjusted by 0.5 to avoid
    ties. Today integer values for komi for 19x19 boards
    typically range between 5 and 7. For 13x13 boards one should
    use 8, for 9x9 boards 6; however, there is no real consensus
    for small board komi values yet. -
    A weaker player (black) can get the right to place an agreed
    number of compensation stones (handicap) before white's first
    play. Rules may allow free or fixed handicap. Free handicap
    does not apply any restriction. Fixed handicap requires
    traditional placement on set intersections.

    3.7 Phases

    Normally, a game consists of the phases alternation,
    agreement, scoring. A game stop is between alternation and
    agreement, the game end is between agreement and scoring,
    and after scoring both players accept the counted score as
    the result. The main part of the game is the alternation
    phase. Special rules are invoked after it. Typically, two
    successive passes in alternation are the game stop and start
    the agreement phase. In it the players may agree on strings
    to be removed. If they agree, then they remove those strings
    from the board; this ends the game. Sometimes they might
    disagree, then no strings are removed but alternation is
    resumed as if the last game stop did not occur.

    3.8 Recreation

    The position is the pattern of black and white stones on the
    board. Without extra rule a position might be repeated
    infinitely. The easiest rule to prohibit this says: A play
    may not recreate a position. This refers to positions after
    completion of plays, i.e. after possible removals. The rule
    is called "superko". -
    Some rules use concepts different from superko. They combine
    a "2-play rule" with a "long cycle rule". The first says:
    Two successive plays may not recreate a position. The second
    says: If a position is recreated after more than two moves,
    then the game ends either immediately or, as a variant, as
    soon as the players agree, with the result "without result".
    In practice the 2-play rule is sufficient for almost all
    cases. It handles the relevant standard pattern of two
    adjacent intersections. For superko this is just a special
    application.

    3.9 Scoring

    The score is the result after the game end as defined by
    the rules. There are two different scoring methods: area
    scoring and territory scoring. Rules use one of them. Both
    give the same result in almost all cases and both evaluate
    the difference of the black and the white scores. A player's
    AREA score is the sum of intersections with own stones and
    of empty intersections surrounded only by own stones. Simply
    speaking, a player's TERRITORY score is the sum of empty
    intersections surrounded only by own stones and of prisoners
    of opposing colour. With both scoring methods empty
    intersections that are not surrounded by either black or
    white are neutral.

    3.10 Counting

    A score must be determined by some mechanical procedure in
    practice; this is called counting. There are various methods.
    Some rules prescribe one. A possible method is to use one's
    finger to count point by point. Other methods rearrange a lot
    of stones on the board.

    4 PARTICULAR RULES

    Rules vary extremely. However, in practice they often give
    the same result.

    4.1 Short Rules

    Examples of short rules are the Simple Rules or the
    Tromp-Taylor rules. They have no game stop and no agreement.
    Both are superfluous since necessary removals may already be
    performed in the alternation. Two successive passes end the
    game that is scored then. Short rules use area scoring,
    superko, and suicide. Further settings are left for
    tournament rules.

    4.2 American Rules

    These are used by the American Go Association. They use
    situational superko, no suicide, and 7.5 komi. They permit
    free or fixed handicap. Their most remarkable feature is to
    allow one of area scoring or territory scoring. Herefore
    pass stones (one prisoner compensates each pass) and white
    moving last always ensure the same result, regardless of the
    applied scoring method.

    4.3 Chinese Rules

    These are used in continental China and sometimes in other
    countries. Area scoring and no suicide are used.

    4.3.1 Official Chinese Rules

    In practice, ko rules roughly amount to a 2-play rule and a
    long cycle rule. The mentioned superko is overridden. The
    counting is a sophisticated half counting, where empty
    intersections and then after rearrangements stones of one
    colour are added to be compared with half the non-neutral
    intersections. The komi as a half komi is 3.75. In full
    counting, counts and komi would be twice as big.

    4.3.2 Simplified Chinese Rules

    Positional superko is used. A counting method is not
    prescribed. The full komi should be 7.5.

    4.4 Japanese Rules

    The differences mainly affect handling of late game phases
    but often do not alter scores. Japanese rules use some
    traditional territory scoring that attempts to exclude so
    called sekis. No suicide applies. The core of the ko rules
    is a 2-play rule and a long cycle rule. Typically, komi is
    6.5. Fixed handicap should be used. The counting is a
    sophisticated rearrangement of empty intersections and
    filling-in of prisoners.

    4.4.1 Game Finishing Process

    A game finishes with the following process: 1) So called
    dame (neutral points) and defensive moves (necessary
    connections etc. due to occupied dame) are filled.
    2) The hypothetical analysis, which presumes perfect play,
    determines so called life or death of each string and the
    scoring intersections. 3) Without making any approach moves,
    dead stones are removed from scoring intersections and added
    to the prisoners. 4) The score is counted. (2) and (3) do not
    allow to play out life and death since actually filling
    intersections costs points in Japanese rules.

    4.4.2 Official Japanese Rules

    There are the Japanese 1989 Rules, which are used in Japan
    and elsewhere, and the World Amateur Go Championships Rules,
    which are used in some particular tournaments. Korean rules
    are similar to Japanese rules but have a very different text
    and differ in rare positions. Official Japanese rules are
    very incomplete and have messy late game phases. E.g., the
    Japanese 1989 Rules allow filling of dame during alternation,
    after it, or both and have a so called ko-pass-rule for the
    hypothetical analysis. Now professional Japanese rules are
    explained precisely by a rules expert's interpretation called
    "the Japanese 2003 Rules".

    4.4.3 Simplified Japanese Rules

    As a recent invention, they are not used yet. They are
    complete and have clear late game phases. Filling of dame is
    done during alternation.

    4.4.4 Verbal Japanese Rules

    They are used for informal games in many countries and
    undefined, except that the game finishing process is used.
    In a tournament without any official rules of play, disputes
    are not solved due to the rules but with a referee.

    4.5 Ing Rules

    Ing rules use area scoring, suicide, 8 komi with black
    winning ties, and free handicap.

    4.5.1 Official Ing Rules

    The ko rules are a mess but somehow resemble superko.
    Details could fill books. The late game phases are specified
    insufficiently. The peculiar counting method requires 180
    stones of each colour throughout the game, fills any stones
    on the board after the game end, and leaves exactly one
    empty intersection, which determines the winner. The
    official rules are used in professional Taiwanese and some
    sponsored tournaments. Taiwanese amateurs have their own
    rules.

    4.5.2 Simplified Ing Rules

    Positional superko is used. A counting method is not
    prescribed. The late game phases are specified clearly. The
    simplified rules are used in EGF tournaments that are said
    to use Ing rules.

    4.6 New Zealand Rules

    Area scoring, suicide, situational superko, 7 komi, and free
    handicap are used.

    4.7 Go Server Rules

    Every go server has its own and often complicated rules, if
    any, so they cannot be given in detail here. Concerning
    "IGS rules", territory scoring, no suicide, a 2-play rule,
    fixed handicap, three game stopping passes, and captures in
    an agreement phase are used. Details about agreements and
    long cycles are not specified and lead to adjourned games in
    case of doubt. Komi is suggested but may be altered. Counting
    is automatic. "Yahoo" has territory scoring, no suicide, a
    2-play rule, two game stopping passes; long cycles and
    disagreements are not handled properly. On "email servers"
    players must agree on any rules. -
    Typically territory scoring on a go server means that neither
    points in any sekis are excluded nor pass stones are used.
    Thus while the Japanese seki exception is abandoned,
    disagreements about removals may lead to games without result
    since playing out can cost points.

    4.8 International Rules

    The international mailing list go-rules has proposed
    international rules, however, none are adopted yet. The core
    rules of play shall be clear, complete, and correct.
    Currently alternative texts are offered for suicide,
    recreation, and scoring. Especially unification of scoring
    methods is advocated.

    4.9 EGF Rules

    The EGF uses the Simplified Ing Rules with 8 komi (black
    wins ties) in Ing sponsored tournaments and the Nihon Kiin
    1989 Rules with 6.5 komi in Japanese/Korean sponsored
    tournaments. If significantly the European Go Championship
    has both kinds of sponsors, then boards 1-16 use the Nihon
    Kiin 1989 Rules and boards 17+ the Simplified Ing Rules.
    However, time settings depend on ranks.

    5 TROUBLESOME DETAILS

    5.1 Colour Choice

    In even games typically the colours are randomly chosen. In
    handicap games black receives the handicap stones. -
    A manual method for randomly choosing colours is called
    nigiri. The older player hides a number of white stones
    taken from the bowl, the opponent takes one or two black
    stones to guess the parity, and the parity of the number of
    white stones is revealed. If the opponent guesses right,
    then he takes black, else he takes white.

    5.2 Pass Stones

    Some rules use pass stones. A passing player adds one own
    stone to the prisoners. As a consequence, captures before
    the game end can be resolved in alternation without any loss
    because any not answered approach move is compensated by one
    pass stone. With traditional territory scoring that uses no
    pass stones definition problems arise due to this missing
    option. Modern territory scoring or equivalence scoring use
    pass stones.

    5.3 Equivalence

    Area scoring and territory scoring are close because either
    intersections occupied by own stones or opposing prisoners
    are used. Essentially, every prisoner is a stone removed
    from some intersection. For area it scores one point less
    for the stone's player while for territory it scores one
    point more for his opponent. This is equal. Exact equality
    for the entire game must also consider passes by using pass
    stones and an equal number of moves by requiring white to
    pass last. This is done by equivalence scoring.

    5.4 Meaning of Agreement Removals

    Removals in an agreement phase under area scoring are fair
    because they may as well occur in alternation. Removing a
    stone due to agreement includes its then empty intersection
    and all adjacent empty intersections in the score. Removing
    a stone by means of alternation includes its then empty
    intersection and all adjacent newly occupied intersections
    in the score. -
    With traditional territory scoring this is not possible
    since stones on the board do not score. Thus final captures
    must occur after the game end due to attempted definitions
    in the rules.

    5.5 Practical Scoring Differences

    Since area scoring and modern territory scoring using pass
    stones are equal, correct play is the same for both. Apart
    from Japanese rules exceptions like not scoring empty
    intersections especially in asymmetrical coexistences or
    like a pass-for-ko-rule, traditional territory scoring can
    make a different winner in practically ca. every 10000th
    even game. This is so rare because of a parity feature
    combined with a scarcely odd number of intersections that
    are in coexistences but do not score for area at the game
    end. With area scoring a komi change from 1.5, 3.5, 5.5, ...
    to 2.5, 4.5, 6.5, ... almost always would not change the
    winner. So altough occupying the last empty intersections
    that would otherwise not score just before a game stop gains
    one point each, alternately doing so leaves a total
    advantage of at most one point. Due to the parity feature
    the player to get it is predetermined when this occupation
    starts. More importantly, one final ko is worth 1 point under
    traditional territory scoring but 2 or rarely 4 points under
    area scoring. Rare one-sided points in coexistences provide
    only area. Other practical differences are even rarer. Cute
    players include the stones in their endgame value counts
    during the middle of an area scoring game.

    5.6 Stone Scoring

    In ancient times stone scoring was popular. Only stones on
    the board are scored. Thus empty intersections surrounded by
    own stones are filled until necessary so called eyes remain.
    Disconnected stones require more eyes in total, the so
    called group tax.

    5.7 Old Ing Scoring

    Old Ing rules allowed fractional scores by assigning points
    to neutral empty regions due to the percentage of black and
    white stones surrounding every region.

    5.8 Primitive Rules

    They do not have passes. Alternation ends when a player
    loses due to no legal play. Games can be extremely long and
    include special strategies, so called pass fights. Primitive
    rules (also called no pass rules or Conway rules) can be
    useful in mathematics.

    5.9 Tradition

    Historically, exceptions arose, which some like as such
    especially together with Japanese style rules. So called
    sekis are excluded from the score. Special positions, termed
    precedents, have special rules. Modern Japanese rules have
    generalized a lot of them by a pass-for-ko-rule. After the
    game stop or after the game end and particularly in
    hypothetical play a stone captured in a possible 2-play cycle
    may not be recaptured unless before a pass is made that
    specifies the particular 2-play cycle.

    5.10 Positional / Situational Superko

    Positional superko prohibits a play that recreates a position.
    Situational superko refers to the situation, i.e. to the
    position together with the right to move. So a play is
    prohibited if it recreates a position while the same player
    has the right to move. In practice the differences are
    extremely rare.

    5.11 Handicap Recompensation

    With area scoring handicap stones beyond the first provide
    a potential extra area of one point per handicap stone. Komi
    for white may consider this. Recompensation, H-1 points for H
    handicap stones, is virtually only used together with
    American rules.

    5.12 Mathematics

    Go is a complete information game, i.e. at every move each
    player knows the entire game situation. Hence theoretically
    an algorithm could determine perfect play. However, due to
    the complexity of the game with N intersections, for which
    it is provably impossible to devise a polynomial time
    solution, perfect play or ideal komi are unknown. What one
    does know is that in a game without komi the first player wins
    or ties and that perfect play is independent of set komi. Many
    other propositions have been discovered, some of which
    describe the relation between area and territory scoring, solve
    tiny endgame positions or cyclical behaviour. -
    Go is a very complex game! According to John Tromp, the number
    of legal positions is:

    208168199381979984699478633344862770286522453884530548425 639456820927419612738015378525648451698519643907259916015 628128546089888314427129715319317557736620397247064840935

    For positional superko, no passes, and no resignation, the
    number of possible games is smaller than N**L(N) because L(N)
    also restricts the maximal number of moves per game and there
    are at most N possible intersections per move. (The sign ** is
    a text file notation for "to the power".) -
    Extremely modest estimates look like 10**N, which is based on
    an assumption of 10 reasonable intersections per move. A
    popular estimate for 19x19 go is 10**761, which must have
    originated from a typo and should be 10**361, if at all...
    These types of estimates are so popular because humans cannot
    even imagine the suggested number of atoms in the universe,
    10**80. For comparison, 3**361 is ca. 10**172.

    6 TOURNAMENT RULES

    6.1 Special Game Ends

    If the score considering the komi is zero, then the game is a
    tie and should be treated as 0.5 won games for each. Special
    rules or undue behaviour like sincere lateness might result
    in a referee declaring a win by forfeit, 0:0, or 1:1,
    whichever is most appropriate.

    6.2 Tournament Systems

    A tournament might consist of several stages, of which each
    has a seed and a system. A seed appropriately restricts
    participation, e.g. due to qualification. The most important
    systems are match, league, knockout, Swiss, McMahon. There
    are many others and hybrids. A system must fit the aims of a
    tournament. A sufficient number of rounds, a proper seed,
    and colour variation ensure a fair determination of the best
    player. -
    A match takes place between two players that either play a
    set number of games to see who wins more or a maximal number
    of games to see who wins a predetermined number of games
    first. In a league a small, usually even number of players
    performs a round-robin tournament, so that in each round all
    players play and every two players play against each other,
    one game e.g. A knockout preferably starts with a number of
    players that is a power of two. Losing players are eliminated,
    winning players continue until the winner remains. -
    In a Swiss system before each round each player's achieved
    number of wins is used to pair players with equal numbers as
    far as possible. So all players play all rounds and some time
    the best player will emerge. However, with greatly varying
    strengths too many rounds would be needed. So Swiss is only
    useful for particular events or handicap tournaments.
    McMahon is the refinement of Swiss. Before the start of the
    tournament all players are classified in rank groups, with
    ranks R from 0 to T. This means that one assumes a preceding
    Swiss tournament where every player has already won R games.
    Then in the McMahon tournament the strongest players, who
    deserve the rank T, compete for the top places. In practice,
    one uses a bar B, that is 1 or 2 ranks below T, so that all
    ranks above B are contracted to B and also players slightly
    weaker than the top players get their chance. All players in
    a McMahon play roughly equal opponents; if they win or lose,
    then the opponents will be stronger or weaker.

    6.3 Tie Breakers

    Tie breakers can refine pairings or results. Typically the
    first criterion is the number of wins (or McMahon points);
    all further criteria, if any, are tie breakers. They attempt
    a refinement where a low number of rounds and a tournament
    system do not guarantee sufficient distinction between
    players' achievements. However, they must be applied with
    care since they are only marginally better than coin tossing.
    Examples of tie breakers are direct comparison, which
    acknowledges the winner of a game between two players in
    question, and SOS, which is the Sum of Opponents' Scores. -
    The possible degree of quality of tie breakers is subject to
    discussion. It depends on tournament system, whether only the
    top or all players shall be distinguished, and other factors.
    An alternative to the usage of tie breakers for the final
    results ordering is issuing shared places for all players
    with the same number of wins (or McMahon points). - One must
    fairly assign tie breaker points for opponents missing in
    some round; enforcing participation is preferable especially
    for top players.

    6.4 Pairing

    Pairings must be fair, precise, and consider prior
    achievements during a tournament. One should consider colour
    balance and no pair twice, one might also aim at avoiding a
    pair of players from the same club or country, depending on
    a tournament's intentions. Pairings might be done manually
    in small tournaments; for most tournaments pairing programs
    should be used. These can create fair pairings convincingly,
    some even watch global balance.

    6.5 Thinking Times

    The age of killing each other by greater endurance has gone.
    Clocks are used to count each player's remaining thinking
    time. Typically, every game has a basic time and overtime
    periods. Exceeding a time limit loses a game. Basic time
    might be 9 hours for a professional top game, 10 minutes for
    a lightning game, or something in between that fits a
    tournament's intentions. An overtime period requires a fixed
    number of moves within a predetermined period, e.g. 1 move
    within 60 seconds. A move is finished by pressing the clock.
    - Many variants or other time systems exist, e.g., increasing
    numbers of moves in further overtime periods, penalty points
    for entering further periods, full usage of every overtime
    period, thinking time working like an hour glass, etc.

    6.6 Tournament Rules

    Every tournament uses an announced set of tournament rules.
    They especially specify the used set for the core rules of
    play, the tournament system, tie breakers, the pairing
    method, the winning criteria, compensation methods,
    thinking times, direction, jurisdiction, adjournment
    methods, penalities for being late, etc. Tournament rules
    often deal with details. Not everything can be predicted, so
    a sportsmanlike spirit is mentioned. Finally, it should be
    clear which of several rule sets takes precedence.

    6.7 Tournament Organization

    A regional tournament can be organized by a club. Big events
    can be held at the request of an association or federation,
    who also supervise. A tournament organization is responsible
    for providing a venue and playing material. It must be
    distinguished from the tournament director and his assistant
    directors, who perform the particular tasks of pairing,
    collecting results, and ensuring smooth running. Shared
    power furthermore demands independent referees.

    6.8 Jurisdiction

    Before the start of a tournament valid instances of a
    jurisdiction as well as the persons to be referees must be
    clear. Typically, for a tournament itself there is one
    referee as the first instance and a body of three referees
    as the second instance. For very peculiar cases a federation
    could have a third and final instance. Some tournament rules
    replace the second instance by a single person, called chief
    referee; to avoid confusion he ought not to judge as the
    first instance. Players should respect the referees' tough
    job of mediation or decision; referees should seriously
    enforce the rules.

    6.9 Prizes

    The first places of a tournament invoke major prizes. E.g.
    the first, second, third places might get 3/6, 2/6, 1/6 of
    the available money. In a tournament with many weaker
    players it is a good idea to provide some prizes for all
    other players that win most rounds as well. While prizes can
    be money, books, trophies, etc., one should remember that
    money is most universally accepted and trophies serve the
    media better than the winners. -
    On a related topic, a side event lottery must give equal
    chances to all participants. This is only achieved by using
    one lot for each.

    7 Links

    Most rules information, links, short rules: http://home.snafu.de/jasiek/rules.html

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Robert Jasiek@21:1/5 to All on Mon Mar 12 09:17:09 2018
    Title: Rules FAQ
    Author: Robert Jasiek <jasiek@snafu.de>
    Frequency: monthly
    Last Update: 2017-10-13; First Day: 1999-04-12
    Distribution: rec.games.go
    Copyright: free non-commercial usage for promotion

    0 CONTENTS

    1 Purpose of this Paper
    2 Information for Beginners
    3 Important Concepts
    4 Particular Rules
    5 Troublesome Details
    6 Tournament Rules
    7 Links

    1 PURPOSE OF THIS PAPER

    This paper is a basic reference for important rules terms,
    rules, and tournament rules. Beginners should read
    especially Chapters 2 and 3, players Chapters 3 to 5,
    tournament players and organizers Chapter 6.

    2 INFORMATION FOR BEGINNERS
    2.1 What Must I Know as a Beginner?

    The game is played on a grid board. Typically it has 19x19
    intersections, but 9x9 are also fine. Two players compete.
    The first player uses black stones, the other white.

    The players alternate. A player may play or pass. Playing
    is putting one's own stone on an empty intersection and
    removing any surrounded opposing stones. To avoid
    cycles, a play may not recreate any prior configuration of
    all stones on the board.

    Two successive passes end the game. Then the player with
    more intersections wins. Intersections are his if only his
    stones occupy or surround them.

    2.2 Which Rules do I Need as a Beginner?

    You can play with short rules as in 2.1. Other rules may
    be different, but the game is the same, i. e. strategy,
    tactics, and the score do not change. Extremely rare
    exceptions confirm this rule.

    The winner can be determined by area or by territory.
    Either includes empty intersections surrounded only by own
    stones. While area adds intersections occupied by own
    stones, territory adds opposing prisoners instead.

    All rules, except short rules, have further phases after
    alternation and before scoring. Towards a game end it is
    often clear which stones will be removed. The additional
    phases allow the players to agree on which stones shall be
    removed. Thereby final removals do not require alternation.

    Whether you score by area or by territory or whether you
    remove by alternation or by agreement should mainly depend
    on which rules are used by people you play with.

    2.3 Which Rules Should I Teach?

    One possibility is to use a board with 9x9 intersections,
    short rules as in 2.1, and count each player's score by
    using a finger to scan the board for his intersections.

    3 IMPORTANT CONCEPTS

    While strategy and tactics virtually remain the same,
    concepts vary in different rules. However, the following
    gives a comprehensive overview on standard terms.

    3.1 Stone, String

    The physical device that colours one intersection in a
    play is a STONE. Two intersections of the board are
    ADJACENT if they have a line but no intersection between
    them. Two intersections with either black, white, or no
    stones on them are CONNECTED if they are adjacent or if
    there is a chain of adjacent intersections of their type
    between them. A REGION consists of an intersection and
    any intersections connected to it. A black or white
    region is called a STRING.

    3.2 Surrounded

    An intersection of one colour is SURROUNDED by another
    colour if each leaving path reaches the other colour first
    after the one colour. Hereby it can only be surrounded
    black by white, white by black, empty by black, or empty
    by white. A region can be surrounded. For strings there is
    an alternative notion of no liberty (or breath). A LIBERTY
    of a string is an empty intersection adjacent to it. Thus
    a string is surrounded if and only if it has no liberty.

    3.3 Removal, Suicide

    A removal empties the intersections of surrounded stones
    if there are any. Hereby removal of opposing stones is
    executed first, if necessary. Rules may either require or
    forbid removal of own stones. This is called suicide or no
    suicide. In practice, suicide might be used for so called ko
    fights or in capturing races.

    3.4 Capture, Prisoner

    Rules that score territory call a removal a capture
    because all removed stones are seriously kept as prisoners.

    3.5 Move, Play, Pass

    The players have alternate turns. On each turn a player makes
    a move that is either a play or a pass. A play places one's
    own stone on an empty intersection. It can then include
    removal of surrounded stones, if any. A pass merely continues
    alternation by giving the opponent the next turn.

    3.6 Compensation

    The first move advantage by black can be compensated by
    compensation points (komi) that are added to the white score
    after the game end. Komi can be adjusted by 0.5 to avoid
    ties. Today integer values for komi for 19x19 boards
    typically range between 5 and 7. For 13x13 boards one should
    use 8, for 9x9 boards 6; however, there is no real consensus
    for small board komi values yet. -
    A weaker player (black) can get the right to place an agreed
    number of compensation stones (handicap) before white's first
    play. Rules may allow free or fixed handicap. Free handicap
    does not apply any restriction. Fixed handicap requires
    traditional placement on set intersections.

    3.7 Phases

    Normally, a game consists of the phases alternation,
    agreement, scoring. A game stop is between alternation and
    agreement, the game end is between agreement and scoring,
    and after scoring both players accept the counted score as
    the result. The main part of the game is the alternation
    phase. Special rules are invoked after it. Typically, two
    successive passes in alternation are the game stop and start
    the agreement phase. In it the players may agree on strings
    to be removed. If they agree, then they remove those strings
    from the board; this ends the game. Sometimes they might
    disagree, then no strings are removed but alternation is
    resumed as if the last game stop did not occur.

    3.8 Recreation

    The position is the pattern of black and white stones on the
    board. Without extra rule a position might be repeated
    infinitely. The easiest rule to prohibit this says: A play
    may not recreate a position. This refers to positions after
    completion of plays, i.e. after possible removals. The rule
    is called "superko". -
    Some rules use concepts different from superko. They combine
    a "2-play rule" with a "long cycle rule". The first says:
    Two successive plays may not recreate a position. The second
    says: If a position is recreated after more than two moves,
    then the game ends either immediately or, as a variant, as
    soon as the players agree, with the result "without result".
    In practice the 2-play rule is sufficient for almost all
    cases. It handles the relevant standard pattern of two
    adjacent intersections. For superko this is just a special
    application.

    3.9 Scoring

    The score is the result after the game end as defined by
    the rules. There are two different scoring methods: area
    scoring and territory scoring. Rules use one of them. Both
    give the same result in almost all cases and both evaluate
    the difference of the black and the white scores. A player's
    AREA score is the sum of intersections with own stones and
    of empty intersections surrounded only by own stones. Simply
    speaking, a player's TERRITORY score is the sum of empty
    intersections surrounded only by own stones and of prisoners
    of opposing colour. With both scoring methods empty
    intersections that are not surrounded by either black or
    white are neutral.

    3.10 Counting

    A score must be determined by some mechanical procedure in
    practice; this is called counting. There are various methods.
    Some rules prescribe one. A possible method is to use one's
    finger to count point by point. Other methods rearrange a lot
    of stones on the board.

    4 PARTICULAR RULES

    Rules vary extremely. However, in practice they often give
    the same result.

    4.1 Short Rules

    Examples of short rules are the Simple Rules or the
    Tromp-Taylor rules. They have no game stop and no agreement.
    Both are superfluous since necessary removals may already be
    performed in the alternation. Two successive passes end the
    game that is scored then. Short rules use area scoring,
    superko, and suicide. Further settings are left for
    tournament rules.

    4.2 American Rules

    These are used by the American Go Association. They use
    situational superko, no suicide, and 7.5 komi. They permit
    free or fixed handicap. Their most remarkable feature is to
    allow one of area scoring or territory scoring. Herefore
    pass stones (one prisoner compensates each pass) and white
    moving last always ensure the same result, regardless of the
    applied scoring method.

    4.3 Chinese Rules

    These are used in continental China and sometimes in other
    countries. Area scoring and no suicide are used.

    4.3.1 Official Chinese Rules

    In practice, ko rules roughly amount to a 2-play rule and a
    long cycle rule. The mentioned superko is overridden. The
    counting is a sophisticated half counting, where empty
    intersections and then after rearrangements stones of one
    colour are added to be compared with half the non-neutral
    intersections. The komi as a half komi is 3.75. In full
    counting, counts and komi would be twice as big.

    4.3.2 Simplified Chinese Rules

    Positional superko is used. A counting method is not
    prescribed. The full komi should be 7.5.

    4.4 Japanese Rules

    The differences mainly affect handling of late game phases
    but often do not alter scores. Japanese rules use some
    traditional territory scoring that attempts to exclude so
    called sekis. No suicide applies. The core of the ko rules
    is a 2-play rule and a long cycle rule. Typically, komi is
    6.5. Fixed handicap should be used. The counting is a
    sophisticated rearrangement of empty intersections and
    filling-in of prisoners.

    4.4.1 Game Finishing Process

    A game finishes with the following process: 1) So called
    dame (neutral points) and defensive moves (necessary
    connections etc. due to occupied dame) are filled.
    2) The hypothetical analysis, which presumes perfect play,
    determines so called life or death of each string and the
    scoring intersections. 3) Without making any approach moves,
    dead stones are removed from scoring intersections and added
    to the prisoners. 4) The score is counted. (2) and (3) do not
    allow to play out life and death since actually filling
    intersections costs points in Japanese rules.

    4.4.2 Official Japanese Rules

    There are the Japanese 1989 Rules, which are used in Japan
    and elsewhere, and the World Amateur Go Championships Rules,
    which are used in some particular tournaments. Korean rules
    are similar to Japanese rules but have a very different text
    and differ in rare positions. Official Japanese rules are
    very incomplete and have messy late game phases. E.g., the
    Japanese 1989 Rules allow filling of dame during alternation,
    after it, or both and have a so called ko-pass-rule for the
    hypothetical analysis. Now professional Japanese rules are
    explained precisely by a rules expert's interpretation called
    "the Japanese 2003 Rules".

    4.4.3 Simplified Japanese Rules

    As a recent invention, they are not used yet. They are
    complete and have clear late game phases. Filling of dame is
    done during alternation.

    4.4.4 Verbal Japanese Rules

    They are used for informal games in many countries and
    undefined, except that the game finishing process is used.
    In a tournament without any official rules of play, disputes
    are not solved due to the rules but with a referee.

    4.5 Ing Rules

    Ing rules use area scoring, suicide, 8 komi with black
    winning ties, and free handicap.

    4.5.1 Official Ing Rules

    The ko rules are a mess but somehow resemble superko.
    Details could fill books. The late game phases are specified
    insufficiently. The peculiar counting method requires 180
    stones of each colour throughout the game, fills any stones
    on the board after the game end, and leaves exactly one
    empty intersection, which determines the winner. The
    official rules are used in professional Taiwanese and some
    sponsored tournaments. Taiwanese amateurs have their own
    rules.

    4.5.2 Simplified Ing Rules

    Positional superko is used. A counting method is not
    prescribed. The late game phases are specified clearly. The
    simplified rules are used in EGF tournaments that are said
    to use Ing rules.

    4.6 New Zealand Rules

    Area scoring, suicide, situational superko, 7 komi, and free
    handicap are used.

    4.7 Go Server Rules

    Every go server has its own and often complicated rules, if
    any, so they cannot be given in detail here. Concerning
    "IGS rules", territory scoring, no suicide, a 2-play rule,
    fixed handicap, three game stopping passes, and captures in
    an agreement phase are used. Details about agreements and
    long cycles are not specified and lead to adjourned games in
    case of doubt. Komi is suggested but may be altered. Counting
    is automatic. "Yahoo" has territory scoring, no suicide, a
    2-play rule, two game stopping passes; long cycles and
    disagreements are not handled properly. On "email servers"
    players must agree on any rules. -
    Typically territory scoring on a go server means that neither
    points in any sekis are excluded nor pass stones are used.
    Thus while the Japanese seki exception is abandoned,
    disagreements about removals may lead to games without result
    since playing out can cost points.

    4.8 International Rules

    The international mailing list go-rules has proposed
    international rules, however, none are adopted yet. The core
    rules of play shall be clear, complete, and correct.
    Currently alternative texts are offered for suicide,
    recreation, and scoring. Especially unification of scoring
    methods is advocated.

    4.9 EGF Rules

    The EGF uses the Simplified Ing Rules with 8 komi (black
    wins ties) in Ing sponsored tournaments and the Nihon Kiin
    1989 Rules with 6.5 komi in Japanese/Korean sponsored
    tournaments. If significantly the European Go Championship
    has both kinds of sponsors, then boards 1-16 use the Nihon
    Kiin 1989 Rules and boards 17+ the Simplified Ing Rules.
    However, time settings depend on ranks.

    5 TROUBLESOME DETAILS

    5.1 Colour Choice

    In even games typically the colours are randomly chosen. In
    handicap games black receives the handicap stones. -
    A manual method for randomly choosing colours is called
    nigiri. The older player hides a number of white stones
    taken from the bowl, the opponent takes one or two black
    stones to guess the parity, and the parity of the number of
    white stones is revealed. If the opponent guesses right,
    then he takes black, else he takes white.

    5.2 Pass Stones

    Some rules use pass stones. A passing player adds one own
    stone to the prisoners. As a consequence, captures before
    the game end can be resolved in alternation without any loss
    because any not answered approach move is compensated by one
    pass stone. With traditional territory scoring that uses no
    pass stones definition problems arise due to this missing
    option. Modern territory scoring or equivalence scoring use
    pass stones.

    5.3 Equivalence

    Area scoring and territory scoring are close because either
    intersections occupied by own stones or opposing prisoners
    are used. Essentially, every prisoner is a stone removed
    from some intersection. For area it scores one point less
    for the stone's player while for territory it scores one
    point more for his opponent. This is equal. Exact equality
    for the entire game must also consider passes by using pass
    stones and an equal number of moves by requiring white to
    pass last. This is done by equivalence scoring.

    5.4 Meaning of Agreement Removals

    Removals in an agreement phase under area scoring are fair
    because they may as well occur in alternation. Removing a
    stone due to agreement includes its then empty intersection
    and all adjacent empty intersections in the score. Removing
    a stone by means of alternation includes its then empty
    intersection and all adjacent newly occupied intersections
    in the score. -
    With traditional territory scoring this is not possible
    since stones on the board do not score. Thus final captures
    must occur after the game end due to attempted definitions
    in the rules.

    5.5 Practical Scoring Differences

    Since area scoring and modern territory scoring using pass
    stones are equal, correct play is the same for both. Apart
    from Japanese rules exceptions like not scoring empty
    intersections especially in asymmetrical coexistences or
    like a pass-for-ko-rule, traditional territory scoring can
    make a different winner in practically ca. every 10000th
    even game. This is so rare because of a parity feature
    combined with a scarcely odd number of intersections that
    are in coexistences but do not score for area at the game
    end. With area scoring a komi change from 1.5, 3.5, 5.5, ...
    to 2.5, 4.5, 6.5, ... almost always would not change the
    winner. So altough occupying the last empty intersections
    that would otherwise not score just before a game stop gains
    one point each, alternately doing so leaves a total
    advantage of at most one point. Due to the parity feature
    the player to get it is predetermined when this occupation
    starts. More importantly, one final ko is worth 1 point under
    traditional territory scoring but 2 or rarely 4 points under
    area scoring. Rare one-sided points in coexistences provide
    only area. Other practical differences are even rarer. Cute
    players include the stones in their endgame value counts
    during the middle of an area scoring game.

    5.6 Stone Scoring

    In ancient times stone scoring was popular. Only stones on
    the board are scored. Thus empty intersections surrounded by
    own stones are filled until necessary so called eyes remain.
    Disconnected stones require more eyes in total, the so
    called group tax.

    5.7 Old Ing Scoring

    Old Ing rules allowed fractional scores by assigning points
    to neutral empty regions due to the percentage of black and
    white stones surrounding every region.

    5.8 Primitive Rules

    They do not have passes. Alternation ends when a player
    loses due to no legal play. Games can be extremely long and
    include special strategies, so called pass fights. Primitive
    rules (also called no pass rules or Conway rules) can be
    useful in mathematics.

    5.9 Tradition

    Historically, exceptions arose, which some like as such
    especially together with Japanese style rules. So called
    sekis are excluded from the score. Special positions, termed
    precedents, have special rules. Modern Japanese rules have
    generalized a lot of them by a pass-for-ko-rule. After the
    game stop or after the game end and particularly in
    hypothetical play a stone captured in a possible 2-play cycle
    may not be recaptured unless before a pass is made that
    specifies the particular 2-play cycle.

    5.10 Positional / Situational Superko

    Positional superko prohibits a play that recreates a position.
    Situational superko refers to the situation, i.e. to the
    position together with the right to move. So a play is
    prohibited if it recreates a position while the same player
    has the right to move. In practice the differences are
    extremely rare.

    5.11 Handicap Recompensation

    With area scoring handicap stones beyond the first provide
    a potential extra area of one point per handicap stone. Komi
    for white may consider this. Recompensation, H-1 points for H
    handicap stones, is virtually only used together with
    American rules.

    5.12 Mathematics

    Go is a complete information game, i.e. at every move each
    player knows the entire game situation. Hence theoretically
    an algorithm could determine perfect play. However, due to
    the complexity of the game with N intersections, for which
    it is provably impossible to devise a polynomial time
    solution, perfect play or ideal komi are unknown. What one
    does know is that in a game without komi the first player wins
    or ties and that perfect play is independent of set komi. Many
    other propositions have been discovered, some of which
    describe the relation between area and territory scoring, solve
    tiny endgame positions or cyclical behaviour. -
    Go is a very complex game! According to John Tromp, the number
    of legal positions is:

    208168199381979984699478633344862770286522453884530548425 639456820927419612738015378525648451698519643907259916015 628128546089888314427129715319317557736620397247064840935

    For positional superko, no passes, and no resignation, the
    number of possible games is smaller than N**L(N) because L(N)
    also restricts the maximal number of moves per game and there
    are at most N possible intersections per move. (The sign ** is
    a text file notation for "to the power".) -
    Extremely modest estimates look like 10**N, which is based on
    an assumption of 10 reasonable intersections per move. A
    popular estimate for 19x19 go is 10**761, which must have
    originated from a typo and should be 10**361, if at all...
    These types of estimates are so popular because humans cannot
    even imagine the suggested number of atoms in the universe,
    10**80. For comparison, 3**361 is ca. 10**172.

    6 TOURNAMENT RULES

    6.1 Special Game Ends

    If the score considering the komi is zero, then the game is a
    tie and should be treated as 0.5 won games for each. Special
    rules or undue behaviour like sincere lateness might result
    in a referee declaring a win by forfeit, 0:0, or 1:1,
    whichever is most appropriate.

    6.2 Tournament Systems

    A tournament might consist of several stages, of which each
    has a seed and a system. A seed appropriately restricts
    participation, e.g. due to qualification. The most important
    systems are match, league, knockout, Swiss, McMahon. There
    are many others and hybrids. A system must fit the aims of a
    tournament. A sufficient number of rounds, a proper seed,
    and colour variation ensure a fair determination of the best
    player. -
    A match takes place between two players that either play a
    set number of games to see who wins more or a maximal number
    of games to see who wins a predetermined number of games
    first. In a league a small, usually even number of players
    performs a round-robin tournament, so that in each round all
    players play and every two players play against each other,
    one game e.g. A knockout preferably starts with a number of
    players that is a power of two. Losing players are eliminated,
    winning players continue until the winner remains. -
    In a Swiss system before each round each player's achieved
    number of wins is used to pair players with equal numbers as
    far as possible. So all players play all rounds and some time
    the best player will emerge. However, with greatly varying
    strengths too many rounds would be needed. So Swiss is only
    useful for particular events or handicap tournaments.
    McMahon is the refinement of Swiss. Before the start of the
    tournament all players are classified in rank groups, with
    ranks R from 0 to T. This means that one assumes a preceding
    Swiss tournament where every player has already won R games.
    Then in the McMahon tournament the strongest players, who
    deserve the rank T, compete for the top places. In practice,
    one uses a bar B, that is 1 or 2 ranks below T, so that all
    ranks above B are contracted to B and also players slightly
    weaker than the top players get their chance. All players in
    a McMahon play roughly equal opponents; if they win or lose,
    then the opponents will be stronger or weaker.

    6.3 Tie Breakers

    Tie breakers can refine pairings or results. Typically the
    first criterion is the number of wins (or McMahon points);
    all further criteria, if any, are tie breakers. They attempt
    a refinement where a low number of rounds and a tournament
    system do not guarantee sufficient distinction between
    players' achievements. However, they must be applied with
    care since they are only marginally better than coin tossing.
    Examples of tie breakers are direct comparison, which
    acknowledges the winner of a game between two players in
    question, and SOS, which is the Sum of Opponents' Scores. -
    The possible degree of quality of tie breakers is subject to
    discussion. It depends on tournament system, whether only the
    top or all players shall be distinguished, and other factors.
    An alternative to the usage of tie breakers for the final
    results ordering is issuing shared places for all players
    with the same number of wins (or McMahon points). - One must
    fairly assign tie breaker points for opponents missing in
    some round; enforcing participation is preferable especially
    for top players.

    6.4 Pairing

    Pairings must be fair, precise, and consider prior
    achievements during a tournament. One should consider colour
    balance and no pair twice, one might also aim at avoiding a
    pair of players from the same club or country, depending on
    a tournament's intentions. Pairings might be done manually
    in small tournaments; for most tournaments pairing programs
    should be used. These can create fair pairings convincingly,
    some even watch global balance.

    6.5 Thinking Times

    The age of killing each other by greater endurance has gone.
    Clocks are used to count each player's remaining thinking
    time. Typically, every game has a basic time and overtime
    periods. Exceeding a time limit loses a game. Basic time
    might be 9 hours for a professional top game, 10 minutes for
    a lightning game, or something in between that fits a
    tournament's intentions. An overtime period requires a fixed
    number of moves within a predetermined period, e.g. 1 move
    within 60 seconds. A move is finished by pressing the clock.
    - Many variants or other time systems exist, e.g., increasing
    numbers of moves in further overtime periods, penalty points
    for entering further periods, full usage of every overtime
    period, thinking time working like an hour glass, etc.

    6.6 Tournament Rules

    Every tournament uses an announced set of tournament rules.
    They especially specify the used set for the core rules of
    play, the tournament system, tie breakers, the pairing
    method, the winning criteria, compensation methods,
    thinking times, direction, jurisdiction, adjournment
    methods, penalities for being late, etc. Tournament rules
    often deal with details. Not everything can be predicted, so
    a sportsmanlike spirit is mentioned. Finally, it should be
    clear which of several rule sets takes precedence.

    6.7 Tournament Organization

    A regional tournament can be organized by a club. Big events
    can be held at the request of an association or federation,
    who also supervise. A tournament organization is responsible
    for providing a venue and playing material. It must be
    distinguished from the tournament director and his assistant
    directors, who perform the particular tasks of pairing,
    collecting results, and ensuring smooth running. Shared
    power furthermore demands independent referees.

    6.8 Jurisdiction

    Before the start of a tournament valid instances of a
    jurisdiction as well as the persons to be referees must be
    clear. Typically, for a tournament itself there is one
    referee as the first instance and a body of three referees
    as the second instance. For very peculiar cases a federation
    could have a third and final instance. Some tournament rules
    replace the second instance by a single person, called chief
    referee; to avoid confusion he ought not to judge as the
    first instance. Players should respect the referees' tough
    job of mediation or decision; referees should seriously
    enforce the rules.

    6.9 Prizes

    The first places of a tournament invoke major prizes. E.g.
    the first, second, third places might get 3/6, 2/6, 1/6 of
    the available money. In a tournament with many weaker
    players it is a good idea to provide some prizes for all
    other players that win most rounds as well. While prizes can
    be money, books, trophies, etc., one should remember that
    money is most universally accepted and trophies serve the
    media better than the winners. -
    On a related topic, a side event lottery must give equal
    chances to all participants. This is only achieved by using
    one lot for each.

    7 Links

    Most rules information, links, short rules: http://home.snafu.de/jasiek/rules.html

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Robert Jasiek@21:1/5 to All on Sat May 12 06:30:30 2018
    Title: Rules FAQ
    Author: Robert Jasiek <jasiek@snafu.de>
    Frequency: monthly
    Last Update: 2017-10-13; First Day: 1999-04-12
    Distribution: rec.games.go
    Copyright: free non-commercial usage for promotion

    0 CONTENTS

    1 Purpose of this Paper
    2 Information for Beginners
    3 Important Concepts
    4 Particular Rules
    5 Troublesome Details
    6 Tournament Rules
    7 Links

    1 PURPOSE OF THIS PAPER

    This paper is a basic reference for important rules terms,
    rules, and tournament rules. Beginners should read
    especially Chapters 2 and 3, players Chapters 3 to 5,
    tournament players and organizers Chapter 6.

    2 INFORMATION FOR BEGINNERS
    2.1 What Must I Know as a Beginner?

    The game is played on a grid board. Typically it has 19x19
    intersections, but 9x9 are also fine. Two players compete.
    The first player uses black stones, the other white.

    The players alternate. A player may play or pass. Playing
    is putting one's own stone on an empty intersection and
    removing any surrounded opposing stones. To avoid
    cycles, a play may not recreate any prior configuration of
    all stones on the board.

    Two successive passes end the game. Then the player with
    more intersections wins. Intersections are his if only his
    stones occupy or surround them.

    2.2 Which Rules do I Need as a Beginner?

    You can play with short rules as in 2.1. Other rules may
    be different, but the game is the same, i. e. strategy,
    tactics, and the score do not change. Extremely rare
    exceptions confirm this rule.

    The winner can be determined by area or by territory.
    Either includes empty intersections surrounded only by own
    stones. While area adds intersections occupied by own
    stones, territory adds opposing prisoners instead.

    All rules, except short rules, have further phases after
    alternation and before scoring. Towards a game end it is
    often clear which stones will be removed. The additional
    phases allow the players to agree on which stones shall be
    removed. Thereby final removals do not require alternation.

    Whether you score by area or by territory or whether you
    remove by alternation or by agreement should mainly depend
    on which rules are used by people you play with.

    2.3 Which Rules Should I Teach?

    One possibility is to use a board with 9x9 intersections,
    short rules as in 2.1, and count each player's score by
    using a finger to scan the board for his intersections.

    3 IMPORTANT CONCEPTS

    While strategy and tactics virtually remain the same,
    concepts vary in different rules. However, the following
    gives a comprehensive overview on standard terms.

    3.1 Stone, String

    The physical device that colours one intersection in a
    play is a STONE. Two intersections of the board are
    ADJACENT if they have a line but no intersection between
    them. Two intersections with either black, white, or no
    stones on them are CONNECTED if they are adjacent or if
    there is a chain of adjacent intersections of their type
    between them. A REGION consists of an intersection and
    any intersections connected to it. A black or white
    region is called a STRING.

    3.2 Surrounded

    An intersection of one colour is SURROUNDED by another
    colour if each leaving path reaches the other colour first
    after the one colour. Hereby it can only be surrounded
    black by white, white by black, empty by black, or empty
    by white. A region can be surrounded. For strings there is
    an alternative notion of no liberty (or breath). A LIBERTY
    of a string is an empty intersection adjacent to it. Thus
    a string is surrounded if and only if it has no liberty.

    3.3 Removal, Suicide

    A removal empties the intersections of surrounded stones
    if there are any. Hereby removal of opposing stones is
    executed first, if necessary. Rules may either require or
    forbid removal of own stones. This is called suicide or no
    suicide. In practice, suicide might be used for so called ko
    fights or in capturing races.

    3.4 Capture, Prisoner

    Rules that score territory call a removal a capture
    because all removed stones are seriously kept as prisoners.

    3.5 Move, Play, Pass

    The players have alternate turns. On each turn a player makes
    a move that is either a play or a pass. A play places one's
    own stone on an empty intersection. It can then include
    removal of surrounded stones, if any. A pass merely continues
    alternation by giving the opponent the next turn.

    3.6 Compensation

    The first move advantage by black can be compensated by
    compensation points (komi) that are added to the white score
    after the game end. Komi can be adjusted by 0.5 to avoid
    ties. Today integer values for komi for 19x19 boards
    typically range between 5 and 7. For 13x13 boards one should
    use 8, for 9x9 boards 6; however, there is no real consensus
    for small board komi values yet. -
    A weaker player (black) can get the right to place an agreed
    number of compensation stones (handicap) before white's first
    play. Rules may allow free or fixed handicap. Free handicap
    does not apply any restriction. Fixed handicap requires
    traditional placement on set intersections.

    3.7 Phases

    Normally, a game consists of the phases alternation,
    agreement, scoring. A game stop is between alternation and
    agreement, the game end is between agreement and scoring,
    and after scoring both players accept the counted score as
    the result. The main part of the game is the alternation
    phase. Special rules are invoked after it. Typically, two
    successive passes in alternation are the game stop and start
    the agreement phase. In it the players may agree on strings
    to be removed. If they agree, then they remove those strings
    from the board; this ends the game. Sometimes they might
    disagree, then no strings are removed but alternation is
    resumed as if the last game stop did not occur.

    3.8 Recreation

    The position is the pattern of black and white stones on the
    board. Without extra rule a position might be repeated
    infinitely. The easiest rule to prohibit this says: A play
    may not recreate a position. This refers to positions after
    completion of plays, i.e. after possible removals. The rule
    is called "superko". -
    Some rules use concepts different from superko. They combine
    a "2-play rule" with a "long cycle rule". The first says:
    Two successive plays may not recreate a position. The second
    says: If a position is recreated after more than two moves,
    then the game ends either immediately or, as a variant, as
    soon as the players agree, with the result "without result".
    In practice the 2-play rule is sufficient for almost all
    cases. It handles the relevant standard pattern of two
    adjacent intersections. For superko this is just a special
    application.

    3.9 Scoring

    The score is the result after the game end as defined by
    the rules. There are two different scoring methods: area
    scoring and territory scoring. Rules use one of them. Both
    give the same result in almost all cases and both evaluate
    the difference of the black and the white scores. A player's
    AREA score is the sum of intersections with own stones and
    of empty intersections surrounded only by own stones. Simply
    speaking, a player's TERRITORY score is the sum of empty
    intersections surrounded only by own stones and of prisoners
    of opposing colour. With both scoring methods empty
    intersections that are not surrounded by either black or
    white are neutral.

    3.10 Counting

    A score must be determined by some mechanical procedure in
    practice; this is called counting. There are various methods.
    Some rules prescribe one. A possible method is to use one's
    finger to count point by point. Other methods rearrange a lot
    of stones on the board.

    4 PARTICULAR RULES

    Rules vary extremely. However, in practice they often give
    the same result.

    4.1 Short Rules

    Examples of short rules are the Simple Rules or the
    Tromp-Taylor rules. They have no game stop and no agreement.
    Both are superfluous since necessary removals may already be
    performed in the alternation. Two successive passes end the
    game that is scored then. Short rules use area scoring,
    superko, and suicide. Further settings are left for
    tournament rules.

    4.2 American Rules

    These are used by the American Go Association. They use
    situational superko, no suicide, and 7.5 komi. They permit
    free or fixed handicap. Their most remarkable feature is to
    allow one of area scoring or territory scoring. Herefore
    pass stones (one prisoner compensates each pass) and white
    moving last always ensure the same result, regardless of the
    applied scoring method.

    4.3 Chinese Rules

    These are used in continental China and sometimes in other
    countries. Area scoring and no suicide are used.

    4.3.1 Official Chinese Rules

    In practice, ko rules roughly amount to a 2-play rule and a
    long cycle rule. The mentioned superko is overridden. The
    counting is a sophisticated half counting, where empty
    intersections and then after rearrangements stones of one
    colour are added to be compared with half the non-neutral
    intersections. The komi as a half komi is 3.75. In full
    counting, counts and komi would be twice as big.

    4.3.2 Simplified Chinese Rules

    Positional superko is used. A counting method is not
    prescribed. The full komi should be 7.5.

    4.4 Japanese Rules

    The differences mainly affect handling of late game phases
    but often do not alter scores. Japanese rules use some
    traditional territory scoring that attempts to exclude so
    called sekis. No suicide applies. The core of the ko rules
    is a 2-play rule and a long cycle rule. Typically, komi is
    6.5. Fixed handicap should be used. The counting is a
    sophisticated rearrangement of empty intersections and
    filling-in of prisoners.

    4.4.1 Game Finishing Process

    A game finishes with the following process: 1) So called
    dame (neutral points) and defensive moves (necessary
    connections etc. due to occupied dame) are filled.
    2) The hypothetical analysis, which presumes perfect play,
    determines so called life or death of each string and the
    scoring intersections. 3) Without making any approach moves,
    dead stones are removed from scoring intersections and added
    to the prisoners. 4) The score is counted. (2) and (3) do not
    allow to play out life and death since actually filling
    intersections costs points in Japanese rules.

    4.4.2 Official Japanese Rules

    There are the Japanese 1989 Rules, which are used in Japan
    and elsewhere, and the World Amateur Go Championships Rules,
    which are used in some particular tournaments. Korean rules
    are similar to Japanese rules but have a very different text
    and differ in rare positions. Official Japanese rules are
    very incomplete and have messy late game phases. E.g., the
    Japanese 1989 Rules allow filling of dame during alternation,
    after it, or both and have a so called ko-pass-rule for the
    hypothetical analysis. Now professional Japanese rules are
    explained precisely by a rules expert's interpretation called
    "the Japanese 2003 Rules".

    4.4.3 Simplified Japanese Rules

    As a recent invention, they are not used yet. They are
    complete and have clear late game phases. Filling of dame is
    done during alternation.

    4.4.4 Verbal Japanese Rules

    They are used for informal games in many countries and
    undefined, except that the game finishing process is used.
    In a tournament without any official rules of play, disputes
    are not solved due to the rules but with a referee.

    4.5 Ing Rules

    Ing rules use area scoring, suicide, 8 komi with black
    winning ties, and free handicap.

    4.5.1 Official Ing Rules

    The ko rules are a mess but somehow resemble superko.
    Details could fill books. The late game phases are specified
    insufficiently. The peculiar counting method requires 180
    stones of each colour throughout the game, fills any stones
    on the board after the game end, and leaves exactly one
    empty intersection, which determines the winner. The
    official rules are used in professional Taiwanese and some
    sponsored tournaments. Taiwanese amateurs have their own
    rules.

    4.5.2 Simplified Ing Rules

    Positional superko is used. A counting method is not
    prescribed. The late game phases are specified clearly. The
    simplified rules are used in EGF tournaments that are said
    to use Ing rules.

    4.6 New Zealand Rules

    Area scoring, suicide, situational superko, 7 komi, and free
    handicap are used.

    4.7 Go Server Rules

    Every go server has its own and often complicated rules, if
    any, so they cannot be given in detail here. Concerning
    "IGS rules", territory scoring, no suicide, a 2-play rule,
    fixed handicap, three game stopping passes, and captures in
    an agreement phase are used. Details about agreements and
    long cycles are not specified and lead to adjourned games in
    case of doubt. Komi is suggested but may be altered. Counting
    is automatic. "Yahoo" has territory scoring, no suicide, a
    2-play rule, two game stopping passes; long cycles and
    disagreements are not handled properly. On "email servers"
    players must agree on any rules. -
    Typically territory scoring on a go server means that neither
    points in any sekis are excluded nor pass stones are used.
    Thus while the Japanese seki exception is abandoned,
    disagreements about removals may lead to games without result
    since playing out can cost points.

    4.8 International Rules

    The international mailing list go-rules has proposed
    international rules, however, none are adopted yet. The core
    rules of play shall be clear, complete, and correct.
    Currently alternative texts are offered for suicide,
    recreation, and scoring. Especially unification of scoring
    methods is advocated.

    4.9 EGF Rules

    The EGF uses the Simplified Ing Rules with 8 komi (black
    wins ties) in Ing sponsored tournaments and the Nihon Kiin
    1989 Rules with 6.5 komi in Japanese/Korean sponsored
    tournaments. If significantly the European Go Championship
    has both kinds of sponsors, then boards 1-16 use the Nihon
    Kiin 1989 Rules and boards 17+ the Simplified Ing Rules.
    However, time settings depend on ranks.

    5 TROUBLESOME DETAILS

    5.1 Colour Choice

    In even games typically the colours are randomly chosen. In
    handicap games black receives the handicap stones. -
    A manual method for randomly choosing colours is called
    nigiri. The older player hides a number of white stones
    taken from the bowl, the opponent takes one or two black
    stones to guess the parity, and the parity of the number of
    white stones is revealed. If the opponent guesses right,
    then he takes black, else he takes white.

    5.2 Pass Stones

    Some rules use pass stones. A passing player adds one own
    stone to the prisoners. As a consequence, captures before
    the game end can be resolved in alternation without any loss
    because any not answered approach move is compensated by one
    pass stone. With traditional territory scoring that uses no
    pass stones definition problems arise due to this missing
    option. Modern territory scoring or equivalence scoring use
    pass stones.

    5.3 Equivalence

    Area scoring and territory scoring are close because either
    intersections occupied by own stones or opposing prisoners
    are used. Essentially, every prisoner is a stone removed
    from some intersection. For area it scores one point less
    for the stone's player while for territory it scores one
    point more for his opponent. This is equal. Exact equality
    for the entire game must also consider passes by using pass
    stones and an equal number of moves by requiring white to
    pass last. This is done by equivalence scoring.

    5.4 Meaning of Agreement Removals

    Removals in an agreement phase under area scoring are fair
    because they may as well occur in alternation. Removing a
    stone due to agreement includes its then empty intersection
    and all adjacent empty intersections in the score. Removing
    a stone by means of alternation includes its then empty
    intersection and all adjacent newly occupied intersections
    in the score. -
    With traditional territory scoring this is not possible
    since stones on the board do not score. Thus final captures
    must occur after the game end due to attempted definitions
    in the rules.

    5.5 Practical Scoring Differences

    Since area scoring and modern territory scoring using pass
    stones are equal, correct play is the same for both. Apart
    from Japanese rules exceptions like not scoring empty
    intersections especially in asymmetrical coexistences or
    like a pass-for-ko-rule, traditional territory scoring can
    make a different winner in practically ca. every 10000th
    even game. This is so rare because of a parity feature
    combined with a scarcely odd number of intersections that
    are in coexistences but do not score for area at the game
    end. With area scoring a komi change from 1.5, 3.5, 5.5, ...
    to 2.5, 4.5, 6.5, ... almost always would not change the
    winner. So altough occupying the last empty intersections
    that would otherwise not score just before a game stop gains
    one point each, alternately doing so leaves a total
    advantage of at most one point. Due to the parity feature
    the player to get it is predetermined when this occupation
    starts. More importantly, one final ko is worth 1 point under
    traditional territory scoring but 2 or rarely 4 points under
    area scoring. Rare one-sided points in coexistences provide
    only area. Other practical differences are even rarer. Cute
    players include the stones in their endgame value counts
    during the middle of an area scoring game.

    5.6 Stone Scoring

    In ancient times stone scoring was popular. Only stones on
    the board are scored. Thus empty intersections surrounded by
    own stones are filled until necessary so called eyes remain.
    Disconnected stones require more eyes in total, the so
    called group tax.

    5.7 Old Ing Scoring

    Old Ing rules allowed fractional scores by assigning points
    to neutral empty regions due to the percentage of black and
    white stones surrounding every region.

    5.8 Primitive Rules

    They do not have passes. Alternation ends when a player
    loses due to no legal play. Games can be extremely long and
    include special strategies, so called pass fights. Primitive
    rules (also called no pass rules or Conway rules) can be
    useful in mathematics.

    5.9 Tradition

    Historically, exceptions arose, which some like as such
    especially together with Japanese style rules. So called
    sekis are excluded from the score. Special positions, termed
    precedents, have special rules. Modern Japanese rules have
    generalized a lot of them by a pass-for-ko-rule. After the
    game stop or after the game end and particularly in
    hypothetical play a stone captured in a possible 2-play cycle
    may not be recaptured unless before a pass is made that
    specifies the particular 2-play cycle.

    5.10 Positional / Situational Superko

    Positional superko prohibits a play that recreates a position.
    Situational superko refers to the situation, i.e. to the
    position together with the right to move. So a play is
    prohibited if it recreates a position while the same player
    has the right to move. In practice the differences are
    extremely rare.

    5.11 Handicap Recompensation

    With area scoring handicap stones beyond the first provide
    a potential extra area of one point per handicap stone. Komi
    for white may consider this. Recompensation, H-1 points for H
    handicap stones, is virtually only used together with
    American rules.

    5.12 Mathematics

    Go is a complete information game, i.e. at every move each
    player knows the entire game situation. Hence theoretically
    an algorithm could determine perfect play. However, due to
    the complexity of the game with N intersections, for which
    it is provably impossible to devise a polynomial time
    solution, perfect play or ideal komi are unknown. What one
    does know is that in a game without komi the first player wins
    or ties and that perfect play is independent of set komi. Many
    other propositions have been discovered, some of which
    describe the relation between area and territory scoring, solve
    tiny endgame positions or cyclical behaviour. -
    Go is a very complex game! According to John Tromp, the number
    of legal positions is:

    208168199381979984699478633344862770286522453884530548425 639456820927419612738015378525648451698519643907259916015 628128546089888314427129715319317557736620397247064840935

    For positional superko, no passes, and no resignation, the
    number of possible games is smaller than N**L(N) because L(N)
    also restricts the maximal number of moves per game and there
    are at most N possible intersections per move. (The sign ** is
    a text file notation for "to the power".) -
    Extremely modest estimates look like 10**N, which is based on
    an assumption of 10 reasonable intersections per move. A
    popular estimate for 19x19 go is 10**761, which must have
    originated from a typo and should be 10**361, if at all...
    These types of estimates are so popular because humans cannot
    even imagine the suggested number of atoms in the universe,
    10**80. For comparison, 3**361 is ca. 10**172.

    6 TOURNAMENT RULES

    6.1 Special Game Ends

    If the score considering the komi is zero, then the game is a
    tie and should be treated as 0.5 won games for each. Special
    rules or undue behaviour like sincere lateness might result
    in a referee declaring a win by forfeit, 0:0, or 1:1,
    whichever is most appropriate.

    6.2 Tournament Systems

    A tournament might consist of several stages, of which each
    has a seed and a system. A seed appropriately restricts
    participation, e.g. due to qualification. The most important
    systems are match, league, knockout, Swiss, McMahon. There
    are many others and hybrids. A system must fit the aims of a
    tournament. A sufficient number of rounds, a proper seed,
    and colour variation ensure a fair determination of the best
    player. -
    A match takes place between two players that either play a
    set number of games to see who wins more or a maximal number
    of games to see who wins a predetermined number of games
    first. In a league a small, usually even number of players
    performs a round-robin tournament, so that in each round all
    players play and every two players play against each other,
    one game e.g. A knockout preferably starts with a number of
    players that is a power of two. Losing players are eliminated,
    winning players continue until the winner remains. -
    In a Swiss system before each round each player's achieved
    number of wins is used to pair players with equal numbers as
    far as possible. So all players play all rounds and some time
    the best player will emerge. However, with greatly varying
    strengths too many rounds would be needed. So Swiss is only
    useful for particular events or handicap tournaments.
    McMahon is the refinement of Swiss. Before the start of the
    tournament all players are classified in rank groups, with
    ranks R from 0 to T. This means that one assumes a preceding
    Swiss tournament where every player has already won R games.
    Then in the McMahon tournament the strongest players, who
    deserve the rank T, compete for the top places. In practice,
    one uses a bar B, that is 1 or 2 ranks below T, so that all
    ranks above B are contracted to B and also players slightly
    weaker than the top players get their chance. All players in
    a McMahon play roughly equal opponents; if they win or lose,
    then the opponents will be stronger or weaker.

    6.3 Tie Breakers

    Tie breakers can refine pairings or results. Typically the
    first criterion is the number of wins (or McMahon points);
    all further criteria, if any, are tie breakers. They attempt
    a refinement where a low number of rounds and a tournament
    system do not guarantee sufficient distinction between
    players' achievements. However, they must be applied with
    care since they are only marginally better than coin tossing.
    Examples of tie breakers are direct comparison, which
    acknowledges the winner of a game between two players in
    question, and SOS, which is the Sum of Opponents' Scores. -
    The possible degree of quality of tie breakers is subject to
    discussion. It depends on tournament system, whether only the
    top or all players shall be distinguished, and other factors.
    An alternative to the usage of tie breakers for the final
    results ordering is issuing shared places for all players
    with the same number of wins (or McMahon points). - One must
    fairly assign tie breaker points for opponents missing in
    some round; enforcing participation is preferable especially
    for top players.

    6.4 Pairing

    Pairings must be fair, precise, and consider prior
    achievements during a tournament. One should consider colour
    balance and no pair twice, one might also aim at avoiding a
    pair of players from the same club or country, depending on
    a tournament's intentions. Pairings might be done manually
    in small tournaments; for most tournaments pairing programs
    should be used. These can create fair pairings convincingly,
    some even watch global balance.

    6.5 Thinking Times

    The age of killing each other by greater endurance has gone.
    Clocks are used to count each player's remaining thinking
    time. Typically, every game has a basic time and overtime
    periods. Exceeding a time limit loses a game. Basic time
    might be 9 hours for a professional top game, 10 minutes for
    a lightning game, or something in between that fits a
    tournament's intentions. An overtime period requires a fixed
    number of moves within a predetermined period, e.g. 1 move
    within 60 seconds. A move is finished by pressing the clock.
    - Many variants or other time systems exist, e.g., increasing
    numbers of moves in further overtime periods, penalty points
    for entering further periods, full usage of every overtime
    period, thinking time working like an hour glass, etc.

    6.6 Tournament Rules

    Every tournament uses an announced set of tournament rules.
    They especially specify the used set for the core rules of
    play, the tournament system, tie breakers, the pairing
    method, the winning criteria, compensation methods,
    thinking times, direction, jurisdiction, adjournment
    methods, penalities for being late, etc. Tournament rules
    often deal with details. Not everything can be predicted, so
    a sportsmanlike spirit is mentioned. Finally, it should be
    clear which of several rule sets takes precedence.

    6.7 Tournament Organization

    A regional tournament can be organized by a club. Big events
    can be held at the request of an association or federation,
    who also supervise. A tournament organization is responsible
    for providing a venue and playing material. It must be
    distinguished from the tournament director and his assistant
    directors, who perform the particular tasks of pairing,
    collecting results, and ensuring smooth running. Shared
    power furthermore demands independent referees.

    6.8 Jurisdiction

    Before the start of a tournament valid instances of a
    jurisdiction as well as the persons to be referees must be
    clear. Typically, for a tournament itself there is one
    referee as the first instance and a body of three referees
    as the second instance. For very peculiar cases a federation
    could have a third and final instance. Some tournament rules
    replace the second instance by a single person, called chief
    referee; to avoid confusion he ought not to judge as the
    first instance. Players should respect the referees' tough
    job of mediation or decision; referees should seriously
    enforce the rules.

    6.9 Prizes

    The first places of a tournament invoke major prizes. E.g.
    the first, second, third places might get 3/6, 2/6, 1/6 of
    the available money. In a tournament with many weaker
    players it is a good idea to provide some prizes for all
    other players that win most rounds as well. While prizes can
    be money, books, trophies, etc., one should remember that
    money is most universally accepted and trophies serve the
    media better than the winners. -
    On a related topic, a side event lottery must give equal
    chances to all participants. This is only achieved by using
    one lot for each.

    7 Links

    Most rules information, links, short rules: http://home.snafu.de/jasiek/rules.html

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Robert Jasiek@21:1/5 to All on Tue Jun 12 11:14:07 2018
    Title: Rules FAQ
    Author: Robert Jasiek <jasiek@snafu.de>
    Frequency: monthly
    Last Update: 2017-10-13; First Day: 1999-04-12
    Distribution: rec.games.go
    Copyright: free non-commercial usage for promotion

    0 CONTENTS

    1 Purpose of this Paper
    2 Information for Beginners
    3 Important Concepts
    4 Particular Rules
    5 Troublesome Details
    6 Tournament Rules
    7 Links

    1 PURPOSE OF THIS PAPER

    This paper is a basic reference for important rules terms,
    rules, and tournament rules. Beginners should read
    especially Chapters 2 and 3, players Chapters 3 to 5,
    tournament players and organizers Chapter 6.

    2 INFORMATION FOR BEGINNERS
    2.1 What Must I Know as a Beginner?

    The game is played on a grid board. Typically it has 19x19
    intersections, but 9x9 are also fine. Two players compete.
    The first player uses black stones, the other white.

    The players alternate. A player may play or pass. Playing
    is putting one's own stone on an empty intersection and
    removing any surrounded opposing stones. To avoid
    cycles, a play may not recreate any prior configuration of
    all stones on the board.

    Two successive passes end the game. Then the player with
    more intersections wins. Intersections are his if only his
    stones occupy or surround them.

    2.2 Which Rules do I Need as a Beginner?

    You can play with short rules as in 2.1. Other rules may
    be different, but the game is the same, i. e. strategy,
    tactics, and the score do not change. Extremely rare
    exceptions confirm this rule.

    The winner can be determined by area or by territory.
    Either includes empty intersections surrounded only by own
    stones. While area adds intersections occupied by own
    stones, territory adds opposing prisoners instead.

    All rules, except short rules, have further phases after
    alternation and before scoring. Towards a game end it is
    often clear which stones will be removed. The additional
    phases allow the players to agree on which stones shall be
    removed. Thereby final removals do not require alternation.

    Whether you score by area or by territory or whether you
    remove by alternation or by agreement should mainly depend
    on which rules are used by people you play with.

    2.3 Which Rules Should I Teach?

    One possibility is to use a board with 9x9 intersections,
    short rules as in 2.1, and count each player's score by
    using a finger to scan the board for his intersections.

    3 IMPORTANT CONCEPTS

    While strategy and tactics virtually remain the same,
    concepts vary in different rules. However, the following
    gives a comprehensive overview on standard terms.

    3.1 Stone, String

    The physical device that colours one intersection in a
    play is a STONE. Two intersections of the board are
    ADJACENT if they have a line but no intersection between
    them. Two intersections with either black, white, or no
    stones on them are CONNECTED if they are adjacent or if
    there is a chain of adjacent intersections of their type
    between them. A REGION consists of an intersection and
    any intersections connected to it. A black or white
    region is called a STRING.

    3.2 Surrounded

    An intersection of one colour is SURROUNDED by another
    colour if each leaving path reaches the other colour first
    after the one colour. Hereby it can only be surrounded
    black by white, white by black, empty by black, or empty
    by white. A region can be surrounded. For strings there is
    an alternative notion of no liberty (or breath). A LIBERTY
    of a string is an empty intersection adjacent to it. Thus
    a string is surrounded if and only if it has no liberty.

    3.3 Removal, Suicide

    A removal empties the intersections of surrounded stones
    if there are any. Hereby removal of opposing stones is
    executed first, if necessary. Rules may either require or
    forbid removal of own stones. This is called suicide or no
    suicide. In practice, suicide might be used for so called ko
    fights or in capturing races.

    3.4 Capture, Prisoner

    Rules that score territory call a removal a capture
    because all removed stones are seriously kept as prisoners.

    3.5 Move, Play, Pass

    The players have alternate turns. On each turn a player makes
    a move that is either a play or a pass. A play places one's
    own stone on an empty intersection. It can then include
    removal of surrounded stones, if any. A pass merely continues
    alternation by giving the opponent the next turn.

    3.6 Compensation

    The first move advantage by black can be compensated by
    compensation points (komi) that are added to the white score
    after the game end. Komi can be adjusted by 0.5 to avoid
    ties. Today integer values for komi for 19x19 boards
    typically range between 5 and 7. For 13x13 boards one should
    use 8, for 9x9 boards 6; however, there is no real consensus
    for small board komi values yet. -
    A weaker player (black) can get the right to place an agreed
    number of compensation stones (handicap) before white's first
    play. Rules may allow free or fixed handicap. Free handicap
    does not apply any restriction. Fixed handicap requires
    traditional placement on set intersections.

    3.7 Phases

    Normally, a game consists of the phases alternation,
    agreement, scoring. A game stop is between alternation and
    agreement, the game end is between agreement and scoring,
    and after scoring both players accept the counted score as
    the result. The main part of the game is the alternation
    phase. Special rules are invoked after it. Typically, two
    successive passes in alternation are the game stop and start
    the agreement phase. In it the players may agree on strings
    to be removed. If they agree, then they remove those strings
    from the board; this ends the game. Sometimes they might
    disagree, then no strings are removed but alternation is
    resumed as if the last game stop did not occur.

    3.8 Recreation

    The position is the pattern of black and white stones on the
    board. Without extra rule a position might be repeated
    infinitely. The easiest rule to prohibit this says: A play
    may not recreate a position. This refers to positions after
    completion of plays, i.e. after possible removals. The rule
    is called "superko". -
    Some rules use concepts different from superko. They combine
    a "2-play rule" with a "long cycle rule". The first says:
    Two successive plays may not recreate a position. The second
    says: If a position is recreated after more than two moves,
    then the game ends either immediately or, as a variant, as
    soon as the players agree, with the result "without result".
    In practice the 2-play rule is sufficient for almost all
    cases. It handles the relevant standard pattern of two
    adjacent intersections. For superko this is just a special
    application.

    3.9 Scoring

    The score is the result after the game end as defined by
    the rules. There are two different scoring methods: area
    scoring and territory scoring. Rules use one of them. Both
    give the same result in almost all cases and both evaluate
    the difference of the black and the white scores. A player's
    AREA score is the sum of intersections with own stones and
    of empty intersections surrounded only by own stones. Simply
    speaking, a player's TERRITORY score is the sum of empty
    intersections surrounded only by own stones and of prisoners
    of opposing colour. With both scoring methods empty
    intersections that are not surrounded by either black or
    white are neutral.

    3.10 Counting

    A score must be determined by some mechanical procedure in
    practice; this is called counting. There are various methods.
    Some rules prescribe one. A possible method is to use one's
    finger to count point by point. Other methods rearrange a lot
    of stones on the board.

    4 PARTICULAR RULES

    Rules vary extremely. However, in practice they often give
    the same result.

    4.1 Short Rules

    Examples of short rules are the Simple Rules or the
    Tromp-Taylor rules. They have no game stop and no agreement.
    Both are superfluous since necessary removals may already be
    performed in the alternation. Two successive passes end the
    game that is scored then. Short rules use area scoring,
    superko, and suicide. Further settings are left for
    tournament rules.

    4.2 American Rules

    These are used by the American Go Association. They use
    situational superko, no suicide, and 7.5 komi. They permit
    free or fixed handicap. Their most remarkable feature is to
    allow one of area scoring or territory scoring. Herefore
    pass stones (one prisoner compensates each pass) and white
    moving last always ensure the same result, regardless of the
    applied scoring method.

    4.3 Chinese Rules

    These are used in continental China and sometimes in other
    countries. Area scoring and no suicide are used.

    4.3.1 Official Chinese Rules

    In practice, ko rules roughly amount to a 2-play rule and a
    long cycle rule. The mentioned superko is overridden. The
    counting is a sophisticated half counting, where empty
    intersections and then after rearrangements stones of one
    colour are added to be compared with half the non-neutral
    intersections. The komi as a half komi is 3.75. In full
    counting, counts and komi would be twice as big.

    4.3.2 Simplified Chinese Rules

    Positional superko is used. A counting method is not
    prescribed. The full komi should be 7.5.

    4.4 Japanese Rules

    The differences mainly affect handling of late game phases
    but often do not alter scores. Japanese rules use some
    traditional territory scoring that attempts to exclude so
    called sekis. No suicide applies. The core of the ko rules
    is a 2-play rule and a long cycle rule. Typically, komi is
    6.5. Fixed handicap should be used. The counting is a
    sophisticated rearrangement of empty intersections and
    filling-in of prisoners.

    4.4.1 Game Finishing Process

    A game finishes with the following process: 1) So called
    dame (neutral points) and defensive moves (necessary
    connections etc. due to occupied dame) are filled.
    2) The hypothetical analysis, which presumes perfect play,
    determines so called life or death of each string and the
    scoring intersections. 3) Without making any approach moves,
    dead stones are removed from scoring intersections and added
    to the prisoners. 4) The score is counted. (2) and (3) do not
    allow to play out life and death since actually filling
    intersections costs points in Japanese rules.

    4.4.2 Official Japanese Rules

    There are the Japanese 1989 Rules, which are used in Japan
    and elsewhere, and the World Amateur Go Championships Rules,
    which are used in some particular tournaments. Korean rules
    are similar to Japanese rules but have a very different text
    and differ in rare positions. Official Japanese rules are
    very incomplete and have messy late game phases. E.g., the
    Japanese 1989 Rules allow filling of dame during alternation,
    after it, or both and have a so called ko-pass-rule for the
    hypothetical analysis. Now professional Japanese rules are
    explained precisely by a rules expert's interpretation called
    "the Japanese 2003 Rules".

    4.4.3 Simplified Japanese Rules

    As a recent invention, they are not used yet. They are
    complete and have clear late game phases. Filling of dame is
    done during alternation.

    4.4.4 Verbal Japanese Rules

    They are used for informal games in many countries and
    undefined, except that the game finishing process is used.
    In a tournament without any official rules of play, disputes
    are not solved due to the rules but with a referee.

    4.5 Ing Rules

    Ing rules use area scoring, suicide, 8 komi with black
    winning ties, and free handicap.

    4.5.1 Official Ing Rules

    The ko rules are a mess but somehow resemble superko.
    Details could fill books. The late game phases are specified
    insufficiently. The peculiar counting method requires 180
    stones of each colour throughout the game, fills any stones
    on the board after the game end, and leaves exactly one
    empty intersection, which determines the winner. The
    official rules are used in professional Taiwanese and some
    sponsored tournaments. Taiwanese amateurs have their own
    rules.

    4.5.2 Simplified Ing Rules

    Positional superko is used. A counting method is not
    prescribed. The late game phases are specified clearly. The
    simplified rules are used in EGF tournaments that are said
    to use Ing rules.

    4.6 New Zealand Rules

    Area scoring, suicide, situational superko, 7 komi, and free
    handicap are used.

    4.7 Go Server Rules

    Every go server has its own and often complicated rules, if
    any, so they cannot be given in detail here. Concerning
    "IGS rules", territory scoring, no suicide, a 2-play rule,
    fixed handicap, three game stopping passes, and captures in
    an agreement phase are used. Details about agreements and
    long cycles are not specified and lead to adjourned games in
    case of doubt. Komi is suggested but may be altered. Counting
    is automatic. "Yahoo" has territory scoring, no suicide, a
    2-play rule, two game stopping passes; long cycles and
    disagreements are not handled properly. On "email servers"
    players must agree on any rules. -
    Typically territory scoring on a go server means that neither
    points in any sekis are excluded nor pass stones are used.
    Thus while the Japanese seki exception is abandoned,
    disagreements about removals may lead to games without result
    since playing out can cost points.

    4.8 International Rules

    The international mailing list go-rules has proposed
    international rules, however, none are adopted yet. The core
    rules of play shall be clear, complete, and correct.
    Currently alternative texts are offered for suicide,
    recreation, and scoring. Especially unification of scoring
    methods is advocated.

    4.9 EGF Rules

    The EGF uses the Simplified Ing Rules with 8 komi (black
    wins ties) in Ing sponsored tournaments and the Nihon Kiin
    1989 Rules with 6.5 komi in Japanese/Korean sponsored
    tournaments. If significantly the European Go Championship
    has both kinds of sponsors, then boards 1-16 use the Nihon
    Kiin 1989 Rules and boards 17+ the Simplified Ing Rules.
    However, time settings depend on ranks.

    5 TROUBLESOME DETAILS

    5.1 Colour Choice

    In even games typically the colours are randomly chosen. In
    handicap games black receives the handicap stones. -
    A manual method for randomly choosing colours is called
    nigiri. The older player hides a number of white stones
    taken from the bowl, the opponent takes one or two black
    stones to guess the parity, and the parity of the number of
    white stones is revealed. If the opponent guesses right,
    then he takes black, else he takes white.

    5.2 Pass Stones

    Some rules use pass stones. A passing player adds one own
    stone to the prisoners. As a consequence, captures before
    the game end can be resolved in alternation without any loss
    because any not answered approach move is compensated by one
    pass stone. With traditional territory scoring that uses no
    pass stones definition problems arise due to this missing
    option. Modern territory scoring or equivalence scoring use
    pass stones.

    5.3 Equivalence

    Area scoring and territory scoring are close because either
    intersections occupied by own stones or opposing prisoners
    are used. Essentially, every prisoner is a stone removed
    from some intersection. For area it scores one point less
    for the stone's player while for territory it scores one
    point more for his opponent. This is equal. Exact equality
    for the entire game must also consider passes by using pass
    stones and an equal number of moves by requiring white to
    pass last. This is done by equivalence scoring.

    5.4 Meaning of Agreement Removals

    Removals in an agreement phase under area scoring are fair
    because they may as well occur in alternation. Removing a
    stone due to agreement includes its then empty intersection
    and all adjacent empty intersections in the score. Removing
    a stone by means of alternation includes its then empty
    intersection and all adjacent newly occupied intersections
    in the score. -
    With traditional territory scoring this is not possible
    since stones on the board do not score. Thus final captures
    must occur after the game end due to attempted definitions
    in the rules.

    5.5 Practical Scoring Differences

    Since area scoring and modern territory scoring using pass
    stones are equal, correct play is the same for both. Apart
    from Japanese rules exceptions like not scoring empty
    intersections especially in asymmetrical coexistences or
    like a pass-for-ko-rule, traditional territory scoring can
    make a different winner in practically ca. every 10000th
    even game. This is so rare because of a parity feature
    combined with a scarcely odd number of intersections that
    are in coexistences but do not score for area at the game
    end. With area scoring a komi change from 1.5, 3.5, 5.5, ...
    to 2.5, 4.5, 6.5, ... almost always would not change the
    winner. So altough occupying the last empty intersections
    that would otherwise not score just before a game stop gains
    one point each, alternately doing so leaves a total
    advantage of at most one point. Due to the parity feature
    the player to get it is predetermined when this occupation
    starts. More importantly, one final ko is worth 1 point under
    traditional territory scoring but 2 or rarely 4 points under
    area scoring. Rare one-sided points in coexistences provide
    only area. Other practical differences are even rarer. Cute
    players include the stones in their endgame value counts
    during the middle of an area scoring game.

    5.6 Stone Scoring

    In ancient times stone scoring was popular. Only stones on
    the board are scored. Thus empty intersections surrounded by
    own stones are filled until necessary so called eyes remain.
    Disconnected stones require more eyes in total, the so
    called group tax.

    5.7 Old Ing Scoring

    Old Ing rules allowed fractional scores by assigning points
    to neutral empty regions due to the percentage of black and
    white stones surrounding every region.

    5.8 Primitive Rules

    They do not have passes. Alternation ends when a player
    loses due to no legal play. Games can be extremely long and
    include special strategies, so called pass fights. Primitive
    rules (also called no pass rules or Conway rules) can be
    useful in mathematics.

    5.9 Tradition

    Historically, exceptions arose, which some like as such
    especially together with Japanese style rules. So called
    sekis are excluded from the score. Special positions, termed
    precedents, have special rules. Modern Japanese rules have
    generalized a lot of them by a pass-for-ko-rule. After the
    game stop or after the game end and particularly in
    hypothetical play a stone captured in a possible 2-play cycle
    may not be recaptured unless before a pass is made that
    specifies the particular 2-play cycle.

    5.10 Positional / Situational Superko

    Positional superko prohibits a play that recreates a position.
    Situational superko refers to the situation, i.e. to the
    position together with the right to move. So a play is
    prohibited if it recreates a position while the same player
    has the right to move. In practice the differences are
    extremely rare.

    5.11 Handicap Recompensation

    With area scoring handicap stones beyond the first provide
    a potential extra area of one point per handicap stone. Komi
    for white may consider this. Recompensation, H-1 points for H
    handicap stones, is virtually only used together with
    American rules.

    5.12 Mathematics

    Go is a complete information game, i.e. at every move each
    player knows the entire game situation. Hence theoretically
    an algorithm could determine perfect play. However, due to
    the complexity of the game with N intersections, for which
    it is provably impossible to devise a polynomial time
    solution, perfect play or ideal komi are unknown. What one
    does know is that in a game without komi the first player wins
    or ties and that perfect play is independent of set komi. Many
    other propositions have been discovered, some of which
    describe the relation between area and territory scoring, solve
    tiny endgame positions or cyclical behaviour. -
    Go is a very complex game! According to John Tromp, the number
    of legal positions is:

    208168199381979984699478633344862770286522453884530548425 639456820927419612738015378525648451698519643907259916015 628128546089888314427129715319317557736620397247064840935

    For positional superko, no passes, and no resignation, the
    number of possible games is smaller than N**L(N) because L(N)
    also restricts the maximal number of moves per game and there
    are at most N possible intersections per move. (The sign ** is
    a text file notation for "to the power".) -
    Extremely modest estimates look like 10**N, which is based on
    an assumption of 10 reasonable intersections per move. A
    popular estimate for 19x19 go is 10**761, which must have
    originated from a typo and should be 10**361, if at all...
    These types of estimates are so popular because humans cannot
    even imagine the suggested number of atoms in the universe,
    10**80. For comparison, 3**361 is ca. 10**172.

    6 TOURNAMENT RULES

    6.1 Special Game Ends

    If the score considering the komi is zero, then the game is a
    tie and should be treated as 0.5 won games for each. Special
    rules or undue behaviour like sincere lateness might result
    in a referee declaring a win by forfeit, 0:0, or 1:1,
    whichever is most appropriate.

    6.2 Tournament Systems

    A tournament might consist of several stages, of which each
    has a seed and a system. A seed appropriately restricts
    participation, e.g. due to qualification. The most important
    systems are match, league, knockout, Swiss, McMahon. There
    are many others and hybrids. A system must fit the aims of a
    tournament. A sufficient number of rounds, a proper seed,
    and colour variation ensure a fair determination of the best
    player. -
    A match takes place between two players that either play a
    set number of games to see who wins more or a maximal number
    of games to see who wins a predetermined number of games
    first. In a league a small, usually even number of players
    performs a round-robin tournament, so that in each round all
    players play and every two players play against each other,
    one game e.g. A knockout preferably starts with a number of
    players that is a power of two. Losing players are eliminated,
    winning players continue until the winner remains. -
    In a Swiss system before each round each player's achieved
    number of wins is used to pair players with equal numbers as
    far as possible. So all players play all rounds and some time
    the best player will emerge. However, with greatly varying
    strengths too many rounds would be needed. So Swiss is only
    useful for particular events or handicap tournaments.
    McMahon is the refinement of Swiss. Before the start of the
    tournament all players are classified in rank groups, with
    ranks R from 0 to T. This means that one assumes a preceding
    Swiss tournament where every player has already won R games.
    Then in the McMahon tournament the strongest players, who
    deserve the rank T, compete for the top places. In practice,
    one uses a bar B, that is 1 or 2 ranks below T, so that all
    ranks above B are contracted to B and also players slightly
    weaker than the top players get their chance. All players in
    a McMahon play roughly equal opponents; if they win or lose,
    then the opponents will be stronger or weaker.

    6.3 Tie Breakers

    Tie breakers can refine pairings or results. Typically the
    first criterion is the number of wins (or McMahon points);
    all further criteria, if any, are tie breakers. They attempt
    a refinement where a low number of rounds and a tournament
    system do not guarantee sufficient distinction between
    players' achievements. However, they must be applied with
    care since they are only marginally better than coin tossing.
    Examples of tie breakers are direct comparison, which
    acknowledges the winner of a game between two players in
    question, and SOS, which is the Sum of Opponents' Scores. -
    The possible degree of quality of tie breakers is subject to
    discussion. It depends on tournament system, whether only the
    top or all players shall be distinguished, and other factors.
    An alternative to the usage of tie breakers for the final
    results ordering is issuing shared places for all players
    with the same number of wins (or McMahon points). - One must
    fairly assign tie breaker points for opponents missing in
    some round; enforcing participation is preferable especially
    for top players.

    6.4 Pairing

    Pairings must be fair, precise, and consider prior
    achievements during a tournament. One should consider colour
    balance and no pair twice, one might also aim at avoiding a
    pair of players from the same club or country, depending on
    a tournament's intentions. Pairings might be done manually
    in small tournaments; for most tournaments pairing programs
    should be used. These can create fair pairings convincingly,
    some even watch global balance.

    6.5 Thinking Times

    The age of killing each other by greater endurance has gone.
    Clocks are used to count each player's remaining thinking
    time. Typically, every game has a basic time and overtime
    periods. Exceeding a time limit loses a game. Basic time
    might be 9 hours for a professional top game, 10 minutes for
    a lightning game, or something in between that fits a
    tournament's intentions. An overtime period requires a fixed
    number of moves within a predetermined period, e.g. 1 move
    within 60 seconds. A move is finished by pressing the clock.
    - Many variants or other time systems exist, e.g., increasing
    numbers of moves in further overtime periods, penalty points
    for entering further periods, full usage of every overtime
    period, thinking time working like an hour glass, etc.

    6.6 Tournament Rules

    Every tournament uses an announced set of tournament rules.
    They especially specify the used set for the core rules of
    play, the tournament system, tie breakers, the pairing
    method, the winning criteria, compensation methods,
    thinking times, direction, jurisdiction, adjournment
    methods, penalities for being late, etc. Tournament rules
    often deal with details. Not everything can be predicted, so
    a sportsmanlike spirit is mentioned. Finally, it should be
    clear which of several rule sets takes precedence.

    6.7 Tournament Organization

    A regional tournament can be organized by a club. Big events
    can be held at the request of an association or federation,
    who also supervise. A tournament organization is responsible
    for providing a venue and playing material. It must be
    distinguished from the tournament director and his assistant
    directors, who perform the particular tasks of pairing,
    collecting results, and ensuring smooth running. Shared
    power furthermore demands independent referees.

    6.8 Jurisdiction

    Before the start of a tournament valid instances of a
    jurisdiction as well as the persons to be referees must be
    clear. Typically, for a tournament itself there is one
    referee as the first instance and a body of three referees
    as the second instance. For very peculiar cases a federation
    could have a third and final instance. Some tournament rules
    replace the second instance by a single person, called chief
    referee; to avoid confusion he ought not to judge as the
    first instance. Players should respect the referees' tough
    job of mediation or decision; referees should seriously
    enforce the rules.

    6.9 Prizes

    The first places of a tournament invoke major prizes. E.g.
    the first, second, third places might get 3/6, 2/6, 1/6 of
    the available money. In a tournament with many weaker
    players it is a good idea to provide some prizes for all
    other players that win most rounds as well. While prizes can
    be money, books, trophies, etc., one should remember that
    money is most universally accepted and trophies serve the
    media better than the winners. -
    On a related topic, a side event lottery must give equal
    chances to all participants. This is only achieved by using
    one lot for each.

    7 Links

    Most rules information, links, short rules: http://home.snafu.de/jasiek/rules.html

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Robert Jasiek@21:1/5 to All on Thu Jul 12 07:27:09 2018
    Title: Rules FAQ
    Author: Robert Jasiek <jasiek@snafu.de>
    Frequency: monthly
    Last Update: 2017-10-13; First Day: 1999-04-12
    Distribution: rec.games.go
    Copyright: free non-commercial usage for promotion

    0 CONTENTS

    1 Purpose of this Paper
    2 Information for Beginners
    3 Important Concepts
    4 Particular Rules
    5 Troublesome Details
    6 Tournament Rules
    7 Links

    1 PURPOSE OF THIS PAPER

    This paper is a basic reference for important rules terms,
    rules, and tournament rules. Beginners should read
    especially Chapters 2 and 3, players Chapters 3 to 5,
    tournament players and organizers Chapter 6.

    2 INFORMATION FOR BEGINNERS
    2.1 What Must I Know as a Beginner?

    The game is played on a grid board. Typically it has 19x19
    intersections, but 9x9 are also fine. Two players compete.
    The first player uses black stones, the other white.

    The players alternate. A player may play or pass. Playing
    is putting one's own stone on an empty intersection and
    removing any surrounded opposing stones. To avoid
    cycles, a play may not recreate any prior configuration of
    all stones on the board.

    Two successive passes end the game. Then the player with
    more intersections wins. Intersections are his if only his
    stones occupy or surround them.

    2.2 Which Rules do I Need as a Beginner?

    You can play with short rules as in 2.1. Other rules may
    be different, but the game is the same, i. e. strategy,
    tactics, and the score do not change. Extremely rare
    exceptions confirm this rule.

    The winner can be determined by area or by territory.
    Either includes empty intersections surrounded only by own
    stones. While area adds intersections occupied by own
    stones, territory adds opposing prisoners instead.

    All rules, except short rules, have further phases after
    alternation and before scoring. Towards a game end it is
    often clear which stones will be removed. The additional
    phases allow the players to agree on which stones shall be
    removed. Thereby final removals do not require alternation.

    Whether you score by area or by territory or whether you
    remove by alternation or by agreement should mainly depend
    on which rules are used by people you play with.

    2.3 Which Rules Should I Teach?

    One possibility is to use a board with 9x9 intersections,
    short rules as in 2.1, and count each player's score by
    using a finger to scan the board for his intersections.

    3 IMPORTANT CONCEPTS

    While strategy and tactics virtually remain the same,
    concepts vary in different rules. However, the following
    gives a comprehensive overview on standard terms.

    3.1 Stone, String

    The physical device that colours one intersection in a
    play is a STONE. Two intersections of the board are
    ADJACENT if they have a line but no intersection between
    them. Two intersections with either black, white, or no
    stones on them are CONNECTED if they are adjacent or if
    there is a chain of adjacent intersections of their type
    between them. A REGION consists of an intersection and
    any intersections connected to it. A black or white
    region is called a STRING.

    3.2 Surrounded

    An intersection of one colour is SURROUNDED by another
    colour if each leaving path reaches the other colour first
    after the one colour. Hereby it can only be surrounded
    black by white, white by black, empty by black, or empty
    by white. A region can be surrounded. For strings there is
    an alternative notion of no liberty (or breath). A LIBERTY
    of a string is an empty intersection adjacent to it. Thus
    a string is surrounded if and only if it has no liberty.

    3.3 Removal, Suicide

    A removal empties the intersections of surrounded stones
    if there are any. Hereby removal of opposing stones is
    executed first, if necessary. Rules may either require or
    forbid removal of own stones. This is called suicide or no
    suicide. In practice, suicide might be used for so called ko
    fights or in capturing races.

    3.4 Capture, Prisoner

    Rules that score territory call a removal a capture
    because all removed stones are seriously kept as prisoners.

    3.5 Move, Play, Pass

    The players have alternate turns. On each turn a player makes
    a move that is either a play or a pass. A play places one's
    own stone on an empty intersection. It can then include
    removal of surrounded stones, if any. A pass merely continues
    alternation by giving the opponent the next turn.

    3.6 Compensation

    The first move advantage by black can be compensated by
    compensation points (komi) that are added to the white score
    after the game end. Komi can be adjusted by 0.5 to avoid
    ties. Today integer values for komi for 19x19 boards
    typically range between 5 and 7. For 13x13 boards one should
    use 8, for 9x9 boards 6; however, there is no real consensus
    for small board komi values yet. -
    A weaker player (black) can get the right to place an agreed
    number of compensation stones (handicap) before white's first
    play. Rules may allow free or fixed handicap. Free handicap
    does not apply any restriction. Fixed handicap requires
    traditional placement on set intersections.

    3.7 Phases

    Normally, a game consists of the phases alternation,
    agreement, scoring. A game stop is between alternation and
    agreement, the game end is between agreement and scoring,
    and after scoring both players accept the counted score as
    the result. The main part of the game is the alternation
    phase. Special rules are invoked after it. Typically, two
    successive passes in alternation are the game stop and start
    the agreement phase. In it the players may agree on strings
    to be removed. If they agree, then they remove those strings
    from the board; this ends the game. Sometimes they might
    disagree, then no strings are removed but alternation is
    resumed as if the last game stop did not occur.

    3.8 Recreation

    The position is the pattern of black and white stones on the
    board. Without extra rule a position might be repeated
    infinitely. The easiest rule to prohibit this says: A play
    may not recreate a position. This refers to positions after
    completion of plays, i.e. after possible removals. The rule
    is called "superko". -
    Some rules use concepts different from superko. They combine
    a "2-play rule" with a "long cycle rule". The first says:
    Two successive plays may not recreate a position. The second
    says: If a position is recreated after more than two moves,
    then the game ends either immediately or, as a variant, as
    soon as the players agree, with the result "without result".
    In practice the 2-play rule is sufficient for almost all
    cases. It handles the relevant standard pattern of two
    adjacent intersections. For superko this is just a special
    application.

    3.9 Scoring

    The score is the result after the game end as defined by
    the rules. There are two different scoring methods: area
    scoring and territory scoring. Rules use one of them. Both
    give the same result in almost all cases and both evaluate
    the difference of the black and the white scores. A player's
    AREA score is the sum of intersections with own stones and
    of empty intersections surrounded only by own stones. Simply
    speaking, a player's TERRITORY score is the sum of empty
    intersections surrounded only by own stones and of prisoners
    of opposing colour. With both scoring methods empty
    intersections that are not surrounded by either black or
    white are neutral.

    3.10 Counting

    A score must be determined by some mechanical procedure in
    practice; this is called counting. There are various methods.
    Some rules prescribe one. A possible method is to use one's
    finger to count point by point. Other methods rearrange a lot
    of stones on the board.

    4 PARTICULAR RULES

    Rules vary extremely. However, in practice they often give
    the same result.

    4.1 Short Rules

    Examples of short rules are the Simple Rules or the
    Tromp-Taylor rules. They have no game stop and no agreement.
    Both are superfluous since necessary removals may already be
    performed in the alternation. Two successive passes end the
    game that is scored then. Short rules use area scoring,
    superko, and suicide. Further settings are left for
    tournament rules.

    4.2 American Rules

    These are used by the American Go Association. They use
    situational superko, no suicide, and 7.5 komi. They permit
    free or fixed handicap. Their most remarkable feature is to
    allow one of area scoring or territory scoring. Herefore
    pass stones (one prisoner compensates each pass) and white
    moving last always ensure the same result, regardless of the
    applied scoring method.

    4.3 Chinese Rules

    These are used in continental China and sometimes in other
    countries. Area scoring and no suicide are used.

    4.3.1 Official Chinese Rules

    In practice, ko rules roughly amount to a 2-play rule and a
    long cycle rule. The mentioned superko is overridden. The
    counting is a sophisticated half counting, where empty
    intersections and then after rearrangements stones of one
    colour are added to be compared with half the non-neutral
    intersections. The komi as a half komi is 3.75. In full
    counting, counts and komi would be twice as big.

    4.3.2 Simplified Chinese Rules

    Positional superko is used. A counting method is not
    prescribed. The full komi should be 7.5.

    4.4 Japanese Rules

    The differences mainly affect handling of late game phases
    but often do not alter scores. Japanese rules use some
    traditional territory scoring that attempts to exclude so
    called sekis. No suicide applies. The core of the ko rules
    is a 2-play rule and a long cycle rule. Typically, komi is
    6.5. Fixed handicap should be used. The counting is a
    sophisticated rearrangement of empty intersections and
    filling-in of prisoners.

    4.4.1 Game Finishing Process

    A game finishes with the following process: 1) So called
    dame (neutral points) and defensive moves (necessary
    connections etc. due to occupied dame) are filled.
    2) The hypothetical analysis, which presumes perfect play,
    determines so called life or death of each string and the
    scoring intersections. 3) Without making any approach moves,
    dead stones are removed from scoring intersections and added
    to the prisoners. 4) The score is counted. (2) and (3) do not
    allow to play out life and death since actually filling
    intersections costs points in Japanese rules.

    4.4.2 Official Japanese Rules

    There are the Japanese 1989 Rules, which are used in Japan
    and elsewhere, and the World Amateur Go Championships Rules,
    which are used in some particular tournaments. Korean rules
    are similar to Japanese rules but have a very different text
    and differ in rare positions. Official Japanese rules are
    very incomplete and have messy late game phases. E.g., the
    Japanese 1989 Rules allow filling of dame during alternation,
    after it, or both and have a so called ko-pass-rule for the
    hypothetical analysis. Now professional Japanese rules are
    explained precisely by a rules expert's interpretation called
    "the Japanese 2003 Rules".

    4.4.3 Simplified Japanese Rules

    As a recent invention, they are not used yet. They are
    complete and have clear late game phases. Filling of dame is
    done during alternation.

    4.4.4 Verbal Japanese Rules

    They are used for informal games in many countries and
    undefined, except that the game finishing process is used.
    In a tournament without any official rules of play, disputes
    are not solved due to the rules but with a referee.

    4.5 Ing Rules

    Ing rules use area scoring, suicide, 8 komi with black
    winning ties, and free handicap.

    4.5.1 Official Ing Rules

    The ko rules are a mess but somehow resemble superko.
    Details could fill books. The late game phases are specified
    insufficiently. The peculiar counting method requires 180
    stones of each colour throughout the game, fills any stones
    on the board after the game end, and leaves exactly one
    empty intersection, which determines the winner. The
    official rules are used in professional Taiwanese and some
    sponsored tournaments. Taiwanese amateurs have their own
    rules.

    4.5.2 Simplified Ing Rules

    Positional superko is used. A counting method is not
    prescribed. The late game phases are specified clearly. The
    simplified rules are used in EGF tournaments that are said
    to use Ing rules.

    4.6 New Zealand Rules

    Area scoring, suicide, situational superko, 7 komi, and free
    handicap are used.

    4.7 Go Server Rules

    Every go server has its own and often complicated rules, if
    any, so they cannot be given in detail here. Concerning
    "IGS rules", territory scoring, no suicide, a 2-play rule,
    fixed handicap, three game stopping passes, and captures in
    an agreement phase are used. Details about agreements and
    long cycles are not specified and lead to adjourned games in
    case of doubt. Komi is suggested but may be altered. Counting
    is automatic. "Yahoo" has territory scoring, no suicide, a
    2-play rule, two game stopping passes; long cycles and
    disagreements are not handled properly. On "email servers"
    players must agree on any rules. -
    Typically territory scoring on a go server means that neither
    points in any sekis are excluded nor pass stones are used.
    Thus while the Japanese seki exception is abandoned,
    disagreements about removals may lead to games without result
    since playing out can cost points.

    4.8 International Rules

    The international mailing list go-rules has proposed
    international rules, however, none are adopted yet. The core
    rules of play shall be clear, complete, and correct.
    Currently alternative texts are offered for suicide,
    recreation, and scoring. Especially unification of scoring
    methods is advocated.

    4.9 EGF Rules

    The EGF uses the Simplified Ing Rules with 8 komi (black
    wins ties) in Ing sponsored tournaments and the Nihon Kiin
    1989 Rules with 6.5 komi in Japanese/Korean sponsored
    tournaments. If significantly the European Go Championship
    has both kinds of sponsors, then boards 1-16 use the Nihon
    Kiin 1989 Rules and boards 17+ the Simplified Ing Rules.
    However, time settings depend on ranks.

    5 TROUBLESOME DETAILS

    5.1 Colour Choice

    In even games typically the colours are randomly chosen. In
    handicap games black receives the handicap stones. -
    A manual method for randomly choosing colours is called
    nigiri. The older player hides a number of white stones
    taken from the bowl, the opponent takes one or two black
    stones to guess the parity, and the parity of the number of
    white stones is revealed. If the opponent guesses right,
    then he takes black, else he takes white.

    5.2 Pass Stones

    Some rules use pass stones. A passing player adds one own
    stone to the prisoners. As a consequence, captures before
    the game end can be resolved in alternation without any loss
    because any not answered approach move is compensated by one
    pass stone. With traditional territory scoring that uses no
    pass stones definition problems arise due to this missing
    option. Modern territory scoring or equivalence scoring use
    pass stones.

    5.3 Equivalence

    Area scoring and territory scoring are close because either
    intersections occupied by own stones or opposing prisoners
    are used. Essentially, every prisoner is a stone removed
    from some intersection. For area it scores one point less
    for the stone's player while for territory it scores one
    point more for his opponent. This is equal. Exact equality
    for the entire game must also consider passes by using pass
    stones and an equal number of moves by requiring white to
    pass last. This is done by equivalence scoring.

    5.4 Meaning of Agreement Removals

    Removals in an agreement phase under area scoring are fair
    because they may as well occur in alternation. Removing a
    stone due to agreement includes its then empty intersection
    and all adjacent empty intersections in the score. Removing
    a stone by means of alternation includes its then empty
    intersection and all adjacent newly occupied intersections
    in the score. -
    With traditional territory scoring this is not possible
    since stones on the board do not score. Thus final captures
    must occur after the game end due to attempted definitions
    in the rules.

    5.5 Practical Scoring Differences

    Since area scoring and modern territory scoring using pass
    stones are equal, correct play is the same for both. Apart
    from Japanese rules exceptions like not scoring empty
    intersections especially in asymmetrical coexistences or
    like a pass-for-ko-rule, traditional territory scoring can
    make a different winner in practically ca. every 10000th
    even game. This is so rare because of a parity feature
    combined with a scarcely odd number of intersections that
    are in coexistences but do not score for area at the game
    end. With area scoring a komi change from 1.5, 3.5, 5.5, ...
    to 2.5, 4.5, 6.5, ... almost always would not change the
    winner. So altough occupying the last empty intersections
    that would otherwise not score just before a game stop gains
    one point each, alternately doing so leaves a total
    advantage of at most one point. Due to the parity feature
    the player to get it is predetermined when this occupation
    starts. More importantly, one final ko is worth 1 point under
    traditional territory scoring but 2 or rarely 4 points under
    area scoring. Rare one-sided points in coexistences provide
    only area. Other practical differences are even rarer. Cute
    players include the stones in their endgame value counts
    during the middle of an area scoring game.

    5.6 Stone Scoring

    In ancient times stone scoring was popular. Only stones on
    the board are scored. Thus empty intersections surrounded by
    own stones are filled until necessary so called eyes remain.
    Disconnected stones require more eyes in total, the so
    called group tax.

    5.7 Old Ing Scoring

    Old Ing rules allowed fractional scores by assigning points
    to neutral empty regions due to the percentage of black and
    white stones surrounding every region.

    5.8 Primitive Rules

    They do not have passes. Alternation ends when a player
    loses due to no legal play. Games can be extremely long and
    include special strategies, so called pass fights. Primitive
    rules (also called no pass rules or Conway rules) can be
    useful in mathematics.

    5.9 Tradition

    Historically, exceptions arose, which some like as such
    especially together with Japanese style rules. So called
    sekis are excluded from the score. Special positions, termed
    precedents, have special rules. Modern Japanese rules have
    generalized a lot of them by a pass-for-ko-rule. After the
    game stop or after the game end and particularly in
    hypothetical play a stone captured in a possible 2-play cycle
    may not be recaptured unless before a pass is made that
    specifies the particular 2-play cycle.

    5.10 Positional / Situational Superko

    Positional superko prohibits a play that recreates a position.
    Situational superko refers to the situation, i.e. to the
    position together with the right to move. So a play is
    prohibited if it recreates a position while the same player
    has the right to move. In practice the differences are
    extremely rare.

    5.11 Handicap Recompensation

    With area scoring handicap stones beyond the first provide
    a potential extra area of one point per handicap stone. Komi
    for white may consider this. Recompensation, H-1 points for H
    handicap stones, is virtually only used together with
    American rules.

    5.12 Mathematics

    Go is a complete information game, i.e. at every move each
    player knows the entire game situation. Hence theoretically
    an algorithm could determine perfect play. However, due to
    the complexity of the game with N intersections, for which
    it is provably impossible to devise a polynomial time
    solution, perfect play or ideal komi are unknown. What one
    does know is that in a game without komi the first player wins
    or ties and that perfect play is independent of set komi. Many
    other propositions have been discovered, some of which
    describe the relation between area and territory scoring, solve
    tiny endgame positions or cyclical behaviour. -
    Go is a very complex game! According to John Tromp, the number
    of legal positions is:

    208168199381979984699478633344862770286522453884530548425 639456820927419612738015378525648451698519643907259916015 628128546089888314427129715319317557736620397247064840935

    For positional superko, no passes, and no resignation, the
    number of possible games is smaller than N**L(N) because L(N)
    also restricts the maximal number of moves per game and there
    are at most N possible intersections per move. (The sign ** is
    a text file notation for "to the power".) -
    Extremely modest estimates look like 10**N, which is based on
    an assumption of 10 reasonable intersections per move. A
    popular estimate for 19x19 go is 10**761, which must have
    originated from a typo and should be 10**361, if at all...
    These types of estimates are so popular because humans cannot
    even imagine the suggested number of atoms in the universe,
    10**80. For comparison, 3**361 is ca. 10**172.

    6 TOURNAMENT RULES

    6.1 Special Game Ends

    If the score considering the komi is zero, then the game is a
    tie and should be treated as 0.5 won games for each. Special
    rules or undue behaviour like sincere lateness might result
    in a referee declaring a win by forfeit, 0:0, or 1:1,
    whichever is most appropriate.

    6.2 Tournament Systems

    A tournament might consist of several stages, of which each
    has a seed and a system. A seed appropriately restricts
    participation, e.g. due to qualification. The most important
    systems are match, league, knockout, Swiss, McMahon. There
    are many others and hybrids. A system must fit the aims of a
    tournament. A sufficient number of rounds, a proper seed,
    and colour variation ensure a fair determination of the best
    player. -
    A match takes place between two players that either play a
    set number of games to see who wins more or a maximal number
    of games to see who wins a predetermined number of games
    first. In a league a small, usually even number of players
    performs a round-robin tournament, so that in each round all
    players play and every two players play against each other,
    one game e.g. A knockout preferably starts with a number of
    players that is a power of two. Losing players are eliminated,
    winning players continue until the winner remains. -
    In a Swiss system before each round each player's achieved
    number of wins is used to pair players with equal numbers as
    far as possible. So all players play all rounds and some time
    the best player will emerge. However, with greatly varying
    strengths too many rounds would be needed. So Swiss is only
    useful for particular events or handicap tournaments.
    McMahon is the refinement of Swiss. Before the start of the
    tournament all players are classified in rank groups, with
    ranks R from 0 to T. This means that one assumes a preceding
    Swiss tournament where every player has already won R games.
    Then in the McMahon tournament the strongest players, who
    deserve the rank T, compete for the top places. In practice,
    one uses a bar B, that is 1 or 2 ranks below T, so that all
    ranks above B are contracted to B and also players slightly
    weaker than the top players get their chance. All players in
    a McMahon play roughly equal opponents; if they win or lose,
    then the opponents will be stronger or weaker.

    6.3 Tie Breakers

    Tie breakers can refine pairings or results. Typically the
    first criterion is the number of wins (or McMahon points);
    all further criteria, if any, are tie breakers. They attempt
    a refinement where a low number of rounds and a tournament
    system do not guarantee sufficient distinction between
    players' achievements. However, they must be applied with
    care since they are only marginally better than coin tossing.
    Examples of tie breakers are direct comparison, which
    acknowledges the winner of a game between two players in
    question, and SOS, which is the Sum of Opponents' Scores. -
    The possible degree of quality of tie breakers is subject to
    discussion. It depends on tournament system, whether only the
    top or all players shall be distinguished, and other factors.
    An alternative to the usage of tie breakers for the final
    results ordering is issuing shared places for all players
    with the same number of wins (or McMahon points). - One must
    fairly assign tie breaker points for opponents missing in
    some round; enforcing participation is preferable especially
    for top players.

    6.4 Pairing

    Pairings must be fair, precise, and consider prior
    achievements during a tournament. One should consider colour
    balance and no pair twice, one might also aim at avoiding a
    pair of players from the same club or country, depending on
    a tournament's intentions. Pairings might be done manually
    in small tournaments; for most tournaments pairing programs
    should be used. These can create fair pairings convincingly,
    some even watch global balance.

    6.5 Thinking Times

    The age of killing each other by greater endurance has gone.
    Clocks are used to count each player's remaining thinking
    time. Typically, every game has a basic time and overtime
    periods. Exceeding a time limit loses a game. Basic time
    might be 9 hours for a professional top game, 10 minutes for
    a lightning game, or something in between that fits a
    tournament's intentions. An overtime period requires a fixed
    number of moves within a predetermined period, e.g. 1 move
    within 60 seconds. A move is finished by pressing the clock.
    - Many variants or other time systems exist, e.g., increasing
    numbers of moves in further overtime periods, penalty points
    for entering further periods, full usage of every overtime
    period, thinking time working like an hour glass, etc.

    6.6 Tournament Rules

    Every tournament uses an announced set of tournament rules.
    They especially specify the used set for the core rules of
    play, the tournament system, tie breakers, the pairing
    method, the winning criteria, compensation methods,
    thinking times, direction, jurisdiction, adjournment
    methods, penalities for being late, etc. Tournament rules
    often deal with details. Not everything can be predicted, so
    a sportsmanlike spirit is mentioned. Finally, it should be
    clear which of several rule sets takes precedence.

    6.7 Tournament Organization

    A regional tournament can be organized by a club. Big events
    can be held at the request of an association or federation,
    who also supervise. A tournament organization is responsible
    for providing a venue and playing material. It must be
    distinguished from the tournament director and his assistant
    directors, who perform the particular tasks of pairing,
    collecting results, and ensuring smooth running. Shared
    power furthermore demands independent referees.

    6.8 Jurisdiction

    Before the start of a tournament valid instances of a
    jurisdiction as well as the persons to be referees must be
    clear. Typically, for a tournament itself there is one
    referee as the first instance and a body of three referees
    as the second instance. For very peculiar cases a federation
    could have a third and final instance. Some tournament rules
    replace the second instance by a single person, called chief
    referee; to avoid confusion he ought not to judge as the
    first instance. Players should respect the referees' tough
    job of mediation or decision; referees should seriously
    enforce the rules.

    6.9 Prizes

    The first places of a tournament invoke major prizes. E.g.
    the first, second, third places might get 3/6, 2/6, 1/6 of
    the available money. In a tournament with many weaker
    players it is a good idea to provide some prizes for all
    other players that win most rounds as well. While prizes can
    be money, books, trophies, etc., one should remember that
    money is most universally accepted and trophies serve the
    media better than the winners. -
    On a related topic, a side event lottery must give equal
    chances to all participants. This is only achieved by using
    one lot for each.

    7 Links

    Most rules information, links, short rules: http://home.snafu.de/jasiek/rules.html

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Robert Jasiek@21:1/5 to All on Wed Sep 12 07:39:08 2018
    Title: Rules FAQ
    Author: Robert Jasiek <jasiek@snafu.de>
    Frequency: monthly
    Last Update: 2017-10-13; First Day: 1999-04-12
    Distribution: rec.games.go
    Copyright: free non-commercial usage for promotion

    0 CONTENTS

    1 Purpose of this Paper
    2 Information for Beginners
    3 Important Concepts
    4 Particular Rules
    5 Troublesome Details
    6 Tournament Rules
    7 Links

    1 PURPOSE OF THIS PAPER

    This paper is a basic reference for important rules terms,
    rules, and tournament rules. Beginners should read
    especially Chapters 2 and 3, players Chapters 3 to 5,
    tournament players and organizers Chapter 6.

    2 INFORMATION FOR BEGINNERS
    2.1 What Must I Know as a Beginner?

    The game is played on a grid board. Typically it has 19x19
    intersections, but 9x9 are also fine. Two players compete.
    The first player uses black stones, the other white.

    The players alternate. A player may play or pass. Playing
    is putting one's own stone on an empty intersection and
    removing any surrounded opposing stones. To avoid
    cycles, a play may not recreate any prior configuration of
    all stones on the board.

    Two successive passes end the game. Then the player with
    more intersections wins. Intersections are his if only his
    stones occupy or surround them.

    2.2 Which Rules do I Need as a Beginner?

    You can play with short rules as in 2.1. Other rules may
    be different, but the game is the same, i. e. strategy,
    tactics, and the score do not change. Extremely rare
    exceptions confirm this rule.

    The winner can be determined by area or by territory.
    Either includes empty intersections surrounded only by own
    stones. While area adds intersections occupied by own
    stones, territory adds opposing prisoners instead.

    All rules, except short rules, have further phases after
    alternation and before scoring. Towards a game end it is
    often clear which stones will be removed. The additional
    phases allow the players to agree on which stones shall be
    removed. Thereby final removals do not require alternation.

    Whether you score by area or by territory or whether you
    remove by alternation or by agreement should mainly depend
    on which rules are used by people you play with.

    2.3 Which Rules Should I Teach?

    One possibility is to use a board with 9x9 intersections,
    short rules as in 2.1, and count each player's score by
    using a finger to scan the board for his intersections.

    3 IMPORTANT CONCEPTS

    While strategy and tactics virtually remain the same,
    concepts vary in different rules. However, the following
    gives a comprehensive overview on standard terms.

    3.1 Stone, String

    The physical device that colours one intersection in a
    play is a STONE. Two intersections of the board are
    ADJACENT if they have a line but no intersection between
    them. Two intersections with either black, white, or no
    stones on them are CONNECTED if they are adjacent or if
    there is a chain of adjacent intersections of their type
    between them. A REGION consists of an intersection and
    any intersections connected to it. A black or white
    region is called a STRING.

    3.2 Surrounded

    An intersection of one colour is SURROUNDED by another
    colour if each leaving path reaches the other colour first
    after the one colour. Hereby it can only be surrounded
    black by white, white by black, empty by black, or empty
    by white. A region can be surrounded. For strings there is
    an alternative notion of no liberty (or breath). A LIBERTY
    of a string is an empty intersection adjacent to it. Thus
    a string is surrounded if and only if it has no liberty.

    3.3 Removal, Suicide

    A removal empties the intersections of surrounded stones
    if there are any. Hereby removal of opposing stones is
    executed first, if necessary. Rules may either require or
    forbid removal of own stones. This is called suicide or no
    suicide. In practice, suicide might be used for so called ko
    fights or in capturing races.

    3.4 Capture, Prisoner

    Rules that score territory call a removal a capture
    because all removed stones are seriously kept as prisoners.

    3.5 Move, Play, Pass

    The players have alternate turns. On each turn a player makes
    a move that is either a play or a pass. A play places one's
    own stone on an empty intersection. It can then include
    removal of surrounded stones, if any. A pass merely continues
    alternation by giving the opponent the next turn.

    3.6 Compensation

    The first move advantage by black can be compensated by
    compensation points (komi) that are added to the white score
    after the game end. Komi can be adjusted by 0.5 to avoid
    ties. Today integer values for komi for 19x19 boards
    typically range between 5 and 7. For 13x13 boards one should
    use 8, for 9x9 boards 6; however, there is no real consensus
    for small board komi values yet. -
    A weaker player (black) can get the right to place an agreed
    number of compensation stones (handicap) before white's first
    play. Rules may allow free or fixed handicap. Free handicap
    does not apply any restriction. Fixed handicap requires
    traditional placement on set intersections.

    3.7 Phases

    Normally, a game consists of the phases alternation,
    agreement, scoring. A game stop is between alternation and
    agreement, the game end is between agreement and scoring,
    and after scoring both players accept the counted score as
    the result. The main part of the game is the alternation
    phase. Special rules are invoked after it. Typically, two
    successive passes in alternation are the game stop and start
    the agreement phase. In it the players may agree on strings
    to be removed. If they agree, then they remove those strings
    from the board; this ends the game. Sometimes they might
    disagree, then no strings are removed but alternation is
    resumed as if the last game stop did not occur.

    3.8 Recreation

    The position is the pattern of black and white stones on the
    board. Without extra rule a position might be repeated
    infinitely. The easiest rule to prohibit this says: A play
    may not recreate a position. This refers to positions after
    completion of plays, i.e. after possible removals. The rule
    is called "superko". -
    Some rules use concepts different from superko. They combine
    a "2-play rule" with a "long cycle rule". The first says:
    Two successive plays may not recreate a position. The second
    says: If a position is recreated after more than two moves,
    then the game ends either immediately or, as a variant, as
    soon as the players agree, with the result "without result".
    In practice the 2-play rule is sufficient for almost all
    cases. It handles the relevant standard pattern of two
    adjacent intersections. For superko this is just a special
    application.

    3.9 Scoring

    The score is the result after the game end as defined by
    the rules. There are two different scoring methods: area
    scoring and territory scoring. Rules use one of them. Both
    give the same result in almost all cases and both evaluate
    the difference of the black and the white scores. A player's
    AREA score is the sum of intersections with own stones and
    of empty intersections surrounded only by own stones. Simply
    speaking, a player's TERRITORY score is the sum of empty
    intersections surrounded only by own stones and of prisoners
    of opposing colour. With both scoring methods empty
    intersections that are not surrounded by either black or
    white are neutral.

    3.10 Counting

    A score must be determined by some mechanical procedure in
    practice; this is called counting. There are various methods.
    Some rules prescribe one. A possible method is to use one's
    finger to count point by point. Other methods rearrange a lot
    of stones on the board.

    4 PARTICULAR RULES

    Rules vary extremely. However, in practice they often give
    the same result.

    4.1 Short Rules

    Examples of short rules are the Simple Rules or the
    Tromp-Taylor rules. They have no game stop and no agreement.
    Both are superfluous since necessary removals may already be
    performed in the alternation. Two successive passes end the
    game that is scored then. Short rules use area scoring,
    superko, and suicide. Further settings are left for
    tournament rules.

    4.2 American Rules

    These are used by the American Go Association. They use
    situational superko, no suicide, and 7.5 komi. They permit
    free or fixed handicap. Their most remarkable feature is to
    allow one of area scoring or territory scoring. Herefore
    pass stones (one prisoner compensates each pass) and white
    moving last always ensure the same result, regardless of the
    applied scoring method.

    4.3 Chinese Rules

    These are used in continental China and sometimes in other
    countries. Area scoring and no suicide are used.

    4.3.1 Official Chinese Rules

    In practice, ko rules roughly amount to a 2-play rule and a
    long cycle rule. The mentioned superko is overridden. The
    counting is a sophisticated half counting, where empty
    intersections and then after rearrangements stones of one
    colour are added to be compared with half the non-neutral
    intersections. The komi as a half komi is 3.75. In full
    counting, counts and komi would be twice as big.

    4.3.2 Simplified Chinese Rules

    Positional superko is used. A counting method is not
    prescribed. The full komi should be 7.5.

    4.4 Japanese Rules

    The differences mainly affect handling of late game phases
    but often do not alter scores. Japanese rules use some
    traditional territory scoring that attempts to exclude so
    called sekis. No suicide applies. The core of the ko rules
    is a 2-play rule and a long cycle rule. Typically, komi is
    6.5. Fixed handicap should be used. The counting is a
    sophisticated rearrangement of empty intersections and
    filling-in of prisoners.

    4.4.1 Game Finishing Process

    A game finishes with the following process: 1) So called
    dame (neutral points) and defensive moves (necessary
    connections etc. due to occupied dame) are filled.
    2) The hypothetical analysis, which presumes perfect play,
    determines so called life or death of each string and the
    scoring intersections. 3) Without making any approach moves,
    dead stones are removed from scoring intersections and added
    to the prisoners. 4) The score is counted. (2) and (3) do not
    allow to play out life and death since actually filling
    intersections costs points in Japanese rules.

    4.4.2 Official Japanese Rules

    There are the Japanese 1989 Rules, which are used in Japan
    and elsewhere, and the World Amateur Go Championships Rules,
    which are used in some particular tournaments. Korean rules
    are similar to Japanese rules but have a very different text
    and differ in rare positions. Official Japanese rules are
    very incomplete and have messy late game phases. E.g., the
    Japanese 1989 Rules allow filling of dame during alternation,
    after it, or both and have a so called ko-pass-rule for the
    hypothetical analysis. Now professional Japanese rules are
    explained precisely by a rules expert's interpretation called
    "the Japanese 2003 Rules".

    4.4.3 Simplified Japanese Rules

    As a recent invention, they are not used yet. They are
    complete and have clear late game phases. Filling of dame is
    done during alternation.

    4.4.4 Verbal Japanese Rules

    They are used for informal games in many countries and
    undefined, except that the game finishing process is used.
    In a tournament without any official rules of play, disputes
    are not solved due to the rules but with a referee.

    4.5 Ing Rules

    Ing rules use area scoring, suicide, 8 komi with black
    winning ties, and free handicap.

    4.5.1 Official Ing Rules

    The ko rules are a mess but somehow resemble superko.
    Details could fill books. The late game phases are specified
    insufficiently. The peculiar counting method requires 180
    stones of each colour throughout the game, fills any stones
    on the board after the game end, and leaves exactly one
    empty intersection, which determines the winner. The
    official rules are used in professional Taiwanese and some
    sponsored tournaments. Taiwanese amateurs have their own
    rules.

    4.5.2 Simplified Ing Rules

    Positional superko is used. A counting method is not
    prescribed. The late game phases are specified clearly. The
    simplified rules are used in EGF tournaments that are said
    to use Ing rules.

    4.6 New Zealand Rules

    Area scoring, suicide, situational superko, 7 komi, and free
    handicap are used.

    4.7 Go Server Rules

    Every go server has its own and often complicated rules, if
    any, so they cannot be given in detail here. Concerning
    "IGS rules", territory scoring, no suicide, a 2-play rule,
    fixed handicap, three game stopping passes, and captures in
    an agreement phase are used. Details about agreements and
    long cycles are not specified and lead to adjourned games in
    case of doubt. Komi is suggested but may be altered. Counting
    is automatic. "Yahoo" has territory scoring, no suicide, a
    2-play rule, two game stopping passes; long cycles and
    disagreements are not handled properly. On "email servers"
    players must agree on any rules. -
    Typically territory scoring on a go server means that neither
    points in any sekis are excluded nor pass stones are used.
    Thus while the Japanese seki exception is abandoned,
    disagreements about removals may lead to games without result
    since playing out can cost points.

    4.8 International Rules

    The international mailing list go-rules has proposed
    international rules, however, none are adopted yet. The core
    rules of play shall be clear, complete, and correct.
    Currently alternative texts are offered for suicide,
    recreation, and scoring. Especially unification of scoring
    methods is advocated.

    4.9 EGF Rules

    The EGF uses the Simplified Ing Rules with 8 komi (black
    wins ties) in Ing sponsored tournaments and the Nihon Kiin
    1989 Rules with 6.5 komi in Japanese/Korean sponsored
    tournaments. If significantly the European Go Championship
    has both kinds of sponsors, then boards 1-16 use the Nihon
    Kiin 1989 Rules and boards 17+ the Simplified Ing Rules.
    However, time settings depend on ranks.

    5 TROUBLESOME DETAILS

    5.1 Colour Choice

    In even games typically the colours are randomly chosen. In
    handicap games black receives the handicap stones. -
    A manual method for randomly choosing colours is called
    nigiri. The older player hides a number of white stones
    taken from the bowl, the opponent takes one or two black
    stones to guess the parity, and the parity of the number of
    white stones is revealed. If the opponent guesses right,
    then he takes black, else he takes white.

    5.2 Pass Stones

    Some rules use pass stones. A passing player adds one own
    stone to the prisoners. As a consequence, captures before
    the game end can be resolved in alternation without any loss
    because any not answered approach move is compensated by one
    pass stone. With traditional territory scoring that uses no
    pass stones definition problems arise due to this missing
    option. Modern territory scoring or equivalence scoring use
    pass stones.

    5.3 Equivalence

    Area scoring and territory scoring are close because either
    intersections occupied by own stones or opposing prisoners
    are used. Essentially, every prisoner is a stone removed
    from some intersection. For area it scores one point less
    for the stone's player while for territory it scores one
    point more for his opponent. This is equal. Exact equality
    for the entire game must also consider passes by using pass
    stones and an equal number of moves by requiring white to
    pass last. This is done by equivalence scoring.

    5.4 Meaning of Agreement Removals

    Removals in an agreement phase under area scoring are fair
    because they may as well occur in alternation. Removing a
    stone due to agreement includes its then empty intersection
    and all adjacent empty intersections in the score. Removing
    a stone by means of alternation includes its then empty
    intersection and all adjacent newly occupied intersections
    in the score. -
    With traditional territory scoring this is not possible
    since stones on the board do not score. Thus final captures
    must occur after the game end due to attempted definitions
    in the rules.

    5.5 Practical Scoring Differences

    Since area scoring and modern territory scoring using pass
    stones are equal, correct play is the same for both. Apart
    from Japanese rules exceptions like not scoring empty
    intersections especially in asymmetrical coexistences or
    like a pass-for-ko-rule, traditional territory scoring can
    make a different winner in practically ca. every 10000th
    even game. This is so rare because of a parity feature
    combined with a scarcely odd number of intersections that
    are in coexistences but do not score for area at the game
    end. With area scoring a komi change from 1.5, 3.5, 5.5, ...
    to 2.5, 4.5, 6.5, ... almost always would not change the
    winner. So altough occupying the last empty intersections
    that would otherwise not score just before a game stop gains
    one point each, alternately doing so leaves a total
    advantage of at most one point. Due to the parity feature
    the player to get it is predetermined when this occupation
    starts. More importantly, one final ko is worth 1 point under
    traditional territory scoring but 2 or rarely 4 points under
    area scoring. Rare one-sided points in coexistences provide
    only area. Other practical differences are even rarer. Cute
    players include the stones in their endgame value counts
    during the middle of an area scoring game.

    5.6 Stone Scoring

    In ancient times stone scoring was popular. Only stones on
    the board are scored. Thus empty intersections surrounded by
    own stones are filled until necessary so called eyes remain.
    Disconnected stones require more eyes in total, the so
    called group tax.

    5.7 Old Ing Scoring

    Old Ing rules allowed fractional scores by assigning points
    to neutral empty regions due to the percentage of black and
    white stones surrounding every region.

    5.8 Primitive Rules

    They do not have passes. Alternation ends when a player
    loses due to no legal play. Games can be extremely long and
    include special strategies, so called pass fights. Primitive
    rules (also called no pass rules or Conway rules) can be
    useful in mathematics.

    5.9 Tradition

    Historically, exceptions arose, which some like as such
    especially together with Japanese style rules. So called
    sekis are excluded from the score. Special positions, termed
    precedents, have special rules. Modern Japanese rules have
    generalized a lot of them by a pass-for-ko-rule. After the
    game stop or after the game end and particularly in
    hypothetical play a stone captured in a possible 2-play cycle
    may not be recaptured unless before a pass is made that
    specifies the particular 2-play cycle.

    5.10 Positional / Situational Superko

    Positional superko prohibits a play that recreates a position.
    Situational superko refers to the situation, i.e. to the
    position together with the right to move. So a play is
    prohibited if it recreates a position while the same player
    has the right to move. In practice the differences are
    extremely rare.

    5.11 Handicap Recompensation

    With area scoring handicap stones beyond the first provide
    a potential extra area of one point per handicap stone. Komi
    for white may consider this. Recompensation, H-1 points for H
    handicap stones, is virtually only used together with
    American rules.

    5.12 Mathematics

    Go is a complete information game, i.e. at every move each
    player knows the entire game situation. Hence theoretically
    an algorithm could determine perfect play. However, due to
    the complexity of the game with N intersections, for which
    it is provably impossible to devise a polynomial time
    solution, perfect play or ideal komi are unknown. What one
    does know is that in a game without komi the first player wins
    or ties and that perfect play is independent of set komi. Many
    other propositions have been discovered, some of which
    describe the relation between area and territory scoring, solve
    tiny endgame positions or cyclical behaviour. -
    Go is a very complex game! According to John Tromp, the number
    of legal positions is:

    208168199381979984699478633344862770286522453884530548425 639456820927419612738015378525648451698519643907259916015 628128546089888314427129715319317557736620397247064840935

    For positional superko, no passes, and no resignation, the
    number of possible games is smaller than N**L(N) because L(N)
    also restricts the maximal number of moves per game and there
    are at most N possible intersections per move. (The sign ** is
    a text file notation for "to the power".) -
    Extremely modest estimates look like 10**N, which is based on
    an assumption of 10 reasonable intersections per move. A
    popular estimate for 19x19 go is 10**761, which must have
    originated from a typo and should be 10**361, if at all...
    These types of estimates are so popular because humans cannot
    even imagine the suggested number of atoms in the universe,
    10**80. For comparison, 3**361 is ca. 10**172.

    6 TOURNAMENT RULES

    6.1 Special Game Ends

    If the score considering the komi is zero, then the game is a
    tie and should be treated as 0.5 won games for each. Special
    rules or undue behaviour like sincere lateness might result
    in a referee declaring a win by forfeit, 0:0, or 1:1,
    whichever is most appropriate.

    6.2 Tournament Systems

    A tournament might consist of several stages, of which each
    has a seed and a system. A seed appropriately restricts
    participation, e.g. due to qualification. The most important
    systems are match, league, knockout, Swiss, McMahon. There
    are many others and hybrids. A system must fit the aims of a
    tournament. A sufficient number of rounds, a proper seed,
    and colour variation ensure a fair determination of the best
    player. -
    A match takes place between two players that either play a
    set number of games to see who wins more or a maximal number
    of games to see who wins a predetermined number of games
    first. In a league a small, usually even number of players
    performs a round-robin tournament, so that in each round all
    players play and every two players play against each other,
    one game e.g. A knockout preferably starts with a number of
    players that is a power of two. Losing players are eliminated,
    winning players continue until the winner remains. -
    In a Swiss system before each round each player's achieved
    number of wins is used to pair players with equal numbers as
    far as possible. So all players play all rounds and some time
    the best player will emerge. However, with greatly varying
    strengths too many rounds would be needed. So Swiss is only
    useful for particular events or handicap tournaments.
    McMahon is the refinement of Swiss. Before the start of the
    tournament all players are classified in rank groups, with
    ranks R from 0 to T. This means that one assumes a preceding
    Swiss tournament where every player has already won R games.
    Then in the McMahon tournament the strongest players, who
    deserve the rank T, compete for the top places. In practice,
    one uses a bar B, that is 1 or 2 ranks below T, so that all
    ranks above B are contracted to B and also players slightly
    weaker than the top players get their chance. All players in
    a McMahon play roughly equal opponents; if they win or lose,
    then the opponents will be stronger or weaker.

    6.3 Tie Breakers

    Tie breakers can refine pairings or results. Typically the
    first criterion is the number of wins (or McMahon points);
    all further criteria, if any, are tie breakers. They attempt
    a refinement where a low number of rounds and a tournament
    system do not guarantee sufficient distinction between
    players' achievements. However, they must be applied with
    care since they are only marginally better than coin tossing.
    Examples of tie breakers are direct comparison, which
    acknowledges the winner of a game between two players in
    question, and SOS, which is the Sum of Opponents' Scores. -
    The possible degree of quality of tie breakers is subject to
    discussion. It depends on tournament system, whether only the
    top or all players shall be distinguished, and other factors.
    An alternative to the usage of tie breakers for the final
    results ordering is issuing shared places for all players
    with the same number of wins (or McMahon points). - One must
    fairly assign tie breaker points for opponents missing in
    some round; enforcing participation is preferable especially
    for top players.

    6.4 Pairing

    Pairings must be fair, precise, and consider prior
    achievements during a tournament. One should consider colour
    balance and no pair twice, one might also aim at avoiding a
    pair of players from the same club or country, depending on
    a tournament's intentions. Pairings might be done manually
    in small tournaments; for most tournaments pairing programs
    should be used. These can create fair pairings convincingly,
    some even watch global balance.

    6.5 Thinking Times

    The age of killing each other by greater endurance has gone.
    Clocks are used to count each player's remaining thinking
    time. Typically, every game has a basic time and overtime
    periods. Exceeding a time limit loses a game. Basic time
    might be 9 hours for a professional top game, 10 minutes for
    a lightning game, or something in between that fits a
    tournament's intentions. An overtime period requires a fixed
    number of moves within a predetermined period, e.g. 1 move
    within 60 seconds. A move is finished by pressing the clock.
    - Many variants or other time systems exist, e.g., increasing
    numbers of moves in further overtime periods, penalty points
    for entering further periods, full usage of every overtime
    period, thinking time working like an hour glass, etc.

    6.6 Tournament Rules

    Every tournament uses an announced set of tournament rules.
    They especially specify the used set for the core rules of
    play, the tournament system, tie breakers, the pairing
    method, the winning criteria, compensation methods,
    thinking times, direction, jurisdiction, adjournment
    methods, penalities for being late, etc. Tournament rules
    often deal with details. Not everything can be predicted, so
    a sportsmanlike spirit is mentioned. Finally, it should be
    clear which of several rule sets takes precedence.

    6.7 Tournament Organization

    A regional tournament can be organized by a club. Big events
    can be held at the request of an association or federation,
    who also supervise. A tournament organization is responsible
    for providing a venue and playing material. It must be
    distinguished from the tournament director and his assistant
    directors, who perform the particular tasks of pairing,
    collecting results, and ensuring smooth running. Shared
    power furthermore demands independent referees.

    6.8 Jurisdiction

    Before the start of a tournament valid instances of a
    jurisdiction as well as the persons to be referees must be
    clear. Typically, for a tournament itself there is one
    referee as the first instance and a body of three referees
    as the second instance. For very peculiar cases a federation
    could have a third and final instance. Some tournament rules
    replace the second instance by a single person, called chief
    referee; to avoid confusion he ought not to judge as the
    first instance. Players should respect the referees' tough
    job of mediation or decision; referees should seriously
    enforce the rules.

    6.9 Prizes

    The first places of a tournament invoke major prizes. E.g.
    the first, second, third places might get 3/6, 2/6, 1/6 of
    the available money. In a tournament with many weaker
    players it is a good idea to provide some prizes for all
    other players that win most rounds as well. While prizes can
    be money, books, trophies, etc., one should remember that
    money is most universally accepted and trophies serve the
    media better than the winners. -
    On a related topic, a side event lottery must give equal
    chances to all participants. This is only achieved by using
    one lot for each.

    7 Links

    Most rules information, links, short rules: http://home.snafu.de/jasiek/rules.html

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Robert Jasiek@21:1/5 to All on Fri Oct 12 13:34:21 2018
    Title: Rules FAQ
    Author: Robert Jasiek <jasiek@snafu.de>
    Frequency: monthly
    Last Update: 2017-10-13; First Day: 1999-04-12
    Distribution: rec.games.go
    Copyright: free non-commercial usage for promotion

    0 CONTENTS

    1 Purpose of this Paper
    2 Information for Beginners
    3 Important Concepts
    4 Particular Rules
    5 Troublesome Details
    6 Tournament Rules
    7 Links

    1 PURPOSE OF THIS PAPER

    This paper is a basic reference for important rules terms,
    rules, and tournament rules. Beginners should read
    especially Chapters 2 and 3, players Chapters 3 to 5,
    tournament players and organizers Chapter 6.

    2 INFORMATION FOR BEGINNERS
    2.1 What Must I Know as a Beginner?

    The game is played on a grid board. Typically it has 19x19
    intersections, but 9x9 are also fine. Two players compete.
    The first player uses black stones, the other white.

    The players alternate. A player may play or pass. Playing
    is putting one's own stone on an empty intersection and
    removing any surrounded opposing stones. To avoid
    cycles, a play may not recreate any prior configuration of
    all stones on the board.

    Two successive passes end the game. Then the player with
    more intersections wins. Intersections are his if only his
    stones occupy or surround them.

    2.2 Which Rules do I Need as a Beginner?

    You can play with short rules as in 2.1. Other rules may
    be different, but the game is the same, i. e. strategy,
    tactics, and the score do not change. Extremely rare
    exceptions confirm this rule.

    The winner can be determined by area or by territory.
    Either includes empty intersections surrounded only by own
    stones. While area adds intersections occupied by own
    stones, territory adds opposing prisoners instead.

    All rules, except short rules, have further phases after
    alternation and before scoring. Towards a game end it is
    often clear which stones will be removed. The additional
    phases allow the players to agree on which stones shall be
    removed. Thereby final removals do not require alternation.

    Whether you score by area or by territory or whether you
    remove by alternation or by agreement should mainly depend
    on which rules are used by people you play with.

    2.3 Which Rules Should I Teach?

    One possibility is to use a board with 9x9 intersections,
    short rules as in 2.1, and count each player's score by
    using a finger to scan the board for his intersections.

    3 IMPORTANT CONCEPTS

    While strategy and tactics virtually remain the same,
    concepts vary in different rules. However, the following
    gives a comprehensive overview on standard terms.

    3.1 Stone, String

    The physical device that colours one intersection in a
    play is a STONE. Two intersections of the board are
    ADJACENT if they have a line but no intersection between
    them. Two intersections with either black, white, or no
    stones on them are CONNECTED if they are adjacent or if
    there is a chain of adjacent intersections of their type
    between them. A REGION consists of an intersection and
    any intersections connected to it. A black or white
    region is called a STRING.

    3.2 Surrounded

    An intersection of one colour is SURROUNDED by another
    colour if each leaving path reaches the other colour first
    after the one colour. Hereby it can only be surrounded
    black by white, white by black, empty by black, or empty
    by white. A region can be surrounded. For strings there is
    an alternative notion of no liberty (or breath). A LIBERTY
    of a string is an empty intersection adjacent to it. Thus
    a string is surrounded if and only if it has no liberty.

    3.3 Removal, Suicide

    A removal empties the intersections of surrounded stones
    if there are any. Hereby removal of opposing stones is
    executed first, if necessary. Rules may either require or
    forbid removal of own stones. This is called suicide or no
    suicide. In practice, suicide might be used for so called ko
    fights or in capturing races.

    3.4 Capture, Prisoner

    Rules that score territory call a removal a capture
    because all removed stones are seriously kept as prisoners.

    3.5 Move, Play, Pass

    The players have alternate turns. On each turn a player makes
    a move that is either a play or a pass. A play places one's
    own stone on an empty intersection. It can then include
    removal of surrounded stones, if any. A pass merely continues
    alternation by giving the opponent the next turn.

    3.6 Compensation

    The first move advantage by black can be compensated by
    compensation points (komi) that are added to the white score
    after the game end. Komi can be adjusted by 0.5 to avoid
    ties. Today integer values for komi for 19x19 boards
    typically range between 5 and 7. For 13x13 boards one should
    use 8, for 9x9 boards 6; however, there is no real consensus
    for small board komi values yet. -
    A weaker player (black) can get the right to place an agreed
    number of compensation stones (handicap) before white's first
    play. Rules may allow free or fixed handicap. Free handicap
    does not apply any restriction. Fixed handicap requires
    traditional placement on set intersections.

    3.7 Phases

    Normally, a game consists of the phases alternation,
    agreement, scoring. A game stop is between alternation and
    agreement, the game end is between agreement and scoring,
    and after scoring both players accept the counted score as
    the result. The main part of the game is the alternation
    phase. Special rules are invoked after it. Typically, two
    successive passes in alternation are the game stop and start
    the agreement phase. In it the players may agree on strings
    to be removed. If they agree, then they remove those strings
    from the board; this ends the game. Sometimes they might
    disagree, then no strings are removed but alternation is
    resumed as if the last game stop did not occur.

    3.8 Recreation

    The position is the pattern of black and white stones on the
    board. Without extra rule a position might be repeated
    infinitely. The easiest rule to prohibit this says: A play
    may not recreate a position. This refers to positions after
    completion of plays, i.e. after possible removals. The rule
    is called "superko". -
    Some rules use concepts different from superko. They combine
    a "2-play rule" with a "long cycle rule". The first says:
    Two successive plays may not recreate a position. The second
    says: If a position is recreated after more than two moves,
    then the game ends either immediately or, as a variant, as
    soon as the players agree, with the result "without result".
    In practice the 2-play rule is sufficient for almost all
    cases. It handles the relevant standard pattern of two
    adjacent intersections. For superko this is just a special
    application.

    3.9 Scoring

    The score is the result after the game end as defined by
    the rules. There are two different scoring methods: area
    scoring and territory scoring. Rules use one of them. Both
    give the same result in almost all cases and both evaluate
    the difference of the black and the white scores. A player's
    AREA score is the sum of intersections with own stones and
    of empty intersections surrounded only by own stones. Simply
    speaking, a player's TERRITORY score is the sum of empty
    intersections surrounded only by own stones and of prisoners
    of opposing colour. With both scoring methods empty
    intersections that are not surrounded by either black or
    white are neutral.

    3.10 Counting

    A score must be determined by some mechanical procedure in
    practice; this is called counting. There are various methods.
    Some rules prescribe one. A possible method is to use one's
    finger to count point by point. Other methods rearrange a lot
    of stones on the board.

    4 PARTICULAR RULES

    Rules vary extremely. However, in practice they often give
    the same result.

    4.1 Short Rules

    Examples of short rules are the Simple Rules or the
    Tromp-Taylor rules. They have no game stop and no agreement.
    Both are superfluous since necessary removals may already be
    performed in the alternation. Two successive passes end the
    game that is scored then. Short rules use area scoring,
    superko, and suicide. Further settings are left for
    tournament rules.

    4.2 American Rules

    These are used by the American Go Association. They use
    situational superko, no suicide, and 7.5 komi. They permit
    free or fixed handicap. Their most remarkable feature is to
    allow one of area scoring or territory scoring. Herefore
    pass stones (one prisoner compensates each pass) and white
    moving last always ensure the same result, regardless of the
    applied scoring method.

    4.3 Chinese Rules

    These are used in continental China and sometimes in other
    countries. Area scoring and no suicide are used.

    4.3.1 Official Chinese Rules

    In practice, ko rules roughly amount to a 2-play rule and a
    long cycle rule. The mentioned superko is overridden. The
    counting is a sophisticated half counting, where empty
    intersections and then after rearrangements stones of one
    colour are added to be compared with half the non-neutral
    intersections. The komi as a half komi is 3.75. In full
    counting, counts and komi would be twice as big.

    4.3.2 Simplified Chinese Rules

    Positional superko is used. A counting method is not
    prescribed. The full komi should be 7.5.

    4.4 Japanese Rules

    The differences mainly affect handling of late game phases
    but often do not alter scores. Japanese rules use some
    traditional territory scoring that attempts to exclude so
    called sekis. No suicide applies. The core of the ko rules
    is a 2-play rule and a long cycle rule. Typically, komi is
    6.5. Fixed handicap should be used. The counting is a
    sophisticated rearrangement of empty intersections and
    filling-in of prisoners.

    4.4.1 Game Finishing Process

    A game finishes with the following process: 1) So called
    dame (neutral points) and defensive moves (necessary
    connections etc. due to occupied dame) are filled.
    2) The hypothetical analysis, which presumes perfect play,
    determines so called life or death of each string and the
    scoring intersections. 3) Without making any approach moves,
    dead stones are removed from scoring intersections and added
    to the prisoners. 4) The score is counted. (2) and (3) do not
    allow to play out life and death since actually filling
    intersections costs points in Japanese rules.

    4.4.2 Official Japanese Rules

    There are the Japanese 1989 Rules, which are used in Japan
    and elsewhere, and the World Amateur Go Championships Rules,
    which are used in some particular tournaments. Korean rules
    are similar to Japanese rules but have a very different text
    and differ in rare positions. Official Japanese rules are
    very incomplete and have messy late game phases. E.g., the
    Japanese 1989 Rules allow filling of dame during alternation,
    after it, or both and have a so called ko-pass-rule for the
    hypothetical analysis. Now professional Japanese rules are
    explained precisely by a rules expert's interpretation called
    "the Japanese 2003 Rules".

    4.4.3 Simplified Japanese Rules

    As a recent invention, they are not used yet. They are
    complete and have clear late game phases. Filling of dame is
    done during alternation.

    4.4.4 Verbal Japanese Rules

    They are used for informal games in many countries and
    undefined, except that the game finishing process is used.
    In a tournament without any official rules of play, disputes
    are not solved due to the rules but with a referee.

    4.5 Ing Rules

    Ing rules use area scoring, suicide, 8 komi with black
    winning ties, and free handicap.

    4.5.1 Official Ing Rules

    The ko rules are a mess but somehow resemble superko.
    Details could fill books. The late game phases are specified
    insufficiently. The peculiar counting method requires 180
    stones of each colour throughout the game, fills any stones
    on the board after the game end, and leaves exactly one
    empty intersection, which determines the winner. The
    official rules are used in professional Taiwanese and some
    sponsored tournaments. Taiwanese amateurs have their own
    rules.

    4.5.2 Simplified Ing Rules

    Positional superko is used. A counting method is not
    prescribed. The late game phases are specified clearly. The
    simplified rules are used in EGF tournaments that are said
    to use Ing rules.

    4.6 New Zealand Rules

    Area scoring, suicide, situational superko, 7 komi, and free
    handicap are used.

    4.7 Go Server Rules

    Every go server has its own and often complicated rules, if
    any, so they cannot be given in detail here. Concerning
    "IGS rules", territory scoring, no suicide, a 2-play rule,
    fixed handicap, three game stopping passes, and captures in
    an agreement phase are used. Details about agreements and
    long cycles are not specified and lead to adjourned games in
    case of doubt. Komi is suggested but may be altered. Counting
    is automatic. "Yahoo" has territory scoring, no suicide, a
    2-play rule, two game stopping passes; long cycles and
    disagreements are not handled properly. On "email servers"
    players must agree on any rules. -
    Typically territory scoring on a go server means that neither
    points in any sekis are excluded nor pass stones are used.
    Thus while the Japanese seki exception is abandoned,
    disagreements about removals may lead to games without result
    since playing out can cost points.

    4.8 International Rules

    The international mailing list go-rules has proposed
    international rules, however, none are adopted yet. The core
    rules of play shall be clear, complete, and correct.
    Currently alternative texts are offered for suicide,
    recreation, and scoring. Especially unification of scoring
    methods is advocated.

    4.9 EGF Rules

    The EGF uses the Simplified Ing Rules with 8 komi (black
    wins ties) in Ing sponsored tournaments and the Nihon Kiin
    1989 Rules with 6.5 komi in Japanese/Korean sponsored
    tournaments. If significantly the European Go Championship
    has both kinds of sponsors, then boards 1-16 use the Nihon
    Kiin 1989 Rules and boards 17+ the Simplified Ing Rules.
    However, time settings depend on ranks.

    5 TROUBLESOME DETAILS

    5.1 Colour Choice

    In even games typically the colours are randomly chosen. In
    handicap games black receives the handicap stones. -
    A manual method for randomly choosing colours is called
    nigiri. The older player hides a number of white stones
    taken from the bowl, the opponent takes one or two black
    stones to guess the parity, and the parity of the number of
    white stones is revealed. If the opponent guesses right,
    then he takes black, else he takes white.

    5.2 Pass Stones

    Some rules use pass stones. A passing player adds one own
    stone to the prisoners. As a consequence, captures before
    the game end can be resolved in alternation without any loss
    because any not answered approach move is compensated by one
    pass stone. With traditional territory scoring that uses no
    pass stones definition problems arise due to this missing
    option. Modern territory scoring or equivalence scoring use
    pass stones.

    5.3 Equivalence

    Area scoring and territory scoring are close because either
    intersections occupied by own stones or opposing prisoners
    are used. Essentially, every prisoner is a stone removed
    from some intersection. For area it scores one point less
    for the stone's player while for territory it scores one
    point more for his opponent. This is equal. Exact equality
    for the entire game must also consider passes by using pass
    stones and an equal number of moves by requiring white to
    pass last. This is done by equivalence scoring.

    5.4 Meaning of Agreement Removals

    Removals in an agreement phase under area scoring are fair
    because they may as well occur in alternation. Removing a
    stone due to agreement includes its then empty intersection
    and all adjacent empty intersections in the score. Removing
    a stone by means of alternation includes its then empty
    intersection and all adjacent newly occupied intersections
    in the score. -
    With traditional territory scoring this is not possible
    since stones on the board do not score. Thus final captures
    must occur after the game end due to attempted definitions
    in the rules.

    5.5 Practical Scoring Differences

    Since area scoring and modern territory scoring using pass
    stones are equal, correct play is the same for both. Apart
    from Japanese rules exceptions like not scoring empty
    intersections especially in asymmetrical coexistences or
    like a pass-for-ko-rule, traditional territory scoring can
    make a different winner in practically ca. every 10000th
    even game. This is so rare because of a parity feature
    combined with a scarcely odd number of intersections that
    are in coexistences but do not score for area at the game
    end. With area scoring a komi change from 1.5, 3.5, 5.5, ...
    to 2.5, 4.5, 6.5, ... almost always would not change the
    winner. So altough occupying the last empty intersections
    that would otherwise not score just before a game stop gains
    one point each, alternately doing so leaves a total
    advantage of at most one point. Due to the parity feature
    the player to get it is predetermined when this occupation
    starts. More importantly, one final ko is worth 1 point under
    traditional territory scoring but 2 or rarely 4 points under
    area scoring. Rare one-sided points in coexistences provide
    only area. Other practical differences are even rarer. Cute
    players include the stones in their endgame value counts
    during the middle of an area scoring game.

    5.6 Stone Scoring

    In ancient times stone scoring was popular. Only stones on
    the board are scored. Thus empty intersections surrounded by
    own stones are filled until necessary so called eyes remain.
    Disconnected stones require more eyes in total, the so
    called group tax.

    5.7 Old Ing Scoring

    Old Ing rules allowed fractional scores by assigning points
    to neutral empty regions due to the percentage of black and
    white stones surrounding every region.

    5.8 Primitive Rules

    They do not have passes. Alternation ends when a player
    loses due to no legal play. Games can be extremely long and
    include special strategies, so called pass fights. Primitive
    rules (also called no pass rules or Conway rules) can be
    useful in mathematics.

    5.9 Tradition

    Historically, exceptions arose, which some like as such
    especially together with Japanese style rules. So called
    sekis are excluded from the score. Special positions, termed
    precedents, have special rules. Modern Japanese rules have
    generalized a lot of them by a pass-for-ko-rule. After the
    game stop or after the game end and particularly in
    hypothetical play a stone captured in a possible 2-play cycle
    may not be recaptured unless before a pass is made that
    specifies the particular 2-play cycle.

    5.10 Positional / Situational Superko

    Positional superko prohibits a play that recreates a position.
    Situational superko refers to the situation, i.e. to the
    position together with the right to move. So a play is
    prohibited if it recreates a position while the same player
    has the right to move. In practice the differences are
    extremely rare.

    5.11 Handicap Recompensation

    With area scoring handicap stones beyond the first provide
    a potential extra area of one point per handicap stone. Komi
    for white may consider this. Recompensation, H-1 points for H
    handicap stones, is virtually only used together with
    American rules.

    5.12 Mathematics

    Go is a complete information game, i.e. at every move each
    player knows the entire game situation. Hence theoretically
    an algorithm could determine perfect play. However, due to
    the complexity of the game with N intersections, for which
    it is provably impossible to devise a polynomial time
    solution, perfect play or ideal komi are unknown. What one
    does know is that in a game without komi the first player wins
    or ties and that perfect play is independent of set komi. Many
    other propositions have been discovered, some of which
    describe the relation between area and territory scoring, solve
    tiny endgame positions or cyclical behaviour. -
    Go is a very complex game! According to John Tromp, the number
    of legal positions is:

    208168199381979984699478633344862770286522453884530548425 639456820927419612738015378525648451698519643907259916015 628128546089888314427129715319317557736620397247064840935

    For positional superko, no passes, and no resignation, the
    number of possible games is smaller than N**L(N) because L(N)
    also restricts the maximal number of moves per game and there
    are at most N possible intersections per move. (The sign ** is
    a text file notation for "to the power".) -
    Extremely modest estimates look like 10**N, which is based on
    an assumption of 10 reasonable intersections per move. A
    popular estimate for 19x19 go is 10**761, which must have
    originated from a typo and should be 10**361, if at all...
    These types of estimates are so popular because humans cannot
    even imagine the suggested number of atoms in the universe,
    10**80. For comparison, 3**361 is ca. 10**172.

    6 TOURNAMENT RULES

    6.1 Special Game Ends

    If the score considering the komi is zero, then the game is a
    tie and should be treated as 0.5 won games for each. Special
    rules or undue behaviour like sincere lateness might result
    in a referee declaring a win by forfeit, 0:0, or 1:1,
    whichever is most appropriate.

    6.2 Tournament Systems

    A tournament might consist of several stages, of which each
    has a seed and a system. A seed appropriately restricts
    participation, e.g. due to qualification. The most important
    systems are match, league, knockout, Swiss, McMahon. There
    are many others and hybrids. A system must fit the aims of a
    tournament. A sufficient number of rounds, a proper seed,
    and colour variation ensure a fair determination of the best
    player. -
    A match takes place between two players that either play a
    set number of games to see who wins more or a maximal number
    of games to see who wins a predetermined number of games
    first. In a league a small, usually even number of players
    performs a round-robin tournament, so that in each round all
    players play and every two players play against each other,
    one game e.g. A knockout preferably starts with a number of
    players that is a power of two. Losing players are eliminated,
    winning players continue until the winner remains. -
    In a Swiss system before each round each player's achieved
    number of wins is used to pair players with equal numbers as
    far as possible. So all players play all rounds and some time
    the best player will emerge. However, with greatly varying
    strengths too many rounds would be needed. So Swiss is only
    useful for particular events or handicap tournaments.
    McMahon is the refinement of Swiss. Before the start of the
    tournament all players are classified in rank groups, with
    ranks R from 0 to T. This means that one assumes a preceding
    Swiss tournament where every player has already won R games.
    Then in the McMahon tournament the strongest players, who
    deserve the rank T, compete for the top places. In practice,
    one uses a bar B, that is 1 or 2 ranks below T, so that all
    ranks above B are contracted to B and also players slightly
    weaker than the top players get their chance. All players in
    a McMahon play roughly equal opponents; if they win or lose,
    then the opponents will be stronger or weaker.

    6.3 Tie Breakers

    Tie breakers can refine pairings or results. Typically the
    first criterion is the number of wins (or McMahon points);
    all further criteria, if any, are tie breakers. They attempt
    a refinement where a low number of rounds and a tournament
    system do not guarantee sufficient distinction between
    players' achievements. However, they must be applied with
    care since they are only marginally better than coin tossing.
    Examples of tie breakers are direct comparison, which
    acknowledges the winner of a game between two players in
    question, and SOS, which is the Sum of Opponents' Scores. -
    The possible degree of quality of tie breakers is subject to
    discussion. It depends on tournament system, whether only the
    top or all players shall be distinguished, and other factors.
    An alternative to the usage of tie breakers for the final
    results ordering is issuing shared places for all players
    with the same number of wins (or McMahon points). - One must
    fairly assign tie breaker points for opponents missing in
    some round; enforcing participation is preferable especially
    for top players.

    6.4 Pairing

    Pairings must be fair, precise, and consider prior
    achievements during a tournament. One should consider colour
    balance and no pair twice, one might also aim at avoiding a
    pair of players from the same club or country, depending on
    a tournament's intentions. Pairings might be done manually
    in small tournaments; for most tournaments pairing programs
    should be used. These can create fair pairings convincingly,
    some even watch global balance.

    6.5 Thinking Times

    The age of killing each other by greater endurance has gone.
    Clocks are used to count each player's remaining thinking
    time. Typically, every game has a basic time and overtime
    periods. Exceeding a time limit loses a game. Basic time
    might be 9 hours for a professional top game, 10 minutes for
    a lightning game, or something in between that fits a
    tournament's intentions. An overtime period requires a fixed
    number of moves within a predetermined period, e.g. 1 move
    within 60 seconds. A move is finished by pressing the clock.
    - Many variants or other time systems exist, e.g., increasing
    numbers of moves in further overtime periods, penalty points
    for entering further periods, full usage of every overtime
    period, thinking time working like an hour glass, etc.

    6.6 Tournament Rules

    Every tournament uses an announced set of tournament rules.
    They especially specify the used set for the core rules of
    play, the tournament system, tie breakers, the pairing
    method, the winning criteria, compensation methods,
    thinking times, direction, jurisdiction, adjournment
    methods, penalities for being late, etc. Tournament rules
    often deal with details. Not everything can be predicted, so
    a sportsmanlike spirit is mentioned. Finally, it should be
    clear which of several rule sets takes precedence.

    6.7 Tournament Organization

    A regional tournament can be organized by a club. Big events
    can be held at the request of an association or federation,
    who also supervise. A tournament organization is responsible
    for providing a venue and playing material. It must be
    distinguished from the tournament director and his assistant
    directors, who perform the particular tasks of pairing,
    collecting results, and ensuring smooth running. Shared
    power furthermore demands independent referees.

    6.8 Jurisdiction

    Before the start of a tournament valid instances of a
    jurisdiction as well as the persons to be referees must be
    clear. Typically, for a tournament itself there is one
    referee as the first instance and a body of three referees
    as the second instance. For very peculiar cases a federation
    could have a third and final instance. Some tournament rules
    replace the second instance by a single person, called chief
    referee; to avoid confusion he ought not to judge as the
    first instance. Players should respect the referees' tough
    job of mediation or decision; referees should seriously
    enforce the rules.

    6.9 Prizes

    The first places of a tournament invoke major prizes. E.g.
    the first, second, third places might get 3/6, 2/6, 1/6 of
    the available money. In a tournament with many weaker
    players it is a good idea to provide some prizes for all
    other players that win most rounds as well. While prizes can
    be money, books, trophies, etc., one should remember that
    money is most universally accepted and trophies serve the
    media better than the winners. -
    On a related topic, a side event lottery must give equal
    chances to all participants. This is only achieved by using
    one lot for each.

    7 Links

    Most rules information, links, short rules: http://home.snafu.de/jasiek/rules.html

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Robert Jasiek@21:1/5 to All on Wed Dec 12 06:44:49 2018
    Title: Rules FAQ
    Author: Robert Jasiek <jasiek@snafu.de>
    Frequency: monthly
    Last Update: 2017-10-13; First Day: 1999-04-12
    Distribution: rec.games.go
    Copyright: free non-commercial usage for promotion

    0 CONTENTS

    1 Purpose of this Paper
    2 Information for Beginners
    3 Important Concepts
    4 Particular Rules
    5 Troublesome Details
    6 Tournament Rules
    7 Links

    1 PURPOSE OF THIS PAPER

    This paper is a basic reference for important rules terms,
    rules, and tournament rules. Beginners should read
    especially Chapters 2 and 3, players Chapters 3 to 5,
    tournament players and organizers Chapter 6.

    2 INFORMATION FOR BEGINNERS
    2.1 What Must I Know as a Beginner?

    The game is played on a grid board. Typically it has 19x19
    intersections, but 9x9 are also fine. Two players compete.
    The first player uses black stones, the other white.

    The players alternate. A player may play or pass. Playing
    is putting one's own stone on an empty intersection and
    removing any surrounded opposing stones. To avoid
    cycles, a play may not recreate any prior configuration of
    all stones on the board.

    Two successive passes end the game. Then the player with
    more intersections wins. Intersections are his if only his
    stones occupy or surround them.

    2.2 Which Rules do I Need as a Beginner?

    You can play with short rules as in 2.1. Other rules may
    be different, but the game is the same, i. e. strategy,
    tactics, and the score do not change. Extremely rare
    exceptions confirm this rule.

    The winner can be determined by area or by territory.
    Either includes empty intersections surrounded only by own
    stones. While area adds intersections occupied by own
    stones, territory adds opposing prisoners instead.

    All rules, except short rules, have further phases after
    alternation and before scoring. Towards a game end it is
    often clear which stones will be removed. The additional
    phases allow the players to agree on which stones shall be
    removed. Thereby final removals do not require alternation.

    Whether you score by area or by territory or whether you
    remove by alternation or by agreement should mainly depend
    on which rules are used by people you play with.

    2.3 Which Rules Should I Teach?

    One possibility is to use a board with 9x9 intersections,
    short rules as in 2.1, and count each player's score by
    using a finger to scan the board for his intersections.

    3 IMPORTANT CONCEPTS

    While strategy and tactics virtually remain the same,
    concepts vary in different rules. However, the following
    gives a comprehensive overview on standard terms.

    3.1 Stone, String

    The physical device that colours one intersection in a
    play is a STONE. Two intersections of the board are
    ADJACENT if they have a line but no intersection between
    them. Two intersections with either black, white, or no
    stones on them are CONNECTED if they are adjacent or if
    there is a chain of adjacent intersections of their type
    between them. A REGION consists of an intersection and
    any intersections connected to it. A black or white
    region is called a STRING.

    3.2 Surrounded

    An intersection of one colour is SURROUNDED by another
    colour if each leaving path reaches the other colour first
    after the one colour. Hereby it can only be surrounded
    black by white, white by black, empty by black, or empty
    by white. A region can be surrounded. For strings there is
    an alternative notion of no liberty (or breath). A LIBERTY
    of a string is an empty intersection adjacent to it. Thus
    a string is surrounded if and only if it has no liberty.

    3.3 Removal, Suicide

    A removal empties the intersections of surrounded stones
    if there are any. Hereby removal of opposing stones is
    executed first, if necessary. Rules may either require or
    forbid removal of own stones. This is called suicide or no
    suicide. In practice, suicide might be used for so called ko
    fights or in capturing races.

    3.4 Capture, Prisoner

    Rules that score territory call a removal a capture
    because all removed stones are seriously kept as prisoners.

    3.5 Move, Play, Pass

    The players have alternate turns. On each turn a player makes
    a move that is either a play or a pass. A play places one's
    own stone on an empty intersection. It can then include
    removal of surrounded stones, if any. A pass merely continues
    alternation by giving the opponent the next turn.

    3.6 Compensation

    The first move advantage by black can be compensated by
    compensation points (komi) that are added to the white score
    after the game end. Komi can be adjusted by 0.5 to avoid
    ties. Today integer values for komi for 19x19 boards
    typically range between 5 and 7. For 13x13 boards one should
    use 8, for 9x9 boards 6; however, there is no real consensus
    for small board komi values yet. -
    A weaker player (black) can get the right to place an agreed
    number of compensation stones (handicap) before white's first
    play. Rules may allow free or fixed handicap. Free handicap
    does not apply any restriction. Fixed handicap requires
    traditional placement on set intersections.

    3.7 Phases

    Normally, a game consists of the phases alternation,
    agreement, scoring. A game stop is between alternation and
    agreement, the game end is between agreement and scoring,
    and after scoring both players accept the counted score as
    the result. The main part of the game is the alternation
    phase. Special rules are invoked after it. Typically, two
    successive passes in alternation are the game stop and start
    the agreement phase. In it the players may agree on strings
    to be removed. If they agree, then they remove those strings
    from the board; this ends the game. Sometimes they might
    disagree, then no strings are removed but alternation is
    resumed as if the last game stop did not occur.

    3.8 Recreation

    The position is the pattern of black and white stones on the
    board. Without extra rule a position might be repeated
    infinitely. The easiest rule to prohibit this says: A play
    may not recreate a position. This refers to positions after
    completion of plays, i.e. after possible removals. The rule
    is called "superko". -
    Some rules use concepts different from superko. They combine
    a "2-play rule" with a "long cycle rule". The first says:
    Two successive plays may not recreate a position. The second
    says: If a position is recreated after more than two moves,
    then the game ends either immediately or, as a variant, as
    soon as the players agree, with the result "without result".
    In practice the 2-play rule is sufficient for almost all
    cases. It handles the relevant standard pattern of two
    adjacent intersections. For superko this is just a special
    application.

    3.9 Scoring

    The score is the result after the game end as defined by
    the rules. There are two different scoring methods: area
    scoring and territory scoring. Rules use one of them. Both
    give the same result in almost all cases and both evaluate
    the difference of the black and the white scores. A player's
    AREA score is the sum of intersections with own stones and
    of empty intersections surrounded only by own stones. Simply
    speaking, a player's TERRITORY score is the sum of empty
    intersections surrounded only by own stones and of prisoners
    of opposing colour. With both scoring methods empty
    intersections that are not surrounded by either black or
    white are neutral.

    3.10 Counting

    A score must be determined by some mechanical procedure in
    practice; this is called counting. There are various methods.
    Some rules prescribe one. A possible method is to use one's
    finger to count point by point. Other methods rearrange a lot
    of stones on the board.

    4 PARTICULAR RULES

    Rules vary extremely. However, in practice they often give
    the same result.

    4.1 Short Rules

    Examples of short rules are the Simple Rules or the
    Tromp-Taylor rules. They have no game stop and no agreement.
    Both are superfluous since necessary removals may already be
    performed in the alternation. Two successive passes end the
    game that is scored then. Short rules use area scoring,
    superko, and suicide. Further settings are left for
    tournament rules.

    4.2 American Rules

    These are used by the American Go Association. They use
    situational superko, no suicide, and 7.5 komi. They permit
    free or fixed handicap. Their most remarkable feature is to
    allow one of area scoring or territory scoring. Herefore
    pass stones (one prisoner compensates each pass) and white
    moving last always ensure the same result, regardless of the
    applied scoring method.

    4.3 Chinese Rules

    These are used in continental China and sometimes in other
    countries. Area scoring and no suicide are used.

    4.3.1 Official Chinese Rules

    In practice, ko rules roughly amount to a 2-play rule and a
    long cycle rule. The mentioned superko is overridden. The
    counting is a sophisticated half counting, where empty
    intersections and then after rearrangements stones of one
    colour are added to be compared with half the non-neutral
    intersections. The komi as a half komi is 3.75. In full
    counting, counts and komi would be twice as big.

    4.3.2 Simplified Chinese Rules

    Positional superko is used. A counting method is not
    prescribed. The full komi should be 7.5.

    4.4 Japanese Rules

    The differences mainly affect handling of late game phases
    but often do not alter scores. Japanese rules use some
    traditional territory scoring that attempts to exclude so
    called sekis. No suicide applies. The core of the ko rules
    is a 2-play rule and a long cycle rule. Typically, komi is
    6.5. Fixed handicap should be used. The counting is a
    sophisticated rearrangement of empty intersections and
    filling-in of prisoners.

    4.4.1 Game Finishing Process

    A game finishes with the following process: 1) So called
    dame (neutral points) and defensive moves (necessary
    connections etc. due to occupied dame) are filled.
    2) The hypothetical analysis, which presumes perfect play,
    determines so called life or death of each string and the
    scoring intersections. 3) Without making any approach moves,
    dead stones are removed from scoring intersections and added
    to the prisoners. 4) The score is counted. (2) and (3) do not
    allow to play out life and death since actually filling
    intersections costs points in Japanese rules.

    4.4.2 Official Japanese Rules

    There are the Japanese 1989 Rules, which are used in Japan
    and elsewhere, and the World Amateur Go Championships Rules,
    which are used in some particular tournaments. Korean rules
    are similar to Japanese rules but have a very different text
    and differ in rare positions. Official Japanese rules are
    very incomplete and have messy late game phases. E.g., the
    Japanese 1989 Rules allow filling of dame during alternation,
    after it, or both and have a so called ko-pass-rule for the
    hypothetical analysis. Now professional Japanese rules are
    explained precisely by a rules expert's interpretation called
    "the Japanese 2003 Rules".

    4.4.3 Simplified Japanese Rules

    As a recent invention, they are not used yet. They are
    complete and have clear late game phases. Filling of dame is
    done during alternation.

    4.4.4 Verbal Japanese Rules

    They are used for informal games in many countries and
    undefined, except that the game finishing process is used.
    In a tournament without any official rules of play, disputes
    are not solved due to the rules but with a referee.

    4.5 Ing Rules

    Ing rules use area scoring, suicide, 8 komi with black
    winning ties, and free handicap.

    4.5.1 Official Ing Rules

    The ko rules are a mess but somehow resemble superko.
    Details could fill books. The late game phases are specified
    insufficiently. The peculiar counting method requires 180
    stones of each colour throughout the game, fills any stones
    on the board after the game end, and leaves exactly one
    empty intersection, which determines the winner. The
    official rules are used in professional Taiwanese and some
    sponsored tournaments. Taiwanese amateurs have their own
    rules.

    4.5.2 Simplified Ing Rules

    Positional superko is used. A counting method is not
    prescribed. The late game phases are specified clearly. The
    simplified rules are used in EGF tournaments that are said
    to use Ing rules.

    4.6 New Zealand Rules

    Area scoring, suicide, situational superko, 7 komi, and free
    handicap are used.

    4.7 Go Server Rules

    Every go server has its own and often complicated rules, if
    any, so they cannot be given in detail here. Concerning
    "IGS rules", territory scoring, no suicide, a 2-play rule,
    fixed handicap, three game stopping passes, and captures in
    an agreement phase are used. Details about agreements and
    long cycles are not specified and lead to adjourned games in
    case of doubt. Komi is suggested but may be altered. Counting
    is automatic. "Yahoo" has territory scoring, no suicide, a
    2-play rule, two game stopping passes; long cycles and
    disagreements are not handled properly. On "email servers"
    players must agree on any rules. -
    Typically territory scoring on a go server means that neither
    points in any sekis are excluded nor pass stones are used.
    Thus while the Japanese seki exception is abandoned,
    disagreements about removals may lead to games without result
    since playing out can cost points.

    4.8 International Rules

    The international mailing list go-rules has proposed
    international rules, however, none are adopted yet. The core
    rules of play shall be clear, complete, and correct.
    Currently alternative texts are offered for suicide,
    recreation, and scoring. Especially unification of scoring
    methods is advocated.

    4.9 EGF Rules

    The EGF uses the Simplified Ing Rules with 8 komi (black
    wins ties) in Ing sponsored tournaments and the Nihon Kiin
    1989 Rules with 6.5 komi in Japanese/Korean sponsored
    tournaments. If significantly the European Go Championship
    has both kinds of sponsors, then boards 1-16 use the Nihon
    Kiin 1989 Rules and boards 17+ the Simplified Ing Rules.
    However, time settings depend on ranks.

    5 TROUBLESOME DETAILS

    5.1 Colour Choice

    In even games typically the colours are randomly chosen. In
    handicap games black receives the handicap stones. -
    A manual method for randomly choosing colours is called
    nigiri. The older player hides a number of white stones
    taken from the bowl, the opponent takes one or two black
    stones to guess the parity, and the parity of the number of
    white stones is revealed. If the opponent guesses right,
    then he takes black, else he takes white.

    5.2 Pass Stones

    Some rules use pass stones. A passing player adds one own
    stone to the prisoners. As a consequence, captures before
    the game end can be resolved in alternation without any loss
    because any not answered approach move is compensated by one
    pass stone. With traditional territory scoring that uses no
    pass stones definition problems arise due to this missing
    option. Modern territory scoring or equivalence scoring use
    pass stones.

    5.3 Equivalence

    Area scoring and territory scoring are close because either
    intersections occupied by own stones or opposing prisoners
    are used. Essentially, every prisoner is a stone removed
    from some intersection. For area it scores one point less
    for the stone's player while for territory it scores one
    point more for his opponent. This is equal. Exact equality
    for the entire game must also consider passes by using pass
    stones and an equal number of moves by requiring white to
    pass last. This is done by equivalence scoring.

    5.4 Meaning of Agreement Removals

    Removals in an agreement phase under area scoring are fair
    because they may as well occur in alternation. Removing a
    stone due to agreement includes its then empty intersection
    and all adjacent empty intersections in the score. Removing
    a stone by means of alternation includes its then empty
    intersection and all adjacent newly occupied intersections
    in the score. -
    With traditional territory scoring this is not possible
    since stones on the board do not score. Thus final captures
    must occur after the game end due to attempted definitions
    in the rules.

    5.5 Practical Scoring Differences

    Since area scoring and modern territory scoring using pass
    stones are equal, correct play is the same for both. Apart
    from Japanese rules exceptions like not scoring empty
    intersections especially in asymmetrical coexistences or
    like a pass-for-ko-rule, traditional territory scoring can
    make a different winner in practically ca. every 10000th
    even game. This is so rare because of a parity feature
    combined with a scarcely odd number of intersections that
    are in coexistences but do not score for area at the game
    end. With area scoring a komi change from 1.5, 3.5, 5.5, ...
    to 2.5, 4.5, 6.5, ... almost always would not change the
    winner. So altough occupying the last empty intersections
    that would otherwise not score just before a game stop gains
    one point each, alternately doing so leaves a total
    advantage of at most one point. Due to the parity feature
    the player to get it is predetermined when this occupation
    starts. More importantly, one final ko is worth 1 point under
    traditional territory scoring but 2 or rarely 4 points under
    area scoring. Rare one-sided points in coexistences provide
    only area. Other practical differences are even rarer. Cute
    players include the stones in their endgame value counts
    during the middle of an area scoring game.

    5.6 Stone Scoring

    In ancient times stone scoring was popular. Only stones on
    the board are scored. Thus empty intersections surrounded by
    own stones are filled until necessary so called eyes remain.
    Disconnected stones require more eyes in total, the so
    called group tax.

    5.7 Old Ing Scoring

    Old Ing rules allowed fractional scores by assigning points
    to neutral empty regions due to the percentage of black and
    white stones surrounding every region.

    5.8 Primitive Rules

    They do not have passes. Alternation ends when a player
    loses due to no legal play. Games can be extremely long and
    include special strategies, so called pass fights. Primitive
    rules (also called no pass rules or Conway rules) can be
    useful in mathematics.

    5.9 Tradition

    Historically, exceptions arose, which some like as such
    especially together with Japanese style rules. So called
    sekis are excluded from the score. Special positions, termed
    precedents, have special rules. Modern Japanese rules have
    generalized a lot of them by a pass-for-ko-rule. After the
    game stop or after the game end and particularly in
    hypothetical play a stone captured in a possible 2-play cycle
    may not be recaptured unless before a pass is made that
    specifies the particular 2-play cycle.

    5.10 Positional / Situational Superko

    Positional superko prohibits a play that recreates a position.
    Situational superko refers to the situation, i.e. to the
    position together with the right to move. So a play is
    prohibited if it recreates a position while the same player
    has the right to move. In practice the differences are
    extremely rare.

    5.11 Handicap Recompensation

    With area scoring handicap stones beyond the first provide
    a potential extra area of one point per handicap stone. Komi
    for white may consider this. Recompensation, H-1 points for H
    handicap stones, is virtually only used together with
    American rules.

    5.12 Mathematics

    Go is a complete information game, i.e. at every move each
    player knows the entire game situation. Hence theoretically
    an algorithm could determine perfect play. However, due to
    the complexity of the game with N intersections, for which
    it is provably impossible to devise a polynomial time
    solution, perfect play or ideal komi are unknown. What one
    does know is that in a game without komi the first player wins
    or ties and that perfect play is independent of set komi. Many
    other propositions have been discovered, some of which
    describe the relation between area and territory scoring, solve
    tiny endgame positions or cyclical behaviour. -
    Go is a very complex game! According to John Tromp, the number
    of legal positions is:

    208168199381979984699478633344862770286522453884530548425 639456820927419612738015378525648451698519643907259916015 628128546089888314427129715319317557736620397247064840935

    For positional superko, no passes, and no resignation, the
    number of possible games is smaller than N**L(N) because L(N)
    also restricts the maximal number of moves per game and there
    are at most N possible intersections per move. (The sign ** is
    a text file notation for "to the power".) -
    Extremely modest estimates look like 10**N, which is based on
    an assumption of 10 reasonable intersections per move. A
    popular estimate for 19x19 go is 10**761, which must have
    originated from a typo and should be 10**361, if at all...
    These types of estimates are so popular because humans cannot
    even imagine the suggested number of atoms in the universe,
    10**80. For comparison, 3**361 is ca. 10**172.

    6 TOURNAMENT RULES

    6.1 Special Game Ends

    If the score considering the komi is zero, then the game is a
    tie and should be treated as 0.5 won games for each. Special
    rules or undue behaviour like sincere lateness might result
    in a referee declaring a win by forfeit, 0:0, or 1:1,
    whichever is most appropriate.

    6.2 Tournament Systems

    A tournament might consist of several stages, of which each
    has a seed and a system. A seed appropriately restricts
    participation, e.g. due to qualification. The most important
    systems are match, league, knockout, Swiss, McMahon. There
    are many others and hybrids. A system must fit the aims of a
    tournament. A sufficient number of rounds, a proper seed,
    and colour variation ensure a fair determination of the best
    player. -
    A match takes place between two players that either play a
    set number of games to see who wins more or a maximal number
    of games to see who wins a predetermined number of games
    first. In a league a small, usually even number of players
    performs a round-robin tournament, so that in each round all
    players play and every two players play against each other,
    one game e.g. A knockout preferably starts with a number of
    players that is a power of two. Losing players are eliminated,
    winning players continue until the winner remains. -
    In a Swiss system before each round each player's achieved
    number of wins is used to pair players with equal numbers as
    far as possible. So all players play all rounds and some time
    the best player will emerge. However, with greatly varying
    strengths too many rounds would be needed. So Swiss is only
    useful for particular events or handicap tournaments.
    McMahon is the refinement of Swiss. Before the start of the
    tournament all players are classified in rank groups, with
    ranks R from 0 to T. This means that one assumes a preceding
    Swiss tournament where every player has already won R games.
    Then in the McMahon tournament the strongest players, who
    deserve the rank T, compete for the top places. In practice,
    one uses a bar B, that is 1 or 2 ranks below T, so that all
    ranks above B are contracted to B and also players slightly
    weaker than the top players get their chance. All players in
    a McMahon play roughly equal opponents; if they win or lose,
    then the opponents will be stronger or weaker.

    6.3 Tie Breakers

    Tie breakers can refine pairings or results. Typically the
    first criterion is the number of wins (or McMahon points);
    all further criteria, if any, are tie breakers. They attempt
    a refinement where a low number of rounds and a tournament
    system do not guarantee sufficient distinction between
    players' achievements. However, they must be applied with
    care since they are only marginally better than coin tossing.
    Examples of tie breakers are direct comparison, which
    acknowledges the winner of a game between two players in
    question, and SOS, which is the Sum of Opponents' Scores. -
    The possible degree of quality of tie breakers is subject to
    discussion. It depends on tournament system, whether only the
    top or all players shall be distinguished, and other factors.
    An alternative to the usage of tie breakers for the final
    results ordering is issuing shared places for all players
    with the same number of wins (or McMahon points). - One must
    fairly assign tie breaker points for opponents missing in
    some round; enforcing participation is preferable especially
    for top players.

    6.4 Pairing

    Pairings must be fair, precise, and consider prior
    achievements during a tournament. One should consider colour
    balance and no pair twice, one might also aim at avoiding a
    pair of players from the same club or country, depending on
    a tournament's intentions. Pairings might be done manually
    in small tournaments; for most tournaments pairing programs
    should be used. These can create fair pairings convincingly,
    some even watch global balance.

    6.5 Thinking Times

    The age of killing each other by greater endurance has gone.
    Clocks are used to count each player's remaining thinking
    time. Typically, every game has a basic time and overtime
    periods. Exceeding a time limit loses a game. Basic time
    might be 9 hours for a professional top game, 10 minutes for
    a lightning game, or something in between that fits a
    tournament's intentions. An overtime period requires a fixed
    number of moves within a predetermined period, e.g. 1 move
    within 60 seconds. A move is finished by pressing the clock.
    - Many variants or other time systems exist, e.g., increasing
    numbers of moves in further overtime periods, penalty points
    for entering further periods, full usage of every overtime
    period, thinking time working like an hour glass, etc.

    6.6 Tournament Rules

    Every tournament uses an announced set of tournament rules.
    They especially specify the used set for the core rules of
    play, the tournament system, tie breakers, the pairing
    method, the winning criteria, compensation methods,
    thinking times, direction, jurisdiction, adjournment
    methods, penalities for being late, etc. Tournament rules
    often deal with details. Not everything can be predicted, so
    a sportsmanlike spirit is mentioned. Finally, it should be
    clear which of several rule sets takes precedence.

    6.7 Tournament Organization

    A regional tournament can be organized by a club. Big events
    can be held at the request of an association or federation,
    who also supervise. A tournament organization is responsible
    for providing a venue and playing material. It must be
    distinguished from the tournament director and his assistant
    directors, who perform the particular tasks of pairing,
    collecting results, and ensuring smooth running. Shared
    power furthermore demands independent referees.

    6.8 Jurisdiction

    Before the start of a tournament valid instances of a
    jurisdiction as well as the persons to be referees must be
    clear. Typically, for a tournament itself there is one
    referee as the first instance and a body of three referees
    as the second instance. For very peculiar cases a federation
    could have a third and final instance. Some tournament rules
    replace the second instance by a single person, called chief
    referee; to avoid confusion he ought not to judge as the
    first instance. Players should respect the referees' tough
    job of mediation or decision; referees should seriously
    enforce the rules.

    6.9 Prizes

    The first places of a tournament invoke major prizes. E.g.
    the first, second, third places might get 3/6, 2/6, 1/6 of
    the available money. In a tournament with many weaker
    players it is a good idea to provide some prizes for all
    other players that win most rounds as well. While prizes can
    be money, books, trophies, etc., one should remember that
    money is most universally accepted and trophies serve the
    media better than the winners. -
    On a related topic, a side event lottery must give equal
    chances to all participants. This is only achieved by using
    one lot for each.

    7 Links

    Most rules information, links, short rules: http://home.snafu.de/jasiek/rules.html

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Robert Jasiek@21:1/5 to All on Sat Jan 12 11:16:11 2019
    Title: Rules FAQ
    Author: Robert Jasiek <jasiek@snafu.de>
    Frequency: monthly
    Last Update: 2017-10-13; First Day: 1999-04-12
    Distribution: rec.games.go
    Copyright: free non-commercial usage for promotion

    0 CONTENTS

    1 Purpose of this Paper
    2 Information for Beginners
    3 Important Concepts
    4 Particular Rules
    5 Troublesome Details
    6 Tournament Rules
    7 Links

    1 PURPOSE OF THIS PAPER

    This paper is a basic reference for important rules terms,
    rules, and tournament rules. Beginners should read
    especially Chapters 2 and 3, players Chapters 3 to 5,
    tournament players and organizers Chapter 6.

    2 INFORMATION FOR BEGINNERS
    2.1 What Must I Know as a Beginner?

    The game is played on a grid board. Typically it has 19x19
    intersections, but 9x9 are also fine. Two players compete.
    The first player uses black stones, the other white.

    The players alternate. A player may play or pass. Playing
    is putting one's own stone on an empty intersection and
    removing any surrounded opposing stones. To avoid
    cycles, a play may not recreate any prior configuration of
    all stones on the board.

    Two successive passes end the game. Then the player with
    more intersections wins. Intersections are his if only his
    stones occupy or surround them.

    2.2 Which Rules do I Need as a Beginner?

    You can play with short rules as in 2.1. Other rules may
    be different, but the game is the same, i. e. strategy,
    tactics, and the score do not change. Extremely rare
    exceptions confirm this rule.

    The winner can be determined by area or by territory.
    Either includes empty intersections surrounded only by own
    stones. While area adds intersections occupied by own
    stones, territory adds opposing prisoners instead.

    All rules, except short rules, have further phases after
    alternation and before scoring. Towards a game end it is
    often clear which stones will be removed. The additional
    phases allow the players to agree on which stones shall be
    removed. Thereby final removals do not require alternation.

    Whether you score by area or by territory or whether you
    remove by alternation or by agreement should mainly depend
    on which rules are used by people you play with.

    2.3 Which Rules Should I Teach?

    One possibility is to use a board with 9x9 intersections,
    short rules as in 2.1, and count each player's score by
    using a finger to scan the board for his intersections.

    3 IMPORTANT CONCEPTS

    While strategy and tactics virtually remain the same,
    concepts vary in different rules. However, the following
    gives a comprehensive overview on standard terms.

    3.1 Stone, String

    The physical device that colours one intersection in a
    play is a STONE. Two intersections of the board are
    ADJACENT if they have a line but no intersection between
    them. Two intersections with either black, white, or no
    stones on them are CONNECTED if they are adjacent or if
    there is a chain of adjacent intersections of their type
    between them. A REGION consists of an intersection and
    any intersections connected to it. A black or white
    region is called a STRING.

    3.2 Surrounded

    An intersection of one colour is SURROUNDED by another
    colour if each leaving path reaches the other colour first
    after the one colour. Hereby it can only be surrounded
    black by white, white by black, empty by black, or empty
    by white. A region can be surrounded. For strings there is
    an alternative notion of no liberty (or breath). A LIBERTY
    of a string is an empty intersection adjacent to it. Thus
    a string is surrounded if and only if it has no liberty.

    3.3 Removal, Suicide

    A removal empties the intersections of surrounded stones
    if there are any. Hereby removal of opposing stones is
    executed first, if necessary. Rules may either require or
    forbid removal of own stones. This is called suicide or no
    suicide. In practice, suicide might be used for so called ko
    fights or in capturing races.

    3.4 Capture, Prisoner

    Rules that score territory call a removal a capture
    because all removed stones are seriously kept as prisoners.

    3.5 Move, Play, Pass

    The players have alternate turns. On each turn a player makes
    a move that is either a play or a pass. A play places one's
    own stone on an empty intersection. It can then include
    removal of surrounded stones, if any. A pass merely continues
    alternation by giving the opponent the next turn.

    3.6 Compensation

    The first move advantage by black can be compensated by
    compensation points (komi) that are added to the white score
    after the game end. Komi can be adjusted by 0.5 to avoid
    ties. Today integer values for komi for 19x19 boards
    typically range between 5 and 7. For 13x13 boards one should
    use 8, for 9x9 boards 6; however, there is no real consensus
    for small board komi values yet. -
    A weaker player (black) can get the right to place an agreed
    number of compensation stones (handicap) before white's first
    play. Rules may allow free or fixed handicap. Free handicap
    does not apply any restriction. Fixed handicap requires
    traditional placement on set intersections.

    3.7 Phases

    Normally, a game consists of the phases alternation,
    agreement, scoring. A game stop is between alternation and
    agreement, the game end is between agreement and scoring,
    and after scoring both players accept the counted score as
    the result. The main part of the game is the alternation
    phase. Special rules are invoked after it. Typically, two
    successive passes in alternation are the game stop and start
    the agreement phase. In it the players may agree on strings
    to be removed. If they agree, then they remove those strings
    from the board; this ends the game. Sometimes they might
    disagree, then no strings are removed but alternation is
    resumed as if the last game stop did not occur.

    3.8 Recreation

    The position is the pattern of black and white stones on the
    board. Without extra rule a position might be repeated
    infinitely. The easiest rule to prohibit this says: A play
    may not recreate a position. This refers to positions after
    completion of plays, i.e. after possible removals. The rule
    is called "superko". -
    Some rules use concepts different from superko. They combine
    a "2-play rule" with a "long cycle rule". The first says:
    Two successive plays may not recreate a position. The second
    says: If a position is recreated after more than two moves,
    then the game ends either immediately or, as a variant, as
    soon as the players agree, with the result "without result".
    In practice the 2-play rule is sufficient for almost all
    cases. It handles the relevant standard pattern of two
    adjacent intersections. For superko this is just a special
    application.

    3.9 Scoring

    The score is the result after the game end as defined by
    the rules. There are two different scoring methods: area
    scoring and territory scoring. Rules use one of them. Both
    give the same result in almost all cases and both evaluate
    the difference of the black and the white scores. A player's
    AREA score is the sum of intersections with own stones and
    of empty intersections surrounded only by own stones. Simply
    speaking, a player's TERRITORY score is the sum of empty
    intersections surrounded only by own stones and of prisoners
    of opposing colour. With both scoring methods empty
    intersections that are not surrounded by either black or
    white are neutral.

    3.10 Counting

    A score must be determined by some mechanical procedure in
    practice; this is called counting. There are various methods.
    Some rules prescribe one. A possible method is to use one's
    finger to count point by point. Other methods rearrange a lot
    of stones on the board.

    4 PARTICULAR RULES

    Rules vary extremely. However, in practice they often give
    the same result.

    4.1 Short Rules

    Examples of short rules are the Simple Rules or the
    Tromp-Taylor rules. They have no game stop and no agreement.
    Both are superfluous since necessary removals may already be
    performed in the alternation. Two successive passes end the
    game that is scored then. Short rules use area scoring,
    superko, and suicide. Further settings are left for
    tournament rules.

    4.2 American Rules

    These are used by the American Go Association. They use
    situational superko, no suicide, and 7.5 komi. They permit
    free or fixed handicap. Their most remarkable feature is to
    allow one of area scoring or territory scoring. Herefore
    pass stones (one prisoner compensates each pass) and white
    moving last always ensure the same result, regardless of the
    applied scoring method.

    4.3 Chinese Rules

    These are used in continental China and sometimes in other
    countries. Area scoring and no suicide are used.

    4.3.1 Official Chinese Rules

    In practice, ko rules roughly amount to a 2-play rule and a
    long cycle rule. The mentioned superko is overridden. The
    counting is a sophisticated half counting, where empty
    intersections and then after rearrangements stones of one
    colour are added to be compared with half the non-neutral
    intersections. The komi as a half komi is 3.75. In full
    counting, counts and komi would be twice as big.

    4.3.2 Simplified Chinese Rules

    Positional superko is used. A counting method is not
    prescribed. The full komi should be 7.5.

    4.4 Japanese Rules

    The differences mainly affect handling of late game phases
    but often do not alter scores. Japanese rules use some
    traditional territory scoring that attempts to exclude so
    called sekis. No suicide applies. The core of the ko rules
    is a 2-play rule and a long cycle rule. Typically, komi is
    6.5. Fixed handicap should be used. The counting is a
    sophisticated rearrangement of empty intersections and
    filling-in of prisoners.

    4.4.1 Game Finishing Process

    A game finishes with the following process: 1) So called
    dame (neutral points) and defensive moves (necessary
    connections etc. due to occupied dame) are filled.
    2) The hypothetical analysis, which presumes perfect play,
    determines so called life or death of each string and the
    scoring intersections. 3) Without making any approach moves,
    dead stones are removed from scoring intersections and added
    to the prisoners. 4) The score is counted. (2) and (3) do not
    allow to play out life and death since actually filling
    intersections costs points in Japanese rules.

    4.4.2 Official Japanese Rules

    There are the Japanese 1989 Rules, which are used in Japan
    and elsewhere, and the World Amateur Go Championships Rules,
    which are used in some particular tournaments. Korean rules
    are similar to Japanese rules but have a very different text
    and differ in rare positions. Official Japanese rules are
    very incomplete and have messy late game phases. E.g., the
    Japanese 1989 Rules allow filling of dame during alternation,
    after it, or both and have a so called ko-pass-rule for the
    hypothetical analysis. Now professional Japanese rules are
    explained precisely by a rules expert's interpretation called
    "the Japanese 2003 Rules".

    4.4.3 Simplified Japanese Rules

    As a recent invention, they are not used yet. They are
    complete and have clear late game phases. Filling of dame is
    done during alternation.

    4.4.4 Verbal Japanese Rules

    They are used for informal games in many countries and
    undefined, except that the game finishing process is used.
    In a tournament without any official rules of play, disputes
    are not solved due to the rules but with a referee.

    4.5 Ing Rules

    Ing rules use area scoring, suicide, 8 komi with black
    winning ties, and free handicap.

    4.5.1 Official Ing Rules

    The ko rules are a mess but somehow resemble superko.
    Details could fill books. The late game phases are specified
    insufficiently. The peculiar counting method requires 180
    stones of each colour throughout the game, fills any stones
    on the board after the game end, and leaves exactly one
    empty intersection, which determines the winner. The
    official rules are used in professional Taiwanese and some
    sponsored tournaments. Taiwanese amateurs have their own
    rules.

    4.5.2 Simplified Ing Rules

    Positional superko is used. A counting method is not
    prescribed. The late game phases are specified clearly. The
    simplified rules are used in EGF tournaments that are said
    to use Ing rules.

    4.6 New Zealand Rules

    Area scoring, suicide, situational superko, 7 komi, and free
    handicap are used.

    4.7 Go Server Rules

    Every go server has its own and often complicated rules, if
    any, so they cannot be given in detail here. Concerning
    "IGS rules", territory scoring, no suicide, a 2-play rule,
    fixed handicap, three game stopping passes, and captures in
    an agreement phase are used. Details about agreements and
    long cycles are not specified and lead to adjourned games in
    case of doubt. Komi is suggested but may be altered. Counting
    is automatic. "Yahoo" has territory scoring, no suicide, a
    2-play rule, two game stopping passes; long cycles and
    disagreements are not handled properly. On "email servers"
    players must agree on any rules. -
    Typically territory scoring on a go server means that neither
    points in any sekis are excluded nor pass stones are used.
    Thus while the Japanese seki exception is abandoned,
    disagreements about removals may lead to games without result
    since playing out can cost points.

    4.8 International Rules

    The international mailing list go-rules has proposed
    international rules, however, none are adopted yet. The core
    rules of play shall be clear, complete, and correct.
    Currently alternative texts are offered for suicide,
    recreation, and scoring. Especially unification of scoring
    methods is advocated.

    4.9 EGF Rules

    The EGF uses the Simplified Ing Rules with 8 komi (black
    wins ties) in Ing sponsored tournaments and the Nihon Kiin
    1989 Rules with 6.5 komi in Japanese/Korean sponsored
    tournaments. If significantly the European Go Championship
    has both kinds of sponsors, then boards 1-16 use the Nihon
    Kiin 1989 Rules and boards 17+ the Simplified Ing Rules.
    However, time settings depend on ranks.

    5 TROUBLESOME DETAILS

    5.1 Colour Choice

    In even games typically the colours are randomly chosen. In
    handicap games black receives the handicap stones. -
    A manual method for randomly choosing colours is called
    nigiri. The older player hides a number of white stones
    taken from the bowl, the opponent takes one or two black
    stones to guess the parity, and the parity of the number of
    white stones is revealed. If the opponent guesses right,
    then he takes black, else he takes white.

    5.2 Pass Stones

    Some rules use pass stones. A passing player adds one own
    stone to the prisoners. As a consequence, captures before
    the game end can be resolved in alternation without any loss
    because any not answered approach move is compensated by one
    pass stone. With traditional territory scoring that uses no
    pass stones definition problems arise due to this missing
    option. Modern territory scoring or equivalence scoring use
    pass stones.

    5.3 Equivalence

    Area scoring and territory scoring are close because either
    intersections occupied by own stones or opposing prisoners
    are used. Essentially, every prisoner is a stone removed
    from some intersection. For area it scores one point less
    for the stone's player while for territory it scores one
    point more for his opponent. This is equal. Exact equality
    for the entire game must also consider passes by using pass
    stones and an equal number of moves by requiring white to
    pass last. This is done by equivalence scoring.

    5.4 Meaning of Agreement Removals

    Removals in an agreement phase under area scoring are fair
    because they may as well occur in alternation. Removing a
    stone due to agreement includes its then empty intersection
    and all adjacent empty intersections in the score. Removing
    a stone by means of alternation includes its then empty
    intersection and all adjacent newly occupied intersections
    in the score. -
    With traditional territory scoring this is not possible
    since stones on the board do not score. Thus final captures
    must occur after the game end due to attempted definitions
    in the rules.

    5.5 Practical Scoring Differences

    Since area scoring and modern territory scoring using pass
    stones are equal, correct play is the same for both. Apart
    from Japanese rules exceptions like not scoring empty
    intersections especially in asymmetrical coexistences or
    like a pass-for-ko-rule, traditional territory scoring can
    make a different winner in practically ca. every 10000th
    even game. This is so rare because of a parity feature
    combined with a scarcely odd number of intersections that
    are in coexistences but do not score for area at the game
    end. With area scoring a komi change from 1.5, 3.5, 5.5, ...
    to 2.5, 4.5, 6.5, ... almost always would not change the
    winner. So altough occupying the last empty intersections
    that would otherwise not score just before a game stop gains
    one point each, alternately doing so leaves a total
    advantage of at most one point. Due to the parity feature
    the player to get it is predetermined when this occupation
    starts. More importantly, one final ko is worth 1 point under
    traditional territory scoring but 2 or rarely 4 points under
    area scoring. Rare one-sided points in coexistences provide
    only area. Other practical differences are even rarer. Cute
    players include the stones in their endgame value counts
    during the middle of an area scoring game.

    5.6 Stone Scoring

    In ancient times stone scoring was popular. Only stones on
    the board are scored. Thus empty intersections surrounded by
    own stones are filled until necessary so called eyes remain.
    Disconnected stones require more eyes in total, the so
    called group tax.

    5.7 Old Ing Scoring

    Old Ing rules allowed fractional scores by assigning points
    to neutral empty regions due to the percentage of black and
    white stones surrounding every region.

    5.8 Primitive Rules

    They do not have passes. Alternation ends when a player
    loses due to no legal play. Games can be extremely long and
    include special strategies, so called pass fights. Primitive
    rules (also called no pass rules or Conway rules) can be
    useful in mathematics.

    5.9 Tradition

    Historically, exceptions arose, which some like as such
    especially together with Japanese style rules. So called
    sekis are excluded from the score. Special positions, termed
    precedents, have special rules. Modern Japanese rules have
    generalized a lot of them by a pass-for-ko-rule. After the
    game stop or after the game end and particularly in
    hypothetical play a stone captured in a possible 2-play cycle
    may not be recaptured unless before a pass is made that
    specifies the particular 2-play cycle.

    5.10 Positional / Situational Superko

    Positional superko prohibits a play that recreates a position.
    Situational superko refers to the situation, i.e. to the
    position together with the right to move. So a play is
    prohibited if it recreates a position while the same player
    has the right to move. In practice the differences are
    extremely rare.

    5.11 Handicap Recompensation

    With area scoring handicap stones beyond the first provide
    a potential extra area of one point per handicap stone. Komi
    for white may consider this. Recompensation, H-1 points for H
    handicap stones, is virtually only used together with
    American rules.

    5.12 Mathematics

    Go is a complete information game, i.e. at every move each
    player knows the entire game situation. Hence theoretically
    an algorithm could determine perfect play. However, due to
    the complexity of the game with N intersections, for which
    it is provably impossible to devise a polynomial time
    solution, perfect play or ideal komi are unknown. What one
    does know is that in a game without komi the first player wins
    or ties and that perfect play is independent of set komi. Many
    other propositions have been discovered, some of which
    describe the relation between area and territory scoring, solve
    tiny endgame positions or cyclical behaviour. -
    Go is a very complex game! According to John Tromp, the number
    of legal positions is:

    208168199381979984699478633344862770286522453884530548425 639456820927419612738015378525648451698519643907259916015 628128546089888314427129715319317557736620397247064840935

    For positional superko, no passes, and no resignation, the
    number of possible games is smaller than N**L(N) because L(N)
    also restricts the maximal number of moves per game and there
    are at most N possible intersections per move. (The sign ** is
    a text file notation for "to the power".) -
    Extremely modest estimates look like 10**N, which is based on
    an assumption of 10 reasonable intersections per move. A
    popular estimate for 19x19 go is 10**761, which must have
    originated from a typo and should be 10**361, if at all...
    These types of estimates are so popular because humans cannot
    even imagine the suggested number of atoms in the universe,
    10**80. For comparison, 3**361 is ca. 10**172.

    6 TOURNAMENT RULES

    6.1 Special Game Ends

    If the score considering the komi is zero, then the game is a
    tie and should be treated as 0.5 won games for each. Special
    rules or undue behaviour like sincere lateness might result
    in a referee declaring a win by forfeit, 0:0, or 1:1,
    whichever is most appropriate.

    6.2 Tournament Systems

    A tournament might consist of several stages, of which each
    has a seed and a system. A seed appropriately restricts
    participation, e.g. due to qualification. The most important
    systems are match, league, knockout, Swiss, McMahon. There
    are many others and hybrids. A system must fit the aims of a
    tournament. A sufficient number of rounds, a proper seed,
    and colour variation ensure a fair determination of the best
    player. -
    A match takes place between two players that either play a
    set number of games to see who wins more or a maximal number
    of games to see who wins a predetermined number of games
    first. In a league a small, usually even number of players
    performs a round-robin tournament, so that in each round all
    players play and every two players play against each other,
    one game e.g. A knockout preferably starts with a number of
    players that is a power of two. Losing players are eliminated,
    winning players continue until the winner remains. -
    In a Swiss system before each round each player's achieved
    number of wins is used to pair players with equal numbers as
    far as possible. So all players play all rounds and some time
    the best player will emerge. However, with greatly varying
    strengths too many rounds would be needed. So Swiss is only
    useful for particular events or handicap tournaments.
    McMahon is the refinement of Swiss. Before the start of the
    tournament all players are classified in rank groups, with
    ranks R from 0 to T. This means that one assumes a preceding
    Swiss tournament where every player has already won R games.
    Then in the McMahon tournament the strongest players, who
    deserve the rank T, compete for the top places. In practice,
    one uses a bar B, that is 1 or 2 ranks below T, so that all
    ranks above B are contracted to B and also players slightly
    weaker than the top players get their chance. All players in
    a McMahon play roughly equal opponents; if they win or lose,
    then the opponents will be stronger or weaker.

    6.3 Tie Breakers

    Tie breakers can refine pairings or results. Typically the
    first criterion is the number of wins (or McMahon points);
    all further criteria, if any, are tie breakers. They attempt
    a refinement where a low number of rounds and a tournament
    system do not guarantee sufficient distinction between
    players' achievements. However, they must be applied with
    care since they are only marginally better than coin tossing.
    Examples of tie breakers are direct comparison, which
    acknowledges the winner of a game between two players in
    question, and SOS, which is the Sum of Opponents' Scores. -
    The possible degree of quality of tie breakers is subject to
    discussion. It depends on tournament system, whether only the
    top or all players shall be distinguished, and other factors.
    An alternative to the usage of tie breakers for the final
    results ordering is issuing shared places for all players
    with the same number of wins (or McMahon points). - One must
    fairly assign tie breaker points for opponents missing in
    some round; enforcing participation is preferable especially
    for top players.

    6.4 Pairing

    Pairings must be fair, precise, and consider prior
    achievements during a tournament. One should consider colour
    balance and no pair twice, one might also aim at avoiding a
    pair of players from the same club or country, depending on
    a tournament's intentions. Pairings might be done manually
    in small tournaments; for most tournaments pairing programs
    should be used. These can create fair pairings convincingly,
    some even watch global balance.

    6.5 Thinking Times

    The age of killing each other by greater endurance has gone.
    Clocks are used to count each player's remaining thinking
    time. Typically, every game has a basic time and overtime
    periods. Exceeding a time limit loses a game. Basic time
    might be 9 hours for a professional top game, 10 minutes for
    a lightning game, or something in between that fits a
    tournament's intentions. An overtime period requires a fixed
    number of moves within a predetermined period, e.g. 1 move
    within 60 seconds. A move is finished by pressing the clock.
    - Many variants or other time systems exist, e.g., increasing
    numbers of moves in further overtime periods, penalty points
    for entering further periods, full usage of every overtime
    period, thinking time working like an hour glass, etc.

    6.6 Tournament Rules

    Every tournament uses an announced set of tournament rules.
    They especially specify the used set for the core rules of
    play, the tournament system, tie breakers, the pairing
    method, the winning criteria, compensation methods,
    thinking times, direction, jurisdiction, adjournment
    methods, penalities for being late, etc. Tournament rules
    often deal with details. Not everything can be predicted, so
    a sportsmanlike spirit is mentioned. Finally, it should be
    clear which of several rule sets takes precedence.

    6.7 Tournament Organization

    A regional tournament can be organized by a club. Big events
    can be held at the request of an association or federation,
    who also supervise. A tournament organization is responsible
    for providing a venue and playing material. It must be
    distinguished from the tournament director and his assistant
    directors, who perform the particular tasks of pairing,
    collecting results, and ensuring smooth running. Shared
    power furthermore demands independent referees.

    6.8 Jurisdiction

    Before the start of a tournament valid instances of a
    jurisdiction as well as the persons to be referees must be
    clear. Typically, for a tournament itself there is one
    referee as the first instance and a body of three referees
    as the second instance. For very peculiar cases a federation
    could have a third and final instance. Some tournament rules
    replace the second instance by a single person, called chief
    referee; to avoid confusion he ought not to judge as the
    first instance. Players should respect the referees' tough
    job of mediation or decision; referees should seriously
    enforce the rules.

    6.9 Prizes

    The first places of a tournament invoke major prizes. E.g.
    the first, second, third places might get 3/6, 2/6, 1/6 of
    the available money. In a tournament with many weaker
    players it is a good idea to provide some prizes for all
    other players that win most rounds as well. While prizes can
    be money, books, trophies, etc., one should remember that
    money is most universally accepted and trophies serve the
    media better than the winners. -
    On a related topic, a side event lottery must give equal
    chances to all participants. This is only achieved by using
    one lot for each.

    7 Links

    Most rules information, links, short rules: http://home.snafu.de/jasiek/rules.html

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Robert Jasiek@21:1/5 to All on Tue Feb 12 08:47:02 2019
    Title: Rules FAQ
    Author: Robert Jasiek <jasiek@snafu.de>
    Frequency: monthly
    Last Update: 2017-10-13; First Day: 1999-04-12
    Distribution: rec.games.go
    Copyright: free non-commercial usage for promotion

    0 CONTENTS

    1 Purpose of this Paper
    2 Information for Beginners
    3 Important Concepts
    4 Particular Rules
    5 Troublesome Details
    6 Tournament Rules
    7 Links

    1 PURPOSE OF THIS PAPER

    This paper is a basic reference for important rules terms,
    rules, and tournament rules. Beginners should read
    especially Chapters 2 and 3, players Chapters 3 to 5,
    tournament players and organizers Chapter 6.

    2 INFORMATION FOR BEGINNERS
    2.1 What Must I Know as a Beginner?

    The game is played on a grid board. Typically it has 19x19
    intersections, but 9x9 are also fine. Two players compete.
    The first player uses black stones, the other white.

    The players alternate. A player may play or pass. Playing
    is putting one's own stone on an empty intersection and
    removing any surrounded opposing stones. To avoid
    cycles, a play may not recreate any prior configuration of
    all stones on the board.

    Two successive passes end the game. Then the player with
    more intersections wins. Intersections are his if only his
    stones occupy or surround them.

    2.2 Which Rules do I Need as a Beginner?

    You can play with short rules as in 2.1. Other rules may
    be different, but the game is the same, i. e. strategy,
    tactics, and the score do not change. Extremely rare
    exceptions confirm this rule.

    The winner can be determined by area or by territory.
    Either includes empty intersections surrounded only by own
    stones. While area adds intersections occupied by own
    stones, territory adds opposing prisoners instead.

    All rules, except short rules, have further phases after
    alternation and before scoring. Towards a game end it is
    often clear which stones will be removed. The additional
    phases allow the players to agree on which stones shall be
    removed. Thereby final removals do not require alternation.

    Whether you score by area or by territory or whether you
    remove by alternation or by agreement should mainly depend
    on which rules are used by people you play with.

    2.3 Which Rules Should I Teach?

    One possibility is to use a board with 9x9 intersections,
    short rules as in 2.1, and count each player's score by
    using a finger to scan the board for his intersections.

    3 IMPORTANT CONCEPTS

    While strategy and tactics virtually remain the same,
    concepts vary in different rules. However, the following
    gives a comprehensive overview on standard terms.

    3.1 Stone, String

    The physical device that colours one intersection in a
    play is a STONE. Two intersections of the board are
    ADJACENT if they have a line but no intersection between
    them. Two intersections with either black, white, or no
    stones on them are CONNECTED if they are adjacent or if
    there is a chain of adjacent intersections of their type
    between them. A REGION consists of an intersection and
    any intersections connected to it. A black or white
    region is called a STRING.

    3.2 Surrounded

    An intersection of one colour is SURROUNDED by another
    colour if each leaving path reaches the other colour first
    after the one colour. Hereby it can only be surrounded
    black by white, white by black, empty by black, or empty
    by white. A region can be surrounded. For strings there is
    an alternative notion of no liberty (or breath). A LIBERTY
    of a string is an empty intersection adjacent to it. Thus
    a string is surrounded if and only if it has no liberty.

    3.3 Removal, Suicide

    A removal empties the intersections of surrounded stones
    if there are any. Hereby removal of opposing stones is
    executed first, if necessary. Rules may either require or
    forbid removal of own stones. This is called suicide or no
    suicide. In practice, suicide might be used for so called ko
    fights or in capturing races.

    3.4 Capture, Prisoner

    Rules that score territory call a removal a capture
    because all removed stones are seriously kept as prisoners.

    3.5 Move, Play, Pass

    The players have alternate turns. On each turn a player makes
    a move that is either a play or a pass. A play places one's
    own stone on an empty intersection. It can then include
    removal of surrounded stones, if any. A pass merely continues
    alternation by giving the opponent the next turn.

    3.6 Compensation

    The first move advantage by black can be compensated by
    compensation points (komi) that are added to the white score
    after the game end. Komi can be adjusted by 0.5 to avoid
    ties. Today integer values for komi for 19x19 boards
    typically range between 5 and 7. For 13x13 boards one should
    use 8, for 9x9 boards 6; however, there is no real consensus
    for small board komi values yet. -
    A weaker player (black) can get the right to place an agreed
    number of compensation stones (handicap) before white's first
    play. Rules may allow free or fixed handicap. Free handicap
    does not apply any restriction. Fixed handicap requires
    traditional placement on set intersections.

    3.7 Phases

    Normally, a game consists of the phases alternation,
    agreement, scoring. A game stop is between alternation and
    agreement, the game end is between agreement and scoring,
    and after scoring both players accept the counted score as
    the result. The main part of the game is the alternation
    phase. Special rules are invoked after it. Typically, two
    successive passes in alternation are the game stop and start
    the agreement phase. In it the players may agree on strings
    to be removed. If they agree, then they remove those strings
    from the board; this ends the game. Sometimes they might
    disagree, then no strings are removed but alternation is
    resumed as if the last game stop did not occur.

    3.8 Recreation

    The position is the pattern of black and white stones on the
    board. Without extra rule a position might be repeated
    infinitely. The easiest rule to prohibit this says: A play
    may not recreate a position. This refers to positions after
    completion of plays, i.e. after possible removals. The rule
    is called "superko". -
    Some rules use concepts different from superko. They combine
    a "2-play rule" with a "long cycle rule". The first says:
    Two successive plays may not recreate a position. The second
    says: If a position is recreated after more than two moves,
    then the game ends either immediately or, as a variant, as
    soon as the players agree, with the result "without result".
    In practice the 2-play rule is sufficient for almost all
    cases. It handles the relevant standard pattern of two
    adjacent intersections. For superko this is just a special
    application.

    3.9 Scoring

    The score is the result after the game end as defined by
    the rules. There are two different scoring methods: area
    scoring and territory scoring. Rules use one of them. Both
    give the same result in almost all cases and both evaluate
    the difference of the black and the white scores. A player's
    AREA score is the sum of intersections with own stones and
    of empty intersections surrounded only by own stones. Simply
    speaking, a player's TERRITORY score is the sum of empty
    intersections surrounded only by own stones and of prisoners
    of opposing colour. With both scoring methods empty
    intersections that are not surrounded by either black or
    white are neutral.

    3.10 Counting

    A score must be determined by some mechanical procedure in
    practice; this is called counting. There are various methods.
    Some rules prescribe one. A possible method is to use one's
    finger to count point by point. Other methods rearrange a lot
    of stones on the board.

    4 PARTICULAR RULES

    Rules vary extremely. However, in practice they often give
    the same result.

    4.1 Short Rules

    Examples of short rules are the Simple Rules or the
    Tromp-Taylor rules. They have no game stop and no agreement.
    Both are superfluous since necessary removals may already be
    performed in the alternation. Two successive passes end the
    game that is scored then. Short rules use area scoring,
    superko, and suicide. Further settings are left for
    tournament rules.

    4.2 American Rules

    These are used by the American Go Association. They use
    situational superko, no suicide, and 7.5 komi. They permit
    free or fixed handicap. Their most remarkable feature is to
    allow one of area scoring or territory scoring. Herefore
    pass stones (one prisoner compensates each pass) and white
    moving last always ensure the same result, regardless of the
    applied scoring method.

    4.3 Chinese Rules

    These are used in continental China and sometimes in other
    countries. Area scoring and no suicide are used.

    4.3.1 Official Chinese Rules

    In practice, ko rules roughly amount to a 2-play rule and a
    long cycle rule. The mentioned superko is overridden. The
    counting is a sophisticated half counting, where empty
    intersections and then after rearrangements stones of one
    colour are added to be compared with half the non-neutral
    intersections. The komi as a half komi is 3.75. In full
    counting, counts and komi would be twice as big.

    4.3.2 Simplified Chinese Rules

    Positional superko is used. A counting method is not
    prescribed. The full komi should be 7.5.

    4.4 Japanese Rules

    The differences mainly affect handling of late game phases
    but often do not alter scores. Japanese rules use some
    traditional territory scoring that attempts to exclude so
    called sekis. No suicide applies. The core of the ko rules
    is a 2-play rule and a long cycle rule. Typically, komi is
    6.5. Fixed handicap should be used. The counting is a
    sophisticated rearrangement of empty intersections and
    filling-in of prisoners.

    4.4.1 Game Finishing Process

    A game finishes with the following process: 1) So called
    dame (neutral points) and defensive moves (necessary
    connections etc. due to occupied dame) are filled.
    2) The hypothetical analysis, which presumes perfect play,
    determines so called life or death of each string and the
    scoring intersections. 3) Without making any approach moves,
    dead stones are removed from scoring intersections and added
    to the prisoners. 4) The score is counted. (2) and (3) do not
    allow to play out life and death since actually filling
    intersections costs points in Japanese rules.

    4.4.2 Official Japanese Rules

    There are the Japanese 1989 Rules, which are used in Japan
    and elsewhere, and the World Amateur Go Championships Rules,
    which are used in some particular tournaments. Korean rules
    are similar to Japanese rules but have a very different text
    and differ in rare positions. Official Japanese rules are
    very incomplete and have messy late game phases. E.g., the
    Japanese 1989 Rules allow filling of dame during alternation,
    after it, or both and have a so called ko-pass-rule for the
    hypothetical analysis. Now professional Japanese rules are
    explained precisely by a rules expert's interpretation called
    "the Japanese 2003 Rules".

    4.4.3 Simplified Japanese Rules

    As a recent invention, they are not used yet. They are
    complete and have clear late game phases. Filling of dame is
    done during alternation.

    4.4.4 Verbal Japanese Rules

    They are used for informal games in many countries and
    undefined, except that the game finishing process is used.
    In a tournament without any official rules of play, disputes
    are not solved due to the rules but with a referee.

    4.5 Ing Rules

    Ing rules use area scoring, suicide, 8 komi with black
    winning ties, and free handicap.

    4.5.1 Official Ing Rules

    The ko rules are a mess but somehow resemble superko.
    Details could fill books. The late game phases are specified
    insufficiently. The peculiar counting method requires 180
    stones of each colour throughout the game, fills any stones
    on the board after the game end, and leaves exactly one
    empty intersection, which determines the winner. The
    official rules are used in professional Taiwanese and some
    sponsored tournaments. Taiwanese amateurs have their own
    rules.

    4.5.2 Simplified Ing Rules

    Positional superko is used. A counting method is not
    prescribed. The late game phases are specified clearly. The
    simplified rules are used in EGF tournaments that are said
    to use Ing rules.

    4.6 New Zealand Rules

    Area scoring, suicide, situational superko, 7 komi, and free
    handicap are used.

    4.7 Go Server Rules

    Every go server has its own and often complicated rules, if
    any, so they cannot be given in detail here. Concerning
    "IGS rules", territory scoring, no suicide, a 2-play rule,
    fixed handicap, three game stopping passes, and captures in
    an agreement phase are used. Details about agreements and
    long cycles are not specified and lead to adjourned games in
    case of doubt. Komi is suggested but may be altered. Counting
    is automatic. "Yahoo" has territory scoring, no suicide, a
    2-play rule, two game stopping passes; long cycles and
    disagreements are not handled properly. On "email servers"
    players must agree on any rules. -
    Typically territory scoring on a go server means that neither
    points in any sekis are excluded nor pass stones are used.
    Thus while the Japanese seki exception is abandoned,
    disagreements about removals may lead to games without result
    since playing out can cost points.

    4.8 International Rules

    The international mailing list go-rules has proposed
    international rules, however, none are adopted yet. The core
    rules of play shall be clear, complete, and correct.
    Currently alternative texts are offered for suicide,
    recreation, and scoring. Especially unification of scoring
    methods is advocated.

    4.9 EGF Rules

    The EGF uses the Simplified Ing Rules with 8 komi (black
    wins ties) in Ing sponsored tournaments and the Nihon Kiin
    1989 Rules with 6.5 komi in Japanese/Korean sponsored
    tournaments. If significantly the European Go Championship
    has both kinds of sponsors, then boards 1-16 use the Nihon
    Kiin 1989 Rules and boards 17+ the Simplified Ing Rules.
    However, time settings depend on ranks.

    5 TROUBLESOME DETAILS

    5.1 Colour Choice

    In even games typically the colours are randomly chosen. In
    handicap games black receives the handicap stones. -
    A manual method for randomly choosing colours is called
    nigiri. The older player hides a number of white stones
    taken from the bowl, the opponent takes one or two black
    stones to guess the parity, and the parity of the number of
    white stones is revealed. If the opponent guesses right,
    then he takes black, else he takes white.

    5.2 Pass Stones

    Some rules use pass stones. A passing player adds one own
    stone to the prisoners. As a consequence, captures before
    the game end can be resolved in alternation without any loss
    because any not answered approach move is compensated by one
    pass stone. With traditional territory scoring that uses no
    pass stones definition problems arise due to this missing
    option. Modern territory scoring or equivalence scoring use
    pass stones.

    5.3 Equivalence

    Area scoring and territory scoring are close because either
    intersections occupied by own stones or opposing prisoners
    are used. Essentially, every prisoner is a stone removed
    from some intersection. For area it scores one point less
    for the stone's player while for territory it scores one
    point more for his opponent. This is equal. Exact equality
    for the entire game must also consider passes by using pass
    stones and an equal number of moves by requiring white to
    pass last. This is done by equivalence scoring.

    5.4 Meaning of Agreement Removals

    Removals in an agreement phase under area scoring are fair
    because they may as well occur in alternation. Removing a
    stone due to agreement includes its then empty intersection
    and all adjacent empty intersections in the score. Removing
    a stone by means of alternation includes its then empty
    intersection and all adjacent newly occupied intersections
    in the score. -
    With traditional territory scoring this is not possible
    since stones on the board do not score. Thus final captures
    must occur after the game end due to attempted definitions
    in the rules.

    5.5 Practical Scoring Differences

    Since area scoring and modern territory scoring using pass
    stones are equal, correct play is the same for both. Apart
    from Japanese rules exceptions like not scoring empty
    intersections especially in asymmetrical coexistences or
    like a pass-for-ko-rule, traditional territory scoring can
    make a different winner in practically ca. every 10000th
    even game. This is so rare because of a parity feature
    combined with a scarcely odd number of intersections that
    are in coexistences but do not score for area at the game
    end. With area scoring a komi change from 1.5, 3.5, 5.5, ...
    to 2.5, 4.5, 6.5, ... almost always would not change the
    winner. So altough occupying the last empty intersections
    that would otherwise not score just before a game stop gains
    one point each, alternately doing so leaves a total
    advantage of at most one point. Due to the parity feature
    the player to get it is predetermined when this occupation
    starts. More importantly, one final ko is worth 1 point under
    traditional territory scoring but 2 or rarely 4 points under
    area scoring. Rare one-sided points in coexistences provide
    only area. Other practical differences are even rarer. Cute
    players include the stones in their endgame value counts
    during the middle of an area scoring game.

    5.6 Stone Scoring

    In ancient times stone scoring was popular. Only stones on
    the board are scored. Thus empty intersections surrounded by
    own stones are filled until necessary so called eyes remain.
    Disconnected stones require more eyes in total, the so
    called group tax.

    5.7 Old Ing Scoring

    Old Ing rules allowed fractional scores by assigning points
    to neutral empty regions due to the percentage of black and
    white stones surrounding every region.

    5.8 Primitive Rules

    They do not have passes. Alternation ends when a player
    loses due to no legal play. Games can be extremely long and
    include special strategies, so called pass fights. Primitive
    rules (also called no pass rules or Conway rules) can be
    useful in mathematics.

    5.9 Tradition

    Historically, exceptions arose, which some like as such
    especially together with Japanese style rules. So called
    sekis are excluded from the score. Special positions, termed
    precedents, have special rules. Modern Japanese rules have
    generalized a lot of them by a pass-for-ko-rule. After the
    game stop or after the game end and particularly in
    hypothetical play a stone captured in a possible 2-play cycle
    may not be recaptured unless before a pass is made that
    specifies the particular 2-play cycle.

    5.10 Positional / Situational Superko

    Positional superko prohibits a play that recreates a position.
    Situational superko refers to the situation, i.e. to the
    position together with the right to move. So a play is
    prohibited if it recreates a position while the same player
    has the right to move. In practice the differences are
    extremely rare.

    5.11 Handicap Recompensation

    With area scoring handicap stones beyond the first provide
    a potential extra area of one point per handicap stone. Komi
    for white may consider this. Recompensation, H-1 points for H
    handicap stones, is virtually only used together with
    American rules.

    5.12 Mathematics

    Go is a complete information game, i.e. at every move each
    player knows the entire game situation. Hence theoretically
    an algorithm could determine perfect play. However, due to
    the complexity of the game with N intersections, for which
    it is provably impossible to devise a polynomial time
    solution, perfect play or ideal komi are unknown. What one
    does know is that in a game without komi the first player wins
    or ties and that perfect play is independent of set komi. Many
    other propositions have been discovered, some of which
    describe the relation between area and territory scoring, solve
    tiny endgame positions or cyclical behaviour. -
    Go is a very complex game! According to John Tromp, the number
    of legal positions is:

    208168199381979984699478633344862770286522453884530548425 639456820927419612738015378525648451698519643907259916015 628128546089888314427129715319317557736620397247064840935

    For positional superko, no passes, and no resignation, the
    number of possible games is smaller than N**L(N) because L(N)
    also restricts the maximal number of moves per game and there
    are at most N possible intersections per move. (The sign ** is
    a text file notation for "to the power".) -
    Extremely modest estimates look like 10**N, which is based on
    an assumption of 10 reasonable intersections per move. A
    popular estimate for 19x19 go is 10**761, which must have
    originated from a typo and should be 10**361, if at all...
    These types of estimates are so popular because humans cannot
    even imagine the suggested number of atoms in the universe,
    10**80. For comparison, 3**361 is ca. 10**172.

    6 TOURNAMENT RULES

    6.1 Special Game Ends

    If the score considering the komi is zero, then the game is a
    tie and should be treated as 0.5 won games for each. Special
    rules or undue behaviour like sincere lateness might result
    in a referee declaring a win by forfeit, 0:0, or 1:1,
    whichever is most appropriate.

    6.2 Tournament Systems

    A tournament might consist of several stages, of which each
    has a seed and a system. A seed appropriately restricts
    participation, e.g. due to qualification. The most important
    systems are match, league, knockout, Swiss, McMahon. There
    are many others and hybrids. A system must fit the aims of a
    tournament. A sufficient number of rounds, a proper seed,
    and colour variation ensure a fair determination of the best
    player. -
    A match takes place between two players that either play a
    set number of games to see who wins more or a maximal number
    of games to see who wins a predetermined number of games
    first. In a league a small, usually even number of players
    performs a round-robin tournament, so that in each round all
    players play and every two players play against each other,
    one game e.g. A knockout preferably starts with a number of
    players that is a power of two. Losing players are eliminated,
    winning players continue until the winner remains. -
    In a Swiss system before each round each player's achieved
    number of wins is used to pair players with equal numbers as
    far as possible. So all players play all rounds and some time
    the best player will emerge. However, with greatly varying
    strengths too many rounds would be needed. So Swiss is only
    useful for particular events or handicap tournaments.
    McMahon is the refinement of Swiss. Before the start of the
    tournament all players are classified in rank groups, with
    ranks R from 0 to T. This means that one assumes a preceding
    Swiss tournament where every player has already won R games.
    Then in the McMahon tournament the strongest players, who
    deserve the rank T, compete for the top places. In practice,
    one uses a bar B, that is 1 or 2 ranks below T, so that all
    ranks above B are contracted to B and also players slightly
    weaker than the top players get their chance. All players in
    a McMahon play roughly equal opponents; if they win or lose,
    then the opponents will be stronger or weaker.

    6.3 Tie Breakers

    Tie breakers can refine pairings or results. Typically the
    first criterion is the number of wins (or McMahon points);
    all further criteria, if any, are tie breakers. They attempt
    a refinement where a low number of rounds and a tournament
    system do not guarantee sufficient distinction between
    players' achievements. However, they must be applied with
    care since they are only marginally better than coin tossing.
    Examples of tie breakers are direct comparison, which
    acknowledges the winner of a game between two players in
    question, and SOS, which is the Sum of Opponents' Scores. -
    The possible degree of quality of tie breakers is subject to
    discussion. It depends on tournament system, whether only the
    top or all players shall be distinguished, and other factors.
    An alternative to the usage of tie breakers for the final
    results ordering is issuing shared places for all players
    with the same number of wins (or McMahon points). - One must
    fairly assign tie breaker points for opponents missing in
    some round; enforcing participation is preferable especially
    for top players.

    6.4 Pairing

    Pairings must be fair, precise, and consider prior
    achievements during a tournament. One should consider colour
    balance and no pair twice, one might also aim at avoiding a
    pair of players from the same club or country, depending on
    a tournament's intentions. Pairings might be done manually
    in small tournaments; for most tournaments pairing programs
    should be used. These can create fair pairings convincingly,
    some even watch global balance.

    6.5 Thinking Times

    The age of killing each other by greater endurance has gone.
    Clocks are used to count each player's remaining thinking
    time. Typically, every game has a basic time and overtime
    periods. Exceeding a time limit loses a game. Basic time
    might be 9 hours for a professional top game, 10 minutes for
    a lightning game, or something in between that fits a
    tournament's intentions. An overtime period requires a fixed
    number of moves within a predetermined period, e.g. 1 move
    within 60 seconds. A move is finished by pressing the clock.
    - Many variants or other time systems exist, e.g., increasing
    numbers of moves in further overtime periods, penalty points
    for entering further periods, full usage of every overtime
    period, thinking time working like an hour glass, etc.

    6.6 Tournament Rules

    Every tournament uses an announced set of tournament rules.
    They especially specify the used set for the core rules of
    play, the tournament system, tie breakers, the pairing
    method, the winning criteria, compensation methods,
    thinking times, direction, jurisdiction, adjournment
    methods, penalities for being late, etc. Tournament rules
    often deal with details. Not everything can be predicted, so
    a sportsmanlike spirit is mentioned. Finally, it should be
    clear which of several rule sets takes precedence.

    6.7 Tournament Organization

    A regional tournament can be organized by a club. Big events
    can be held at the request of an association or federation,
    who also supervise. A tournament organization is responsible
    for providing a venue and playing material. It must be
    distinguished from the tournament director and his assistant
    directors, who perform the particular tasks of pairing,
    collecting results, and ensuring smooth running. Shared
    power furthermore demands independent referees.

    6.8 Jurisdiction

    Before the start of a tournament valid instances of a
    jurisdiction as well as the persons to be referees must be
    clear. Typically, for a tournament itself there is one
    referee as the first instance and a body of three referees
    as the second instance. For very peculiar cases a federation
    could have a third and final instance. Some tournament rules
    replace the second instance by a single person, called chief
    referee; to avoid confusion he ought not to judge as the
    first instance. Players should respect the referees' tough
    job of mediation or decision; referees should seriously
    enforce the rules.

    6.9 Prizes

    The first places of a tournament invoke major prizes. E.g.
    the first, second, third places might get 3/6, 2/6, 1/6 of
    the available money. In a tournament with many weaker
    players it is a good idea to provide some prizes for all
    other players that win most rounds as well. While prizes can
    be money, books, trophies, etc., one should remember that
    money is most universally accepted and trophies serve the
    media better than the winners. -
    On a related topic, a side event lottery must give equal
    chances to all participants. This is only achieved by using
    one lot for each.

    7 Links

    Most rules information, links, short rules: http://home.snafu.de/jasiek/rules.html

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Robert Jasiek@21:1/5 to All on Fri Apr 12 14:42:16 2019
    Title: Rules FAQ
    Author: Robert Jasiek <jasiek@snafu.de>
    Frequency: monthly
    Last Update: 2017-10-13; First Day: 1999-04-12
    Distribution: rec.games.go
    Copyright: free non-commercial usage for promotion

    0 CONTENTS

    1 Purpose of this Paper
    2 Information for Beginners
    3 Important Concepts
    4 Particular Rules
    5 Troublesome Details
    6 Tournament Rules
    7 Links

    1 PURPOSE OF THIS PAPER

    This paper is a basic reference for important rules terms,
    rules, and tournament rules. Beginners should read
    especially Chapters 2 and 3, players Chapters 3 to 5,
    tournament players and organizers Chapter 6.

    2 INFORMATION FOR BEGINNERS
    2.1 What Must I Know as a Beginner?

    The game is played on a grid board. Typically it has 19x19
    intersections, but 9x9 are also fine. Two players compete.
    The first player uses black stones, the other white.

    The players alternate. A player may play or pass. Playing
    is putting one's own stone on an empty intersection and
    removing any surrounded opposing stones. To avoid
    cycles, a play may not recreate any prior configuration of
    all stones on the board.

    Two successive passes end the game. Then the player with
    more intersections wins. Intersections are his if only his
    stones occupy or surround them.

    2.2 Which Rules do I Need as a Beginner?

    You can play with short rules as in 2.1. Other rules may
    be different, but the game is the same, i. e. strategy,
    tactics, and the score do not change. Extremely rare
    exceptions confirm this rule.

    The winner can be determined by area or by territory.
    Either includes empty intersections surrounded only by own
    stones. While area adds intersections occupied by own
    stones, territory adds opposing prisoners instead.

    All rules, except short rules, have further phases after
    alternation and before scoring. Towards a game end it is
    often clear which stones will be removed. The additional
    phases allow the players to agree on which stones shall be
    removed. Thereby final removals do not require alternation.

    Whether you score by area or by territory or whether you
    remove by alternation or by agreement should mainly depend
    on which rules are used by people you play with.

    2.3 Which Rules Should I Teach?

    One possibility is to use a board with 9x9 intersections,
    short rules as in 2.1, and count each player's score by
    using a finger to scan the board for his intersections.

    3 IMPORTANT CONCEPTS

    While strategy and tactics virtually remain the same,
    concepts vary in different rules. However, the following
    gives a comprehensive overview on standard terms.

    3.1 Stone, String

    The physical device that colours one intersection in a
    play is a STONE. Two intersections of the board are
    ADJACENT if they have a line but no intersection between
    them. Two intersections with either black, white, or no
    stones on them are CONNECTED if they are adjacent or if
    there is a chain of adjacent intersections of their type
    between them. A REGION consists of an intersection and
    any intersections connected to it. A black or white
    region is called a STRING.

    3.2 Surrounded

    An intersection of one colour is SURROUNDED by another
    colour if each leaving path reaches the other colour first
    after the one colour. Hereby it can only be surrounded
    black by white, white by black, empty by black, or empty
    by white. A region can be surrounded. For strings there is
    an alternative notion of no liberty (or breath). A LIBERTY
    of a string is an empty intersection adjacent to it. Thus
    a string is surrounded if and only if it has no liberty.

    3.3 Removal, Suicide

    A removal empties the intersections of surrounded stones
    if there are any. Hereby removal of opposing stones is
    executed first, if necessary. Rules may either require or
    forbid removal of own stones. This is called suicide or no
    suicide. In practice, suicide might be used for so called ko
    fights or in capturing races.

    3.4 Capture, Prisoner

    Rules that score territory call a removal a capture
    because all removed stones are seriously kept as prisoners.

    3.5 Move, Play, Pass

    The players have alternate turns. On each turn a player makes
    a move that is either a play or a pass. A play places one's
    own stone on an empty intersection. It can then include
    removal of surrounded stones, if any. A pass merely continues
    alternation by giving the opponent the next turn.

    3.6 Compensation

    The first move advantage by black can be compensated by
    compensation points (komi) that are added to the white score
    after the game end. Komi can be adjusted by 0.5 to avoid
    ties. Today integer values for komi for 19x19 boards
    typically range between 5 and 7. For 13x13 boards one should
    use 8, for 9x9 boards 6; however, there is no real consensus
    for small board komi values yet. -
    A weaker player (black) can get the right to place an agreed
    number of compensation stones (handicap) before white's first
    play. Rules may allow free or fixed handicap. Free handicap
    does not apply any restriction. Fixed handicap requires
    traditional placement on set intersections.

    3.7 Phases

    Normally, a game consists of the phases alternation,
    agreement, scoring. A game stop is between alternation and
    agreement, the game end is between agreement and scoring,
    and after scoring both players accept the counted score as
    the result. The main part of the game is the alternation
    phase. Special rules are invoked after it. Typically, two
    successive passes in alternation are the game stop and start
    the agreement phase. In it the players may agree on strings
    to be removed. If they agree, then they remove those strings
    from the board; this ends the game. Sometimes they might
    disagree, then no strings are removed but alternation is
    resumed as if the last game stop did not occur.

    3.8 Recreation

    The position is the pattern of black and white stones on the
    board. Without extra rule a position might be repeated
    infinitely. The easiest rule to prohibit this says: A play
    may not recreate a position. This refers to positions after
    completion of plays, i.e. after possible removals. The rule
    is called "superko". -
    Some rules use concepts different from superko. They combine
    a "2-play rule" with a "long cycle rule". The first says:
    Two successive plays may not recreate a position. The second
    says: If a position is recreated after more than two moves,
    then the game ends either immediately or, as a variant, as
    soon as the players agree, with the result "without result".
    In practice the 2-play rule is sufficient for almost all
    cases. It handles the relevant standard pattern of two
    adjacent intersections. For superko this is just a special
    application.

    3.9 Scoring

    The score is the result after the game end as defined by
    the rules. There are two different scoring methods: area
    scoring and territory scoring. Rules use one of them. Both
    give the same result in almost all cases and both evaluate
    the difference of the black and the white scores. A player's
    AREA score is the sum of intersections with own stones and
    of empty intersections surrounded only by own stones. Simply
    speaking, a player's TERRITORY score is the sum of empty
    intersections surrounded only by own stones and of prisoners
    of opposing colour. With both scoring methods empty
    intersections that are not surrounded by either black or
    white are neutral.

    3.10 Counting

    A score must be determined by some mechanical procedure in
    practice; this is called counting. There are various methods.
    Some rules prescribe one. A possible method is to use one's
    finger to count point by point. Other methods rearrange a lot
    of stones on the board.

    4 PARTICULAR RULES

    Rules vary extremely. However, in practice they often give
    the same result.

    4.1 Short Rules

    Examples of short rules are the Simple Rules or the
    Tromp-Taylor rules. They have no game stop and no agreement.
    Both are superfluous since necessary removals may already be
    performed in the alternation. Two successive passes end the
    game that is scored then. Short rules use area scoring,
    superko, and suicide. Further settings are left for
    tournament rules.

    4.2 American Rules

    These are used by the American Go Association. They use
    situational superko, no suicide, and 7.5 komi. They permit
    free or fixed handicap. Their most remarkable feature is to
    allow one of area scoring or territory scoring. Herefore
    pass stones (one prisoner compensates each pass) and white
    moving last always ensure the same result, regardless of the
    applied scoring method.

    4.3 Chinese Rules

    These are used in continental China and sometimes in other
    countries. Area scoring and no suicide are used.

    4.3.1 Official Chinese Rules

    In practice, ko rules roughly amount to a 2-play rule and a
    long cycle rule. The mentioned superko is overridden. The
    counting is a sophisticated half counting, where empty
    intersections and then after rearrangements stones of one
    colour are added to be compared with half the non-neutral
    intersections. The komi as a half komi is 3.75. In full
    counting, counts and komi would be twice as big.

    4.3.2 Simplified Chinese Rules

    Positional superko is used. A counting method is not
    prescribed. The full komi should be 7.5.

    4.4 Japanese Rules

    The differences mainly affect handling of late game phases
    but often do not alter scores. Japanese rules use some
    traditional territory scoring that attempts to exclude so
    called sekis. No suicide applies. The core of the ko rules
    is a 2-play rule and a long cycle rule. Typically, komi is
    6.5. Fixed handicap should be used. The counting is a
    sophisticated rearrangement of empty intersections and
    filling-in of prisoners.

    4.4.1 Game Finishing Process

    A game finishes with the following process: 1) So called
    dame (neutral points) and defensive moves (necessary
    connections etc. due to occupied dame) are filled.
    2) The hypothetical analysis, which presumes perfect play,
    determines so called life or death of each string and the
    scoring intersections. 3) Without making any approach moves,
    dead stones are removed from scoring intersections and added
    to the prisoners. 4) The score is counted. (2) and (3) do not
    allow to play out life and death since actually filling
    intersections costs points in Japanese rules.

    4.4.2 Official Japanese Rules

    There are the Japanese 1989 Rules, which are used in Japan
    and elsewhere, and the World Amateur Go Championships Rules,
    which are used in some particular tournaments. Korean rules
    are similar to Japanese rules but have a very different text
    and differ in rare positions. Official Japanese rules are
    very incomplete and have messy late game phases. E.g., the
    Japanese 1989 Rules allow filling of dame during alternation,
    after it, or both and have a so called ko-pass-rule for the
    hypothetical analysis. Now professional Japanese rules are
    explained precisely by a rules expert's interpretation called
    "the Japanese 2003 Rules".

    4.4.3 Simplified Japanese Rules

    As a recent invention, they are not used yet. They are
    complete and have clear late game phases. Filling of dame is
    done during alternation.

    4.4.4 Verbal Japanese Rules

    They are used for informal games in many countries and
    undefined, except that the game finishing process is used.
    In a tournament without any official rules of play, disputes
    are not solved due to the rules but with a referee.

    4.5 Ing Rules

    Ing rules use area scoring, suicide, 8 komi with black
    winning ties, and free handicap.

    4.5.1 Official Ing Rules

    The ko rules are a mess but somehow resemble superko.
    Details could fill books. The late game phases are specified
    insufficiently. The peculiar counting method requires 180
    stones of each colour throughout the game, fills any stones
    on the board after the game end, and leaves exactly one
    empty intersection, which determines the winner. The
    official rules are used in professional Taiwanese and some
    sponsored tournaments. Taiwanese amateurs have their own
    rules.

    4.5.2 Simplified Ing Rules

    Positional superko is used. A counting method is not
    prescribed. The late game phases are specified clearly. The
    simplified rules are used in EGF tournaments that are said
    to use Ing rules.

    4.6 New Zealand Rules

    Area scoring, suicide, situational superko, 7 komi, and free
    handicap are used.

    4.7 Go Server Rules

    Every go server has its own and often complicated rules, if
    any, so they cannot be given in detail here. Concerning
    "IGS rules", territory scoring, no suicide, a 2-play rule,
    fixed handicap, three game stopping passes, and captures in
    an agreement phase are used. Details about agreements and
    long cycles are not specified and lead to adjourned games in
    case of doubt. Komi is suggested but may be altered. Counting
    is automatic. "Yahoo" has territory scoring, no suicide, a
    2-play rule, two game stopping passes; long cycles and
    disagreements are not handled properly. On "email servers"
    players must agree on any rules. -
    Typically territory scoring on a go server means that neither
    points in any sekis are excluded nor pass stones are used.
    Thus while the Japanese seki exception is abandoned,
    disagreements about removals may lead to games without result
    since playing out can cost points.

    4.8 International Rules

    The international mailing list go-rules has proposed
    international rules, however, none are adopted yet. The core
    rules of play shall be clear, complete, and correct.
    Currently alternative texts are offered for suicide,
    recreation, and scoring. Especially unification of scoring
    methods is advocated.

    4.9 EGF Rules

    The EGF uses the Simplified Ing Rules with 8 komi (black
    wins ties) in Ing sponsored tournaments and the Nihon Kiin
    1989 Rules with 6.5 komi in Japanese/Korean sponsored
    tournaments. If significantly the European Go Championship
    has both kinds of sponsors, then boards 1-16 use the Nihon
    Kiin 1989 Rules and boards 17+ the Simplified Ing Rules.
    However, time settings depend on ranks.

    5 TROUBLESOME DETAILS

    5.1 Colour Choice

    In even games typically the colours are randomly chosen. In
    handicap games black receives the handicap stones. -
    A manual method for randomly choosing colours is called
    nigiri. The older player hides a number of white stones
    taken from the bowl, the opponent takes one or two black
    stones to guess the parity, and the parity of the number of
    white stones is revealed. If the opponent guesses right,
    then he takes black, else he takes white.

    5.2 Pass Stones

    Some rules use pass stones. A passing player adds one own
    stone to the prisoners. As a consequence, captures before
    the game end can be resolved in alternation without any loss
    because any not answered approach move is compensated by one
    pass stone. With traditional territory scoring that uses no
    pass stones definition problems arise due to this missing
    option. Modern territory scoring or equivalence scoring use
    pass stones.

    5.3 Equivalence

    Area scoring and territory scoring are close because either
    intersections occupied by own stones or opposing prisoners
    are used. Essentially, every prisoner is a stone removed
    from some intersection. For area it scores one point less
    for the stone's player while for territory it scores one
    point more for his opponent. This is equal. Exact equality
    for the entire game must also consider passes by using pass
    stones and an equal number of moves by requiring white to
    pass last. This is done by equivalence scoring.

    5.4 Meaning of Agreement Removals

    Removals in an agreement phase under area scoring are fair
    because they may as well occur in alternation. Removing a
    stone due to agreement includes its then empty intersection
    and all adjacent empty intersections in the score. Removing
    a stone by means of alternation includes its then empty
    intersection and all adjacent newly occupied intersections
    in the score. -
    With traditional territory scoring this is not possible
    since stones on the board do not score. Thus final captures
    must occur after the game end due to attempted definitions
    in the rules.

    5.5 Practical Scoring Differences

    Since area scoring and modern territory scoring using pass
    stones are equal, correct play is the same for both. Apart
    from Japanese rules exceptions like not scoring empty
    intersections especially in asymmetrical coexistences or
    like a pass-for-ko-rule, traditional territory scoring can
    make a different winner in practically ca. every 10000th
    even game. This is so rare because of a parity feature
    combined with a scarcely odd number of intersections that
    are in coexistences but do not score for area at the game
    end. With area scoring a komi change from 1.5, 3.5, 5.5, ...
    to 2.5, 4.5, 6.5, ... almost always would not change the
    winner. So altough occupying the last empty intersections
    that would otherwise not score just before a game stop gains
    one point each, alternately doing so leaves a total
    advantage of at most one point. Due to the parity feature
    the player to get it is predetermined when this occupation
    starts. More importantly, one final ko is worth 1 point under
    traditional territory scoring but 2 or rarely 4 points under
    area scoring. Rare one-sided points in coexistences provide
    only area. Other practical differences are even rarer. Cute
    players include the stones in their endgame value counts
    during the middle of an area scoring game.

    5.6 Stone Scoring

    In ancient times stone scoring was popular. Only stones on
    the board are scored. Thus empty intersections surrounded by
    own stones are filled until necessary so called eyes remain.
    Disconnected stones require more eyes in total, the so
    called group tax.

    5.7 Old Ing Scoring

    Old Ing rules allowed fractional scores by assigning points
    to neutral empty regions due to the percentage of black and
    white stones surrounding every region.

    5.8 Primitive Rules

    They do not have passes. Alternation ends when a player
    loses due to no legal play. Games can be extremely long and
    include special strategies, so called pass fights. Primitive
    rules (also called no pass rules or Conway rules) can be
    useful in mathematics.

    5.9 Tradition

    Historically, exceptions arose, which some like as such
    especially together with Japanese style rules. So called
    sekis are excluded from the score. Special positions, termed
    precedents, have special rules. Modern Japanese rules have
    generalized a lot of them by a pass-for-ko-rule. After the
    game stop or after the game end and particularly in
    hypothetical play a stone captured in a possible 2-play cycle
    may not be recaptured unless before a pass is made that
    specifies the particular 2-play cycle.

    5.10 Positional / Situational Superko

    Positional superko prohibits a play that recreates a position.
    Situational superko refers to the situation, i.e. to the
    position together with the right to move. So a play is
    prohibited if it recreates a position while the same player
    has the right to move. In practice the differences are
    extremely rare.

    5.11 Handicap Recompensation

    With area scoring handicap stones beyond the first provide
    a potential extra area of one point per handicap stone. Komi
    for white may consider this. Recompensation, H-1 points for H
    handicap stones, is virtually only used together with
    American rules.

    5.12 Mathematics

    Go is a complete information game, i.e. at every move each
    player knows the entire game situation. Hence theoretically
    an algorithm could determine perfect play. However, due to
    the complexity of the game with N intersections, for which
    it is provably impossible to devise a polynomial time
    solution, perfect play or ideal komi are unknown. What one
    does know is that in a game without komi the first player wins
    or ties and that perfect play is independent of set komi. Many
    other propositions have been discovered, some of which
    describe the relation between area and territory scoring, solve
    tiny endgame positions or cyclical behaviour. -
    Go is a very complex game! According to John Tromp, the number
    of legal positions is:

    208168199381979984699478633344862770286522453884530548425 639456820927419612738015378525648451698519643907259916015 628128546089888314427129715319317557736620397247064840935

    For positional superko, no passes, and no resignation, the
    number of possible games is smaller than N**L(N) because L(N)
    also restricts the maximal number of moves per game and there
    are at most N possible intersections per move. (The sign ** is
    a text file notation for "to the power".) -
    Extremely modest estimates look like 10**N, which is based on
    an assumption of 10 reasonable intersections per move. A
    popular estimate for 19x19 go is 10**761, which must have
    originated from a typo and should be 10**361, if at all...
    These types of estimates are so popular because humans cannot
    even imagine the suggested number of atoms in the universe,
    10**80. For comparison, 3**361 is ca. 10**172.

    6 TOURNAMENT RULES

    6.1 Special Game Ends

    If the score considering the komi is zero, then the game is a
    tie and should be treated as 0.5 won games for each. Special
    rules or undue behaviour like sincere lateness might result
    in a referee declaring a win by forfeit, 0:0, or 1:1,
    whichever is most appropriate.

    6.2 Tournament Systems

    A tournament might consist of several stages, of which each
    has a seed and a system. A seed appropriately restricts
    participation, e.g. due to qualification. The most important
    systems are match, league, knockout, Swiss, McMahon. There
    are many others and hybrids. A system must fit the aims of a
    tournament. A sufficient number of rounds, a proper seed,
    and colour variation ensure a fair determination of the best
    player. -
    A match takes place between two players that either play a
    set number of games to see who wins more or a maximal number
    of games to see who wins a predetermined number of games
    first. In a league a small, usually even number of players
    performs a round-robin tournament, so that in each round all
    players play and every two players play against each other,
    one game e.g. A knockout preferably starts with a number of
    players that is a power of two. Losing players are eliminated,
    winning players continue until the winner remains. -
    In a Swiss system before each round each player's achieved
    number of wins is used to pair players with equal numbers as
    far as possible. So all players play all rounds and some time
    the best player will emerge. However, with greatly varying
    strengths too many rounds would be needed. So Swiss is only
    useful for particular events or handicap tournaments.
    McMahon is the refinement of Swiss. Before the start of the
    tournament all players are classified in rank groups, with
    ranks R from 0 to T. This means that one assumes a preceding
    Swiss tournament where every player has already won R games.
    Then in the McMahon tournament the strongest players, who
    deserve the rank T, compete for the top places. In practice,
    one uses a bar B, that is 1 or 2 ranks below T, so that all
    ranks above B are contracted to B and also players slightly
    weaker than the top players get their chance. All players in
    a McMahon play roughly equal opponents; if they win or lose,
    then the opponents will be stronger or weaker.

    6.3 Tie Breakers

    Tie breakers can refine pairings or results. Typically the
    first criterion is the number of wins (or McMahon points);
    all further criteria, if any, are tie breakers. They attempt
    a refinement where a low number of rounds and a tournament
    system do not guarantee sufficient distinction between
    players' achievements. However, they must be applied with
    care since they are only marginally better than coin tossing.
    Examples of tie breakers are direct comparison, which
    acknowledges the winner of a game between two players in
    question, and SOS, which is the Sum of Opponents' Scores. -
    The possible degree of quality of tie breakers is subject to
    discussion. It depends on tournament system, whether only the
    top or all players shall be distinguished, and other factors.
    An alternative to the usage of tie breakers for the final
    results ordering is issuing shared places for all players
    with the same number of wins (or McMahon points). - One must
    fairly assign tie breaker points for opponents missing in
    some round; enforcing participation is preferable especially
    for top players.

    6.4 Pairing

    Pairings must be fair, precise, and consider prior
    achievements during a tournament. One should consider colour
    balance and no pair twice, one might also aim at avoiding a
    pair of players from the same club or country, depending on
    a tournament's intentions. Pairings might be done manually
    in small tournaments; for most tournaments pairing programs
    should be used. These can create fair pairings convincingly,
    some even watch global balance.

    6.5 Thinking Times

    The age of killing each other by greater endurance has gone.
    Clocks are used to count each player's remaining thinking
    time. Typically, every game has a basic time and overtime
    periods. Exceeding a time limit loses a game. Basic time
    might be 9 hours for a professional top game, 10 minutes for
    a lightning game, or something in between that fits a
    tournament's intentions. An overtime period requires a fixed
    number of moves within a predetermined period, e.g. 1 move
    within 60 seconds. A move is finished by pressing the clock.
    - Many variants or other time systems exist, e.g., increasing
    numbers of moves in further overtime periods, penalty points
    for entering further periods, full usage of every overtime
    period, thinking time working like an hour glass, etc.

    6.6 Tournament Rules

    Every tournament uses an announced set of tournament rules.
    They especially specify the used set for the core rules of
    play, the tournament system, tie breakers, the pairing
    method, the winning criteria, compensation methods,
    thinking times, direction, jurisdiction, adjournment
    methods, penalities for being late, etc. Tournament rules
    often deal with details. Not everything can be predicted, so
    a sportsmanlike spirit is mentioned. Finally, it should be
    clear which of several rule sets takes precedence.

    6.7 Tournament Organization

    A regional tournament can be organized by a club. Big events
    can be held at the request of an association or federation,
    who also supervise. A tournament organization is responsible
    for providing a venue and playing material. It must be
    distinguished from the tournament director and his assistant
    directors, who perform the particular tasks of pairing,
    collecting results, and ensuring smooth running. Shared
    power furthermore demands independent referees.

    6.8 Jurisdiction

    Before the start of a tournament valid instances of a
    jurisdiction as well as the persons to be referees must be
    clear. Typically, for a tournament itself there is one
    referee as the first instance and a body of three referees
    as the second instance. For very peculiar cases a federation
    could have a third and final instance. Some tournament rules
    replace the second instance by a single person, called chief
    referee; to avoid confusion he ought not to judge as the
    first instance. Players should respect the referees' tough
    job of mediation or decision; referees should seriously
    enforce the rules.

    6.9 Prizes

    The first places of a tournament invoke major prizes. E.g.
    the first, second, third places might get 3/6, 2/6, 1/6 of
    the available money. In a tournament with many weaker
    players it is a good idea to provide some prizes for all
    other players that win most rounds as well. While prizes can
    be money, books, trophies, etc., one should remember that
    money is most universally accepted and trophies serve the
    media better than the winners. -
    On a related topic, a side event lottery must give equal
    chances to all participants. This is only achieved by using
    one lot for each.

    7 Links

    Most rules information, links, short rules: http://home.snafu.de/jasiek/rules.html

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Robert Jasiek@21:1/5 to All on Fri Jul 12 00:16:26 2019
    Title: Rules FAQ
    Author: Robert Jasiek <jasiek@snafu.de>
    Frequency: monthly
    Last Update: 2017-10-13; First Day: 1999-04-12
    Distribution: rec.games.go
    Copyright: free non-commercial usage for promotion

    0 CONTENTS

    1 Purpose of this Paper
    2 Information for Beginners
    3 Important Concepts
    4 Particular Rules
    5 Troublesome Details
    6 Tournament Rules
    7 Links

    1 PURPOSE OF THIS PAPER

    This paper is a basic reference for important rules terms,
    rules, and tournament rules. Beginners should read
    especially Chapters 2 and 3, players Chapters 3 to 5,
    tournament players and organizers Chapter 6.

    2 INFORMATION FOR BEGINNERS
    2.1 What Must I Know as a Beginner?

    The game is played on a grid board. Typically it has 19x19
    intersections, but 9x9 are also fine. Two players compete.
    The first player uses black stones, the other white.

    The players alternate. A player may play or pass. Playing
    is putting one's own stone on an empty intersection and
    removing any surrounded opposing stones. To avoid
    cycles, a play may not recreate any prior configuration of
    all stones on the board.

    Two successive passes end the game. Then the player with
    more intersections wins. Intersections are his if only his
    stones occupy or surround them.

    2.2 Which Rules do I Need as a Beginner?

    You can play with short rules as in 2.1. Other rules may
    be different, but the game is the same, i. e. strategy,
    tactics, and the score do not change. Extremely rare
    exceptions confirm this rule.

    The winner can be determined by area or by territory.
    Either includes empty intersections surrounded only by own
    stones. While area adds intersections occupied by own
    stones, territory adds opposing prisoners instead.

    All rules, except short rules, have further phases after
    alternation and before scoring. Towards a game end it is
    often clear which stones will be removed. The additional
    phases allow the players to agree on which stones shall be
    removed. Thereby final removals do not require alternation.

    Whether you score by area or by territory or whether you
    remove by alternation or by agreement should mainly depend
    on which rules are used by people you play with.

    2.3 Which Rules Should I Teach?

    One possibility is to use a board with 9x9 intersections,
    short rules as in 2.1, and count each player's score by
    using a finger to scan the board for his intersections.

    3 IMPORTANT CONCEPTS

    While strategy and tactics virtually remain the same,
    concepts vary in different rules. However, the following
    gives a comprehensive overview on standard terms.

    3.1 Stone, String

    The physical device that colours one intersection in a
    play is a STONE. Two intersections of the board are
    ADJACENT if they have a line but no intersection between
    them. Two intersections with either black, white, or no
    stones on them are CONNECTED if they are adjacent or if
    there is a chain of adjacent intersections of their type
    between them. A REGION consists of an intersection and
    any intersections connected to it. A black or white
    region is called a STRING.

    3.2 Surrounded

    An intersection of one colour is SURROUNDED by another
    colour if each leaving path reaches the other colour first
    after the one colour. Hereby it can only be surrounded
    black by white, white by black, empty by black, or empty
    by white. A region can be surrounded. For strings there is
    an alternative notion of no liberty (or breath). A LIBERTY
    of a string is an empty intersection adjacent to it. Thus
    a string is surrounded if and only if it has no liberty.

    3.3 Removal, Suicide

    A removal empties the intersections of surrounded stones
    if there are any. Hereby removal of opposing stones is
    executed first, if necessary. Rules may either require or
    forbid removal of own stones. This is called suicide or no
    suicide. In practice, suicide might be used for so called ko
    fights or in capturing races.

    3.4 Capture, Prisoner

    Rules that score territory call a removal a capture
    because all removed stones are seriously kept as prisoners.

    3.5 Move, Play, Pass

    The players have alternate turns. On each turn a player makes
    a move that is either a play or a pass. A play places one's
    own stone on an empty intersection. It can then include
    removal of surrounded stones, if any. A pass merely continues
    alternation by giving the opponent the next turn.

    3.6 Compensation

    The first move advantage by black can be compensated by
    compensation points (komi) that are added to the white score
    after the game end. Komi can be adjusted by 0.5 to avoid
    ties. Today integer values for komi for 19x19 boards
    typically range between 5 and 7. For 13x13 boards one should
    use 8, for 9x9 boards 6; however, there is no real consensus
    for small board komi values yet. -
    A weaker player (black) can get the right to place an agreed
    number of compensation stones (handicap) before white's first
    play. Rules may allow free or fixed handicap. Free handicap
    does not apply any restriction. Fixed handicap requires
    traditional placement on set intersections.

    3.7 Phases

    Normally, a game consists of the phases alternation,
    agreement, scoring. A game stop is between alternation and
    agreement, the game end is between agreement and scoring,
    and after scoring both players accept the counted score as
    the result. The main part of the game is the alternation
    phase. Special rules are invoked after it. Typically, two
    successive passes in alternation are the game stop and start
    the agreement phase. In it the players may agree on strings
    to be removed. If they agree, then they remove those strings
    from the board; this ends the game. Sometimes they might
    disagree, then no strings are removed but alternation is
    resumed as if the last game stop did not occur.

    3.8 Recreation

    The position is the pattern of black and white stones on the
    board. Without extra rule a position might be repeated
    infinitely. The easiest rule to prohibit this says: A play
    may not recreate a position. This refers to positions after
    completion of plays, i.e. after possible removals. The rule
    is called "superko". -
    Some rules use concepts different from superko. They combine
    a "2-play rule" with a "long cycle rule". The first says:
    Two successive plays may not recreate a position. The second
    says: If a position is recreated after more than two moves,
    then the game ends either immediately or, as a variant, as
    soon as the players agree, with the result "without result".
    In practice the 2-play rule is sufficient for almost all
    cases. It handles the relevant standard pattern of two
    adjacent intersections. For superko this is just a special
    application.

    3.9 Scoring

    The score is the result after the game end as defined by
    the rules. There are two different scoring methods: area
    scoring and territory scoring. Rules use one of them. Both
    give the same result in almost all cases and both evaluate
    the difference of the black and the white scores. A player's
    AREA score is the sum of intersections with own stones and
    of empty intersections surrounded only by own stones. Simply
    speaking, a player's TERRITORY score is the sum of empty
    intersections surrounded only by own stones and of prisoners
    of opposing colour. With both scoring methods empty
    intersections that are not surrounded by either black or
    white are neutral.

    3.10 Counting

    A score must be determined by some mechanical procedure in
    practice; this is called counting. There are various methods.
    Some rules prescribe one. A possible method is to use one's
    finger to count point by point. Other methods rearrange a lot
    of stones on the board.

    4 PARTICULAR RULES

    Rules vary extremely. However, in practice they often give
    the same result.

    4.1 Short Rules

    Examples of short rules are the Simple Rules or the
    Tromp-Taylor rules. They have no game stop and no agreement.
    Both are superfluous since necessary removals may already be
    performed in the alternation. Two successive passes end the
    game that is scored then. Short rules use area scoring,
    superko, and suicide. Further settings are left for
    tournament rules.

    4.2 American Rules

    These are used by the American Go Association. They use
    situational superko, no suicide, and 7.5 komi. They permit
    free or fixed handicap. Their most remarkable feature is to
    allow one of area scoring or territory scoring. Herefore
    pass stones (one prisoner compensates each pass) and white
    moving last always ensure the same result, regardless of the
    applied scoring method.

    4.3 Chinese Rules

    These are used in continental China and sometimes in other
    countries. Area scoring and no suicide are used.

    4.3.1 Official Chinese Rules

    In practice, ko rules roughly amount to a 2-play rule and a
    long cycle rule. The mentioned superko is overridden. The
    counting is a sophisticated half counting, where empty
    intersections and then after rearrangements stones of one
    colour are added to be compared with half the non-neutral
    intersections. The komi as a half komi is 3.75. In full
    counting, counts and komi would be twice as big.

    4.3.2 Simplified Chinese Rules

    Positional superko is used. A counting method is not
    prescribed. The full komi should be 7.5.

    4.4 Japanese Rules

    The differences mainly affect handling of late game phases
    but often do not alter scores. Japanese rules use some
    traditional territory scoring that attempts to exclude so
    called sekis. No suicide applies. The core of the ko rules
    is a 2-play rule and a long cycle rule. Typically, komi is
    6.5. Fixed handicap should be used. The counting is a
    sophisticated rearrangement of empty intersections and
    filling-in of prisoners.

    4.4.1 Game Finishing Process

    A game finishes with the following process: 1) So called
    dame (neutral points) and defensive moves (necessary
    connections etc. due to occupied dame) are filled.
    2) The hypothetical analysis, which presumes perfect play,
    determines so called life or death of each string and the
    scoring intersections. 3) Without making any approach moves,
    dead stones are removed from scoring intersections and added
    to the prisoners. 4) The score is counted. (2) and (3) do not
    allow to play out life and death since actually filling
    intersections costs points in Japanese rules.

    4.4.2 Official Japanese Rules

    There are the Japanese 1989 Rules, which are used in Japan
    and elsewhere, and the World Amateur Go Championships Rules,
    which are used in some particular tournaments. Korean rules
    are similar to Japanese rules but have a very different text
    and differ in rare positions. Official Japanese rules are
    very incomplete and have messy late game phases. E.g., the
    Japanese 1989 Rules allow filling of dame during alternation,
    after it, or both and have a so called ko-pass-rule for the
    hypothetical analysis. Now professional Japanese rules are
    explained precisely by a rules expert's interpretation called
    "the Japanese 2003 Rules".

    4.4.3 Simplified Japanese Rules

    As a recent invention, they are not used yet. They are
    complete and have clear late game phases. Filling of dame is
    done during alternation.

    4.4.4 Verbal Japanese Rules

    They are used for informal games in many countries and
    undefined, except that the game finishing process is used.
    In a tournament without any official rules of play, disputes
    are not solved due to the rules but with a referee.

    4.5 Ing Rules

    Ing rules use area scoring, suicide, 8 komi with black
    winning ties, and free handicap.

    4.5.1 Official Ing Rules

    The ko rules are a mess but somehow resemble superko.
    Details could fill books. The late game phases are specified
    insufficiently. The peculiar counting method requires 180
    stones of each colour throughout the game, fills any stones
    on the board after the game end, and leaves exactly one
    empty intersection, which determines the winner. The
    official rules are used in professional Taiwanese and some
    sponsored tournaments. Taiwanese amateurs have their own
    rules.

    4.5.2 Simplified Ing Rules

    Positional superko is used. A counting method is not
    prescribed. The late game phases are specified clearly. The
    simplified rules are used in EGF tournaments that are said
    to use Ing rules.

    4.6 New Zealand Rules

    Area scoring, suicide, situational superko, 7 komi, and free
    handicap are used.

    4.7 Go Server Rules

    Every go server has its own and often complicated rules, if
    any, so they cannot be given in detail here. Concerning
    "IGS rules", territory scoring, no suicide, a 2-play rule,
    fixed handicap, three game stopping passes, and captures in
    an agreement phase are used. Details about agreements and
    long cycles are not specified and lead to adjourned games in
    case of doubt. Komi is suggested but may be altered. Counting
    is automatic. "Yahoo" has territory scoring, no suicide, a
    2-play rule, two game stopping passes; long cycles and
    disagreements are not handled properly. On "email servers"
    players must agree on any rules. -
    Typically territory scoring on a go server means that neither
    points in any sekis are excluded nor pass stones are used.
    Thus while the Japanese seki exception is abandoned,
    disagreements about removals may lead to games without result
    since playing out can cost points.

    4.8 International Rules

    The international mailing list go-rules has proposed
    international rules, however, none are adopted yet. The core
    rules of play shall be clear, complete, and correct.
    Currently alternative texts are offered for suicide,
    recreation, and scoring. Especially unification of scoring
    methods is advocated.

    4.9 EGF Rules

    The EGF uses the Simplified Ing Rules with 8 komi (black
    wins ties) in Ing sponsored tournaments and the Nihon Kiin
    1989 Rules with 6.5 komi in Japanese/Korean sponsored
    tournaments. If significantly the European Go Championship
    has both kinds of sponsors, then boards 1-16 use the Nihon
    Kiin 1989 Rules and boards 17+ the Simplified Ing Rules.
    However, time settings depend on ranks.

    5 TROUBLESOME DETAILS

    5.1 Colour Choice

    In even games typically the colours are randomly chosen. In
    handicap games black receives the handicap stones. -
    A manual method for randomly choosing colours is called
    nigiri. The older player hides a number of white stones
    taken from the bowl, the opponent takes one or two black
    stones to guess the parity, and the parity of the number of
    white stones is revealed. If the opponent guesses right,
    then he takes black, else he takes white.

    5.2 Pass Stones

    Some rules use pass stones. A passing player adds one own
    stone to the prisoners. As a consequence, captures before
    the game end can be resolved in alternation without any loss
    because any not answered approach move is compensated by one
    pass stone. With traditional territory scoring that uses no
    pass stones definition problems arise due to this missing
    option. Modern territory scoring or equivalence scoring use
    pass stones.

    5.3 Equivalence

    Area scoring and territory scoring are close because either
    intersections occupied by own stones or opposing prisoners
    are used. Essentially, every prisoner is a stone removed
    from some intersection. For area it scores one point less
    for the stone's player while for territory it scores one
    point more for his opponent. This is equal. Exact equality
    for the entire game must also consider passes by using pass
    stones and an equal number of moves by requiring white to
    pass last. This is done by equivalence scoring.

    5.4 Meaning of Agreement Removals

    Removals in an agreement phase under area scoring are fair
    because they may as well occur in alternation. Removing a
    stone due to agreement includes its then empty intersection
    and all adjacent empty intersections in the score. Removing
    a stone by means of alternation includes its then empty
    intersection and all adjacent newly occupied intersections
    in the score. -
    With traditional territory scoring this is not possible
    since stones on the board do not score. Thus final captures
    must occur after the game end due to attempted definitions
    in the rules.

    5.5 Practical Scoring Differences

    Since area scoring and modern territory scoring using pass
    stones are equal, correct play is the same for both. Apart
    from Japanese rules exceptions like not scoring empty
    intersections especially in asymmetrical coexistences or
    like a pass-for-ko-rule, traditional territory scoring can
    make a different winner in practically ca. every 10000th
    even game. This is so rare because of a parity feature
    combined with a scarcely odd number of intersections that
    are in coexistences but do not score for area at the game
    end. With area scoring a komi change from 1.5, 3.5, 5.5, ...
    to 2.5, 4.5, 6.5, ... almost always would not change the
    winner. So altough occupying the last empty intersections
    that would otherwise not score just before a game stop gains
    one point each, alternately doing so leaves a total
    advantage of at most one point. Due to the parity feature
    the player to get it is predetermined when this occupation
    starts. More importantly, one final ko is worth 1 point under
    traditional territory scoring but 2 or rarely 4 points under
    area scoring. Rare one-sided points in coexistences provide
    only area. Other practical differences are even rarer. Cute
    players include the stones in their endgame value counts
    during the middle of an area scoring game.

    5.6 Stone Scoring

    In ancient times stone scoring was popular. Only stones on
    the board are scored. Thus empty intersections surrounded by
    own stones are filled until necessary so called eyes remain.
    Disconnected stones require more eyes in total, the so
    called group tax.

    5.7 Old Ing Scoring

    Old Ing rules allowed fractional scores by assigning points
    to neutral empty regions due to the percentage of black and
    white stones surrounding every region.

    5.8 Primitive Rules

    They do not have passes. Alternation ends when a player
    loses due to no legal play. Games can be extremely long and
    include special strategies, so called pass fights. Primitive
    rules (also called no pass rules or Conway rules) can be
    useful in mathematics.

    5.9 Tradition

    Historically, exceptions arose, which some like as such
    especially together with Japanese style rules. So called
    sekis are excluded from the score. Special positions, termed
    precedents, have special rules. Modern Japanese rules have
    generalized a lot of them by a pass-for-ko-rule. After the
    game stop or after the game end and particularly in
    hypothetical play a stone captured in a possible 2-play cycle
    may not be recaptured unless before a pass is made that
    specifies the particular 2-play cycle.

    5.10 Positional / Situational Superko

    Positional superko prohibits a play that recreates a position.
    Situational superko refers to the situation, i.e. to the
    position together with the right to move. So a play is
    prohibited if it recreates a position while the same player
    has the right to move. In practice the differences are
    extremely rare.

    5.11 Handicap Recompensation

    With area scoring handicap stones beyond the first provide
    a potential extra area of one point per handicap stone. Komi
    for white may consider this. Recompensation, H-1 points for H
    handicap stones, is virtually only used together with
    American rules.

    5.12 Mathematics

    Go is a complete information game, i.e. at every move each
    player knows the entire game situation. Hence theoretically
    an algorithm could determine perfect play. However, due to
    the complexity of the game with N intersections, for which
    it is provably impossible to devise a polynomial time
    solution, perfect play or ideal komi are unknown. What one
    does know is that in a game without komi the first player wins
    or ties and that perfect play is independent of set komi. Many
    other propositions have been discovered, some of which
    describe the relation between area and territory scoring, solve
    tiny endgame positions or cyclical behaviour. -
    Go is a very complex game! According to John Tromp, the number
    of legal positions is:

    208168199381979984699478633344862770286522453884530548425 639456820927419612738015378525648451698519643907259916015 628128546089888314427129715319317557736620397247064840935

    For positional superko, no passes, and no resignation, the
    number of possible games is smaller than N**L(N) because L(N)
    also restricts the maximal number of moves per game and there
    are at most N possible intersections per move. (The sign ** is
    a text file notation for "to the power".) -
    Extremely modest estimates look like 10**N, which is based on
    an assumption of 10 reasonable intersections per move. A
    popular estimate for 19x19 go is 10**761, which must have
    originated from a typo and should be 10**361, if at all...
    These types of estimates are so popular because humans cannot
    even imagine the suggested number of atoms in the universe,
    10**80. For comparison, 3**361 is ca. 10**172.

    6 TOURNAMENT RULES

    6.1 Special Game Ends

    If the score considering the komi is zero, then the game is a
    tie and should be treated as 0.5 won games for each. Special
    rules or undue behaviour like sincere lateness might result
    in a referee declaring a win by forfeit, 0:0, or 1:1,
    whichever is most appropriate.

    6.2 Tournament Systems

    A tournament might consist of several stages, of which each
    has a seed and a system. A seed appropriately restricts
    participation, e.g. due to qualification. The most important
    systems are match, league, knockout, Swiss, McMahon. There
    are many others and hybrids. A system must fit the aims of a
    tournament. A sufficient number of rounds, a proper seed,
    and colour variation ensure a fair determination of the best
    player. -
    A match takes place between two players that either play a
    set number of games to see who wins more or a maximal number
    of games to see who wins a predetermined number of games
    first. In a league a small, usually even number of players
    performs a round-robin tournament, so that in each round all
    players play and every two players play against each other,
    one game e.g. A knockout preferably starts with a number of
    players that is a power of two. Losing players are eliminated,
    winning players continue until the winner remains. -
    In a Swiss system before each round each player's achieved
    number of wins is used to pair players with equal numbers as
    far as possible. So all players play all rounds and some time
    the best player will emerge. However, with greatly varying
    strengths too many rounds would be needed. So Swiss is only
    useful for particular events or handicap tournaments.
    McMahon is the refinement of Swiss. Before the start of the
    tournament all players are classified in rank groups, with
    ranks R from 0 to T. This means that one assumes a preceding
    Swiss tournament where every player has already won R games.
    Then in the McMahon tournament the strongest players, who
    deserve the rank T, compete for the top places. In practice,
    one uses a bar B, that is 1 or 2 ranks below T, so that all
    ranks above B are contracted to B and also players slightly
    weaker than the top players get their chance. All players in
    a McMahon play roughly equal opponents; if they win or lose,
    then the opponents will be stronger or weaker.

    6.3 Tie Breakers

    Tie breakers can refine pairings or results. Typically the
    first criterion is the number of wins (or McMahon points);
    all further criteria, if any, are tie breakers. They attempt
    a refinement where a low number of rounds and a tournament
    system do not guarantee sufficient distinction between
    players' achievements. However, they must be applied with
    care since they are only marginally better than coin tossing.
    Examples of tie breakers are direct comparison, which
    acknowledges the winner of a game between two players in
    question, and SOS, which is the Sum of Opponents' Scores. -
    The possible degree of quality of tie breakers is subject to
    discussion. It depends on tournament system, whether only the
    top or all players shall be distinguished, and other factors.
    An alternative to the usage of tie breakers for the final
    results ordering is issuing shared places for all players
    with the same number of wins (or McMahon points). - One must
    fairly assign tie breaker points for opponents missing in
    some round; enforcing participation is preferable especially
    for top players.

    6.4 Pairing

    Pairings must be fair, precise, and consider prior
    achievements during a tournament. One should consider colour
    balance and no pair twice, one might also aim at avoiding a
    pair of players from the same club or country, depending on
    a tournament's intentions. Pairings might be done manually
    in small tournaments; for most tournaments pairing programs
    should be used. These can create fair pairings convincingly,
    some even watch global balance.

    6.5 Thinking Times

    The age of killing each other by greater endurance has gone.
    Clocks are used to count each player's remaining thinking
    time. Typically, every game has a basic time and overtime
    periods. Exceeding a time limit loses a game. Basic time
    might be 9 hours for a professional top game, 10 minutes for
    a lightning game, or something in between that fits a
    tournament's intentions. An overtime period requires a fixed
    number of moves within a predetermined period, e.g. 1 move
    within 60 seconds. A move is finished by pressing the clock.
    - Many variants or other time systems exist, e.g., increasing
    numbers of moves in further overtime periods, penalty points
    for entering further periods, full usage of every overtime
    period, thinking time working like an hour glass, etc.

    6.6 Tournament Rules

    Every tournament uses an announced set of tournament rules.
    They especially specify the used set for the core rules of
    play, the tournament system, tie breakers, the pairing
    method, the winning criteria, compensation methods,
    thinking times, direction, jurisdiction, adjournment
    methods, penalities for being late, etc. Tournament rules
    often deal with details. Not everything can be predicted, so
    a sportsmanlike spirit is mentioned. Finally, it should be
    clear which of several rule sets takes precedence.

    6.7 Tournament Organization

    A regional tournament can be organized by a club. Big events
    can be held at the request of an association or federation,
    who also supervise. A tournament organization is responsible
    for providing a venue and playing material. It must be
    distinguished from the tournament director and his assistant
    directors, who perform the particular tasks of pairing,
    collecting results, and ensuring smooth running. Shared
    power furthermore demands independent referees.

    6.8 Jurisdiction

    Before the start of a tournament valid instances of a
    jurisdiction as well as the persons to be referees must be
    clear. Typically, for a tournament itself there is one
    referee as the first instance and a body of three referees
    as the second instance. For very peculiar cases a federation
    could have a third and final instance. Some tournament rules
    replace the second instance by a single person, called chief
    referee; to avoid confusion he ought not to judge as the
    first instance. Players should respect the referees' tough
    job of mediation or decision; referees should seriously
    enforce the rules.

    6.9 Prizes

    The first places of a tournament invoke major prizes. E.g.
    the first, second, third places might get 3/6, 2/6, 1/6 of
    the available money. In a tournament with many weaker
    players it is a good idea to provide some prizes for all
    other players that win most rounds as well. While prizes can
    be money, books, trophies, etc., one should remember that
    money is most universally accepted and trophies serve the
    media better than the winners. -
    On a related topic, a side event lottery must give equal
    chances to all participants. This is only achieved by using
    one lot for each.

    7 Links

    Most rules information, links, short rules: http://home.snafu.de/jasiek/rules.html

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Robert Jasiek@21:1/5 to All on Thu Sep 12 17:30:05 2019
    Title: Rules FAQ
    Author: Robert Jasiek <jasiek@snafu.de>
    Frequency: monthly
    Last Update: 2017-10-13; First Day: 1999-04-12
    Distribution: rec.games.go
    Copyright: free non-commercial usage for promotion

    0 CONTENTS

    1 Purpose of this Paper
    2 Information for Beginners
    3 Important Concepts
    4 Particular Rules
    5 Troublesome Details
    6 Tournament Rules
    7 Links

    1 PURPOSE OF THIS PAPER

    This paper is a basic reference for important rules terms,
    rules, and tournament rules. Beginners should read
    especially Chapters 2 and 3, players Chapters 3 to 5,
    tournament players and organizers Chapter 6.

    2 INFORMATION FOR BEGINNERS
    2.1 What Must I Know as a Beginner?

    The game is played on a grid board. Typically it has 19x19
    intersections, but 9x9 are also fine. Two players compete.
    The first player uses black stones, the other white.

    The players alternate. A player may play or pass. Playing
    is putting one's own stone on an empty intersection and
    removing any surrounded opposing stones. To avoid
    cycles, a play may not recreate any prior configuration of
    all stones on the board.

    Two successive passes end the game. Then the player with
    more intersections wins. Intersections are his if only his
    stones occupy or surround them.

    2.2 Which Rules do I Need as a Beginner?

    You can play with short rules as in 2.1. Other rules may
    be different, but the game is the same, i. e. strategy,
    tactics, and the score do not change. Extremely rare
    exceptions confirm this rule.

    The winner can be determined by area or by territory.
    Either includes empty intersections surrounded only by own
    stones. While area adds intersections occupied by own
    stones, territory adds opposing prisoners instead.

    All rules, except short rules, have further phases after
    alternation and before scoring. Towards a game end it is
    often clear which stones will be removed. The additional
    phases allow the players to agree on which stones shall be
    removed. Thereby final removals do not require alternation.

    Whether you score by area or by territory or whether you
    remove by alternation or by agreement should mainly depend
    on which rules are used by people you play with.

    2.3 Which Rules Should I Teach?

    One possibility is to use a board with 9x9 intersections,
    short rules as in 2.1, and count each player's score by
    using a finger to scan the board for his intersections.

    3 IMPORTANT CONCEPTS

    While strategy and tactics virtually remain the same,
    concepts vary in different rules. However, the following
    gives a comprehensive overview on standard terms.

    3.1 Stone, String

    The physical device that colours one intersection in a
    play is a STONE. Two intersections of the board are
    ADJACENT if they have a line but no intersection between
    them. Two intersections with either black, white, or no
    stones on them are CONNECTED if they are adjacent or if
    there is a chain of adjacent intersections of their type
    between them. A REGION consists of an intersection and
    any intersections connected to it. A black or white
    region is called a STRING.

    3.2 Surrounded

    An intersection of one colour is SURROUNDED by another
    colour if each leaving path reaches the other colour first
    after the one colour. Hereby it can only be surrounded
    black by white, white by black, empty by black, or empty
    by white. A region can be surrounded. For strings there is
    an alternative notion of no liberty (or breath). A LIBERTY
    of a string is an empty intersection adjacent to it. Thus
    a string is surrounded if and only if it has no liberty.

    3.3 Removal, Suicide

    A removal empties the intersections of surrounded stones
    if there are any. Hereby removal of opposing stones is
    executed first, if necessary. Rules may either require or
    forbid removal of own stones. This is called suicide or no
    suicide. In practice, suicide might be used for so called ko
    fights or in capturing races.

    3.4 Capture, Prisoner

    Rules that score territory call a removal a capture
    because all removed stones are seriously kept as prisoners.

    3.5 Move, Play, Pass

    The players have alternate turns. On each turn a player makes
    a move that is either a play or a pass. A play places one's
    own stone on an empty intersection. It can then include
    removal of surrounded stones, if any. A pass merely continues
    alternation by giving the opponent the next turn.

    3.6 Compensation

    The first move advantage by black can be compensated by
    compensation points (komi) that are added to the white score
    after the game end. Komi can be adjusted by 0.5 to avoid
    ties. Today integer values for komi for 19x19 boards
    typically range between 5 and 7. For 13x13 boards one should
    use 8, for 9x9 boards 6; however, there is no real consensus
    for small board komi values yet. -
    A weaker player (black) can get the right to place an agreed
    number of compensation stones (handicap) before white's first
    play. Rules may allow free or fixed handicap. Free handicap
    does not apply any restriction. Fixed handicap requires
    traditional placement on set intersections.

    3.7 Phases

    Normally, a game consists of the phases alternation,
    agreement, scoring. A game stop is between alternation and
    agreement, the game end is between agreement and scoring,
    and after scoring both players accept the counted score as
    the result. The main part of the game is the alternation
    phase. Special rules are invoked after it. Typically, two
    successive passes in alternation are the game stop and start
    the agreement phase. In it the players may agree on strings
    to be removed. If they agree, then they remove those strings
    from the board; this ends the game. Sometimes they might
    disagree, then no strings are removed but alternation is
    resumed as if the last game stop did not occur.

    3.8 Recreation

    The position is the pattern of black and white stones on the
    board. Without extra rule a position might be repeated
    infinitely. The easiest rule to prohibit this says: A play
    may not recreate a position. This refers to positions after
    completion of plays, i.e. after possible removals. The rule
    is called "superko". -
    Some rules use concepts different from superko. They combine
    a "2-play rule" with a "long cycle rule". The first says:
    Two successive plays may not recreate a position. The second
    says: If a position is recreated after more than two moves,
    then the game ends either immediately or, as a variant, as
    soon as the players agree, with the result "without result".
    In practice the 2-play rule is sufficient for almost all
    cases. It handles the relevant standard pattern of two
    adjacent intersections. For superko this is just a special
    application.

    3.9 Scoring

    The score is the result after the game end as defined by
    the rules. There are two different scoring methods: area
    scoring and territory scoring. Rules use one of them. Both
    give the same result in almost all cases and both evaluate
    the difference of the black and the white scores. A player's
    AREA score is the sum of intersections with own stones and
    of empty intersections surrounded only by own stones. Simply
    speaking, a player's TERRITORY score is the sum of empty
    intersections surrounded only by own stones and of prisoners
    of opposing colour. With both scoring methods empty
    intersections that are not surrounded by either black or
    white are neutral.

    3.10 Counting

    A score must be determined by some mechanical procedure in
    practice; this is called counting. There are various methods.
    Some rules prescribe one. A possible method is to use one's
    finger to count point by point. Other methods rearrange a lot
    of stones on the board.

    4 PARTICULAR RULES

    Rules vary extremely. However, in practice they often give
    the same result.

    4.1 Short Rules

    Examples of short rules are the Simple Rules or the
    Tromp-Taylor rules. They have no game stop and no agreement.
    Both are superfluous since necessary removals may already be
    performed in the alternation. Two successive passes end the
    game that is scored then. Short rules use area scoring,
    superko, and suicide. Further settings are left for
    tournament rules.

    4.2 American Rules

    These are used by the American Go Association. They use
    situational superko, no suicide, and 7.5 komi. They permit
    free or fixed handicap. Their most remarkable feature is to
    allow one of area scoring or territory scoring. Herefore
    pass stones (one prisoner compensates each pass) and white
    moving last always ensure the same result, regardless of the
    applied scoring method.

    4.3 Chinese Rules

    These are used in continental China and sometimes in other
    countries. Area scoring and no suicide are used.

    4.3.1 Official Chinese Rules

    In practice, ko rules roughly amount to a 2-play rule and a
    long cycle rule. The mentioned superko is overridden. The
    counting is a sophisticated half counting, where empty
    intersections and then after rearrangements stones of one
    colour are added to be compared with half the non-neutral
    intersections. The komi as a half komi is 3.75. In full
    counting, counts and komi would be twice as big.

    4.3.2 Simplified Chinese Rules

    Positional superko is used. A counting method is not
    prescribed. The full komi should be 7.5.

    4.4 Japanese Rules

    The differences mainly affect handling of late game phases
    but often do not alter scores. Japanese rules use some
    traditional territory scoring that attempts to exclude so
    called sekis. No suicide applies. The core of the ko rules
    is a 2-play rule and a long cycle rule. Typically, komi is
    6.5. Fixed handicap should be used. The counting is a
    sophisticated rearrangement of empty intersections and
    filling-in of prisoners.

    4.4.1 Game Finishing Process

    A game finishes with the following process: 1) So called
    dame (neutral points) and defensive moves (necessary
    connections etc. due to occupied dame) are filled.
    2) The hypothetical analysis, which presumes perfect play,
    determines so called life or death of each string and the
    scoring intersections. 3) Without making any approach moves,
    dead stones are removed from scoring intersections and added
    to the prisoners. 4) The score is counted. (2) and (3) do not
    allow to play out life and death since actually filling
    intersections costs points in Japanese rules.

    4.4.2 Official Japanese Rules

    There are the Japanese 1989 Rules, which are used in Japan
    and elsewhere, and the World Amateur Go Championships Rules,
    which are used in some particular tournaments. Korean rules
    are similar to Japanese rules but have a very different text
    and differ in rare positions. Official Japanese rules are
    very incomplete and have messy late game phases. E.g., the
    Japanese 1989 Rules allow filling of dame during alternation,
    after it, or both and have a so called ko-pass-rule for the
    hypothetical analysis. Now professional Japanese rules are
    explained precisely by a rules expert's interpretation called
    "the Japanese 2003 Rules".

    4.4.3 Simplified Japanese Rules

    As a recent invention, they are not used yet. They are
    complete and have clear late game phases. Filling of dame is
    done during alternation.

    4.4.4 Verbal Japanese Rules

    They are used for informal games in many countries and
    undefined, except that the game finishing process is used.
    In a tournament without any official rules of play, disputes
    are not solved due to the rules but with a referee.

    4.5 Ing Rules

    Ing rules use area scoring, suicide, 8 komi with black
    winning ties, and free handicap.

    4.5.1 Official Ing Rules

    The ko rules are a mess but somehow resemble superko.
    Details could fill books. The late game phases are specified
    insufficiently. The peculiar counting method requires 180
    stones of each colour throughout the game, fills any stones
    on the board after the game end, and leaves exactly one
    empty intersection, which determines the winner. The
    official rules are used in professional Taiwanese and some
    sponsored tournaments. Taiwanese amateurs have their own
    rules.

    4.5.2 Simplified Ing Rules

    Positional superko is used. A counting method is not
    prescribed. The late game phases are specified clearly. The
    simplified rules are used in EGF tournaments that are said
    to use Ing rules.

    4.6 New Zealand Rules

    Area scoring, suicide, situational superko, 7 komi, and free
    handicap are used.

    4.7 Go Server Rules

    Every go server has its own and often complicated rules, if
    any, so they cannot be given in detail here. Concerning
    "IGS rules", territory scoring, no suicide, a 2-play rule,
    fixed handicap, three game stopping passes, and captures in
    an agreement phase are used. Details about agreements and
    long cycles are not specified and lead to adjourned games in
    case of doubt. Komi is suggested but may be altered. Counting
    is automatic. "Yahoo" has territory scoring, no suicide, a
    2-play rule, two game stopping passes; long cycles and
    disagreements are not handled properly. On "email servers"
    players must agree on any rules. -
    Typically territory scoring on a go server means that neither
    points in any sekis are excluded nor pass stones are used.
    Thus while the Japanese seki exception is abandoned,
    disagreements about removals may lead to games without result
    since playing out can cost points.

    4.8 International Rules

    The international mailing list go-rules has proposed
    international rules, however, none are adopted yet. The core
    rules of play shall be clear, complete, and correct.
    Currently alternative texts are offered for suicide,
    recreation, and scoring. Especially unification of scoring
    methods is advocated.

    4.9 EGF Rules

    The EGF uses the Simplified Ing Rules with 8 komi (black
    wins ties) in Ing sponsored tournaments and the Nihon Kiin
    1989 Rules with 6.5 komi in Japanese/Korean sponsored
    tournaments. If significantly the European Go Championship
    has both kinds of sponsors, then boards 1-16 use the Nihon
    Kiin 1989 Rules and boards 17+ the Simplified Ing Rules.
    However, time settings depend on ranks.

    5 TROUBLESOME DETAILS

    5.1 Colour Choice

    In even games typically the colours are randomly chosen. In
    handicap games black receives the handicap stones. -
    A manual method for randomly choosing colours is called
    nigiri. The older player hides a number of white stones
    taken from the bowl, the opponent takes one or two black
    stones to guess the parity, and the parity of the number of
    white stones is revealed. If the opponent guesses right,
    then he takes black, else he takes white.

    5.2 Pass Stones

    Some rules use pass stones. A passing player adds one own
    stone to the prisoners. As a consequence, captures before
    the game end can be resolved in alternation without any loss
    because any not answered approach move is compensated by one
    pass stone. With traditional territory scoring that uses no
    pass stones definition problems arise due to this missing
    option. Modern territory scoring or equivalence scoring use
    pass stones.

    5.3 Equivalence

    Area scoring and territory scoring are close because either
    intersections occupied by own stones or opposing prisoners
    are used. Essentially, every prisoner is a stone removed
    from some intersection. For area it scores one point less
    for the stone's player while for territory it scores one
    point more for his opponent. This is equal. Exact equality
    for the entire game must also consider passes by using pass
    stones and an equal number of moves by requiring white to
    pass last. This is done by equivalence scoring.

    5.4 Meaning of Agreement Removals

    Removals in an agreement phase under area scoring are fair
    because they may as well occur in alternation. Removing a
    stone due to agreement includes its then empty intersection
    and all adjacent empty intersections in the score. Removing
    a stone by means of alternation includes its then empty
    intersection and all adjacent newly occupied intersections
    in the score. -
    With traditional territory scoring this is not possible
    since stones on the board do not score. Thus final captures
    must occur after the game end due to attempted definitions
    in the rules.

    5.5 Practical Scoring Differences

    Since area scoring and modern territory scoring using pass
    stones are equal, correct play is the same for both. Apart
    from Japanese rules exceptions like not scoring empty
    intersections especially in asymmetrical coexistences or
    like a pass-for-ko-rule, traditional territory scoring can
    make a different winner in practically ca. every 10000th
    even game. This is so rare because of a parity feature
    combined with a scarcely odd number of intersections that
    are in coexistences but do not score for area at the game
    end. With area scoring a komi change from 1.5, 3.5, 5.5, ...
    to 2.5, 4.5, 6.5, ... almost always would not change the
    winner. So altough occupying the last empty intersections
    that would otherwise not score just before a game stop gains
    one point each, alternately doing so leaves a total
    advantage of at most one point. Due to the parity feature
    the player to get it is predetermined when this occupation
    starts. More importantly, one final ko is worth 1 point under
    traditional territory scoring but 2 or rarely 4 points under
    area scoring. Rare one-sided points in coexistences provide
    only area. Other practical differences are even rarer. Cute
    players include the stones in their endgame value counts
    during the middle of an area scoring game.

    5.6 Stone Scoring

    In ancient times stone scoring was popular. Only stones on
    the board are scored. Thus empty intersections surrounded by
    own stones are filled until necessary so called eyes remain.
    Disconnected stones require more eyes in total, the so
    called group tax.

    5.7 Old Ing Scoring

    Old Ing rules allowed fractional scores by assigning points
    to neutral empty regions due to the percentage of black and
    white stones surrounding every region.

    5.8 Primitive Rules

    They do not have passes. Alternation ends when a player
    loses due to no legal play. Games can be extremely long and
    include special strategies, so called pass fights. Primitive
    rules (also called no pass rules or Conway rules) can be
    useful in mathematics.

    5.9 Tradition

    Historically, exceptions arose, which some like as such
    especially together with Japanese style rules. So called
    sekis are excluded from the score. Special positions, termed
    precedents, have special rules. Modern Japanese rules have
    generalized a lot of them by a pass-for-ko-rule. After the
    game stop or after the game end and particularly in
    hypothetical play a stone captured in a possible 2-play cycle
    may not be recaptured unless before a pass is made that
    specifies the particular 2-play cycle.

    5.10 Positional / Situational Superko

    Positional superko prohibits a play that recreates a position.
    Situational superko refers to the situation, i.e. to the
    position together with the right to move. So a play is
    prohibited if it recreates a position while the same player
    has the right to move. In practice the differences are
    extremely rare.

    5.11 Handicap Recompensation

    With area scoring handicap stones beyond the first provide
    a potential extra area of one point per handicap stone. Komi
    for white may consider this. Recompensation, H-1 points for H
    handicap stones, is virtually only used together with
    American rules.

    5.12 Mathematics

    Go is a complete information game, i.e. at every move each
    player knows the entire game situation. Hence theoretically
    an algorithm could determine perfect play. However, due to
    the complexity of the game with N intersections, for which
    it is provably impossible to devise a polynomial time
    solution, perfect play or ideal komi are unknown. What one
    does know is that in a game without komi the first player wins
    or ties and that perfect play is independent of set komi. Many
    other propositions have been discovered, some of which
    describe the relation between area and territory scoring, solve
    tiny endgame positions or cyclical behaviour. -
    Go is a very complex game! According to John Tromp, the number
    of legal positions is:

    208168199381979984699478633344862770286522453884530548425 639456820927419612738015378525648451698519643907259916015 628128546089888314427129715319317557736620397247064840935

    For positional superko, no passes, and no resignation, the
    number of possible games is smaller than N**L(N) because L(N)
    also restricts the maximal number of moves per game and there
    are at most N possible intersections per move. (The sign ** is
    a text file notation for "to the power".) -
    Extremely modest estimates look like 10**N, which is based on
    an assumption of 10 reasonable intersections per move. A
    popular estimate for 19x19 go is 10**761, which must have
    originated from a typo and should be 10**361, if at all...
    These types of estimates are so popular because humans cannot
    even imagine the suggested number of atoms in the universe,
    10**80. For comparison, 3**361 is ca. 10**172.

    6 TOURNAMENT RULES

    6.1 Special Game Ends

    If the score considering the komi is zero, then the game is a
    tie and should be treated as 0.5 won games for each. Special
    rules or undue behaviour like sincere lateness might result
    in a referee declaring a win by forfeit, 0:0, or 1:1,
    whichever is most appropriate.

    6.2 Tournament Systems

    A tournament might consist of several stages, of which each
    has a seed and a system. A seed appropriately restricts
    participation, e.g. due to qualification. The most important
    systems are match, league, knockout, Swiss, McMahon. There
    are many others and hybrids. A system must fit the aims of a
    tournament. A sufficient number of rounds, a proper seed,
    and colour variation ensure a fair determination of the best
    player. -
    A match takes place between two players that either play a
    set number of games to see who wins more or a maximal number
    of games to see who wins a predetermined number of games
    first. In a league a small, usually even number of players
    performs a round-robin tournament, so that in each round all
    players play and every two players play against each other,
    one game e.g. A knockout preferably starts with a number of
    players that is a power of two. Losing players are eliminated,
    winning players continue until the winner remains. -
    In a Swiss system before each round each player's achieved
    number of wins is used to pair players with equal numbers as
    far as possible. So all players play all rounds and some time
    the best player will emerge. However, with greatly varying
    strengths too many rounds would be needed. So Swiss is only
    useful for particular events or handicap tournaments.
    McMahon is the refinement of Swiss. Before the start of the
    tournament all players are classified in rank groups, with
    ranks R from 0 to T. This means that one assumes a preceding
    Swiss tournament where every player has already won R games.
    Then in the McMahon tournament the strongest players, who
    deserve the rank T, compete for the top places. In practice,
    one uses a bar B, that is 1 or 2 ranks below T, so that all
    ranks above B are contracted to B and also players slightly
    weaker than the top players get their chance. All players in
    a McMahon play roughly equal opponents; if they win or lose,
    then the opponents will be stronger or weaker.

    6.3 Tie Breakers

    Tie breakers can refine pairings or results. Typically the
    first criterion is the number of wins (or McMahon points);
    all further criteria, if any, are tie breakers. They attempt
    a refinement where a low number of rounds and a tournament
    system do not guarantee sufficient distinction between
    players' achievements. However, they must be applied with
    care since they are only marginally better than coin tossing.
    Examples of tie breakers are direct comparison, which
    acknowledges the winner of a game between two players in
    question, and SOS, which is the Sum of Opponents' Scores. -
    The possible degree of quality of tie breakers is subject to
    discussion. It depends on tournament system, whether only the
    top or all players shall be distinguished, and other factors.
    An alternative to the usage of tie breakers for the final
    results ordering is issuing shared places for all players
    with the same number of wins (or McMahon points). - One must
    fairly assign tie breaker points for opponents missing in
    some round; enforcing participation is preferable especially
    for top players.

    6.4 Pairing

    Pairings must be fair, precise, and consider prior
    achievements during a tournament. One should consider colour
    balance and no pair twice, one might also aim at avoiding a
    pair of players from the same club or country, depending on
    a tournament's intentions. Pairings might be done manually
    in small tournaments; for most tournaments pairing programs
    should be used. These can create fair pairings convincingly,
    some even watch global balance.

    6.5 Thinking Times

    The age of killing each other by greater endurance has gone.
    Clocks are used to count each player's remaining thinking
    time. Typically, every game has a basic time and overtime
    periods. Exceeding a time limit loses a game. Basic time
    might be 9 hours for a professional top game, 10 minutes for
    a lightning game, or something in between that fits a
    tournament's intentions. An overtime period requires a fixed
    number of moves within a predetermined period, e.g. 1 move
    within 60 seconds. A move is finished by pressing the clock.
    - Many variants or other time systems exist, e.g., increasing
    numbers of moves in further overtime periods, penalty points
    for entering further periods, full usage of every overtime
    period, thinking time working like an hour glass, etc.

    6.6 Tournament Rules

    Every tournament uses an announced set of tournament rules.
    They especially specify the used set for the core rules of
    play, the tournament system, tie breakers, the pairing
    method, the winning criteria, compensation methods,
    thinking times, direction, jurisdiction, adjournment
    methods, penalities for being late, etc. Tournament rules
    often deal with details. Not everything can be predicted, so
    a sportsmanlike spirit is mentioned. Finally, it should be
    clear which of several rule sets takes precedence.

    6.7 Tournament Organization

    A regional tournament can be organized by a club. Big events
    can be held at the request of an association or federation,
    who also supervise. A tournament organization is responsible
    for providing a venue and playing material. It must be
    distinguished from the tournament director and his assistant
    directors, who perform the particular tasks of pairing,
    collecting results, and ensuring smooth running. Shared
    power furthermore demands independent referees.

    6.8 Jurisdiction

    Before the start of a tournament valid instances of a
    jurisdiction as well as the persons to be referees must be
    clear. Typically, for a tournament itself there is one
    referee as the first instance and a body of three referees
    as the second instance. For very peculiar cases a federation
    could have a third and final instance. Some tournament rules
    replace the second instance by a single person, called chief
    referee; to avoid confusion he ought not to judge as the
    first instance. Players should respect the referees' tough
    job of mediation or decision; referees should seriously
    enforce the rules.

    6.9 Prizes

    The first places of a tournament invoke major prizes. E.g.
    the first, second, third places might get 3/6, 2/6, 1/6 of
    the available money. In a tournament with many weaker
    players it is a good idea to provide some prizes for all
    other players that win most rounds as well. While prizes can
    be money, books, trophies, etc., one should remember that
    money is most universally accepted and trophies serve the
    media better than the winners. -
    On a related topic, a side event lottery must give equal
    chances to all participants. This is only achieved by using
    one lot for each.

    7 Links

    Most rules information, links, short rules: http://home.snafu.de/jasiek/rules.html

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Robert Jasiek@21:1/5 to All on Sat Oct 12 15:33:04 2019
    Title: Rules FAQ
    Author: Robert Jasiek <jasiek@snafu.de>
    Frequency: monthly
    Last Update: 2017-10-13; First Day: 1999-04-12
    Distribution: rec.games.go
    Copyright: free non-commercial usage for promotion

    0 CONTENTS

    1 Purpose of this Paper
    2 Information for Beginners
    3 Important Concepts
    4 Particular Rules
    5 Troublesome Details
    6 Tournament Rules
    7 Links

    1 PURPOSE OF THIS PAPER

    This paper is a basic reference for important rules terms,
    rules, and tournament rules. Beginners should read
    especially Chapters 2 and 3, players Chapters 3 to 5,
    tournament players and organizers Chapter 6.

    2 INFORMATION FOR BEGINNERS
    2.1 What Must I Know as a Beginner?

    The game is played on a grid board. Typically it has 19x19
    intersections, but 9x9 are also fine. Two players compete.
    The first player uses black stones, the other white.

    The players alternate. A player may play or pass. Playing
    is putting one's own stone on an empty intersection and
    removing any surrounded opposing stones. To avoid
    cycles, a play may not recreate any prior configuration of
    all stones on the board.

    Two successive passes end the game. Then the player with
    more intersections wins. Intersections are his if only his
    stones occupy or surround them.

    2.2 Which Rules do I Need as a Beginner?

    You can play with short rules as in 2.1. Other rules may
    be different, but the game is the same, i. e. strategy,
    tactics, and the score do not change. Extremely rare
    exceptions confirm this rule.

    The winner can be determined by area or by territory.
    Either includes empty intersections surrounded only by own
    stones. While area adds intersections occupied by own
    stones, territory adds opposing prisoners instead.

    All rules, except short rules, have further phases after
    alternation and before scoring. Towards a game end it is
    often clear which stones will be removed. The additional
    phases allow the players to agree on which stones shall be
    removed. Thereby final removals do not require alternation.

    Whether you score by area or by territory or whether you
    remove by alternation or by agreement should mainly depend
    on which rules are used by people you play with.

    2.3 Which Rules Should I Teach?

    One possibility is to use a board with 9x9 intersections,
    short rules as in 2.1, and count each player's score by
    using a finger to scan the board for his intersections.

    3 IMPORTANT CONCEPTS

    While strategy and tactics virtually remain the same,
    concepts vary in different rules. However, the following
    gives a comprehensive overview on standard terms.

    3.1 Stone, String

    The physical device that colours one intersection in a
    play is a STONE. Two intersections of the board are
    ADJACENT if they have a line but no intersection between
    them. Two intersections with either black, white, or no
    stones on them are CONNECTED if they are adjacent or if
    there is a chain of adjacent intersections of their type
    between them. A REGION consists of an intersection and
    any intersections connected to it. A black or white
    region is called a STRING.

    3.2 Surrounded

    An intersection of one colour is SURROUNDED by another
    colour if each leaving path reaches the other colour first
    after the one colour. Hereby it can only be surrounded
    black by white, white by black, empty by black, or empty
    by white. A region can be surrounded. For strings there is
    an alternative notion of no liberty (or breath). A LIBERTY
    of a string is an empty intersection adjacent to it. Thus
    a string is surrounded if and only if it has no liberty.

    3.3 Removal, Suicide

    A removal empties the intersections of surrounded stones
    if there are any. Hereby removal of opposing stones is
    executed first, if necessary. Rules may either require or
    forbid removal of own stones. This is called suicide or no
    suicide. In practice, suicide might be used for so called ko
    fights or in capturing races.

    3.4 Capture, Prisoner

    Rules that score territory call a removal a capture
    because all removed stones are seriously kept as prisoners.

    3.5 Move, Play, Pass

    The players have alternate turns. On each turn a player makes
    a move that is either a play or a pass. A play places one's
    own stone on an empty intersection. It can then include
    removal of surrounded stones, if any. A pass merely continues
    alternation by giving the opponent the next turn.

    3.6 Compensation

    The first move advantage by black can be compensated by
    compensation points (komi) that are added to the white score
    after the game end. Komi can be adjusted by 0.5 to avoid
    ties. Today integer values for komi for 19x19 boards
    typically range between 5 and 7. For 13x13 boards one should
    use 8, for 9x9 boards 6; however, there is no real consensus
    for small board komi values yet. -
    A weaker player (black) can get the right to place an agreed
    number of compensation stones (handicap) before white's first
    play. Rules may allow free or fixed handicap. Free handicap
    does not apply any restriction. Fixed handicap requires
    traditional placement on set intersections.

    3.7 Phases

    Normally, a game consists of the phases alternation,
    agreement, scoring. A game stop is between alternation and
    agreement, the game end is between agreement and scoring,
    and after scoring both players accept the counted score as
    the result. The main part of the game is the alternation
    phase. Special rules are invoked after it. Typically, two
    successive passes in alternation are the game stop and start
    the agreement phase. In it the players may agree on strings
    to be removed. If they agree, then they remove those strings
    from the board; this ends the game. Sometimes they might
    disagree, then no strings are removed but alternation is
    resumed as if the last game stop did not occur.

    3.8 Recreation

    The position is the pattern of black and white stones on the
    board. Without extra rule a position might be repeated
    infinitely. The easiest rule to prohibit this says: A play
    may not recreate a position. This refers to positions after
    completion of plays, i.e. after possible removals. The rule
    is called "superko". -
    Some rules use concepts different from superko. They combine
    a "2-play rule" with a "long cycle rule". The first says:
    Two successive plays may not recreate a position. The second
    says: If a position is recreated after more than two moves,
    then the game ends either immediately or, as a variant, as
    soon as the players agree, with the result "without result".
    In practice the 2-play rule is sufficient for almost all
    cases. It handles the relevant standard pattern of two
    adjacent intersections. For superko this is just a special
    application.

    3.9 Scoring

    The score is the result after the game end as defined by
    the rules. There are two different scoring methods: area
    scoring and territory scoring. Rules use one of them. Both
    give the same result in almost all cases and both evaluate
    the difference of the black and the white scores. A player's
    AREA score is the sum of intersections with own stones and
    of empty intersections surrounded only by own stones. Simply
    speaking, a player's TERRITORY score is the sum of empty
    intersections surrounded only by own stones and of prisoners
    of opposing colour. With both scoring methods empty
    intersections that are not surrounded by either black or
    white are neutral.

    3.10 Counting

    A score must be determined by some mechanical procedure in
    practice; this is called counting. There are various methods.
    Some rules prescribe one. A possible method is to use one's
    finger to count point by point. Other methods rearrange a lot
    of stones on the board.

    4 PARTICULAR RULES

    Rules vary extremely. However, in practice they often give
    the same result.

    4.1 Short Rules

    Examples of short rules are the Simple Rules or the
    Tromp-Taylor rules. They have no game stop and no agreement.
    Both are superfluous since necessary removals may already be
    performed in the alternation. Two successive passes end the
    game that is scored then. Short rules use area scoring,
    superko, and suicide. Further settings are left for
    tournament rules.

    4.2 American Rules

    These are used by the American Go Association. They use
    situational superko, no suicide, and 7.5 komi. They permit
    free or fixed handicap. Their most remarkable feature is to
    allow one of area scoring or territory scoring. Herefore
    pass stones (one prisoner compensates each pass) and white
    moving last always ensure the same result, regardless of the
    applied scoring method.

    4.3 Chinese Rules

    These are used in continental China and sometimes in other
    countries. Area scoring and no suicide are used.

    4.3.1 Official Chinese Rules

    In practice, ko rules roughly amount to a 2-play rule and a
    long cycle rule. The mentioned superko is overridden. The
    counting is a sophisticated half counting, where empty
    intersections and then after rearrangements stones of one
    colour are added to be compared with half the non-neutral
    intersections. The komi as a half komi is 3.75. In full
    counting, counts and komi would be twice as big.

    4.3.2 Simplified Chinese Rules

    Positional superko is used. A counting method is not
    prescribed. The full komi should be 7.5.

    4.4 Japanese Rules

    The differences mainly affect handling of late game phases
    but often do not alter scores. Japanese rules use some
    traditional territory scoring that attempts to exclude so
    called sekis. No suicide applies. The core of the ko rules
    is a 2-play rule and a long cycle rule. Typically, komi is
    6.5. Fixed handicap should be used. The counting is a
    sophisticated rearrangement of empty intersections and
    filling-in of prisoners.

    4.4.1 Game Finishing Process

    A game finishes with the following process: 1) So called
    dame (neutral points) and defensive moves (necessary
    connections etc. due to occupied dame) are filled.
    2) The hypothetical analysis, which presumes perfect play,
    determines so called life or death of each string and the
    scoring intersections. 3) Without making any approach moves,
    dead stones are removed from scoring intersections and added
    to the prisoners. 4) The score is counted. (2) and (3) do not
    allow to play out life and death since actually filling
    intersections costs points in Japanese rules.

    4.4.2 Official Japanese Rules

    There are the Japanese 1989 Rules, which are used in Japan
    and elsewhere, and the World Amateur Go Championships Rules,
    which are used in some particular tournaments. Korean rules
    are similar to Japanese rules but have a very different text
    and differ in rare positions. Official Japanese rules are
    very incomplete and have messy late game phases. E.g., the
    Japanese 1989 Rules allow filling of dame during alternation,
    after it, or both and have a so called ko-pass-rule for the
    hypothetical analysis. Now professional Japanese rules are
    explained precisely by a rules expert's interpretation called
    "the Japanese 2003 Rules".

    4.4.3 Simplified Japanese Rules

    As a recent invention, they are not used yet. They are
    complete and have clear late game phases. Filling of dame is
    done during alternation.

    4.4.4 Verbal Japanese Rules

    They are used for informal games in many countries and
    undefined, except that the game finishing process is used.
    In a tournament without any official rules of play, disputes
    are not solved due to the rules but with a referee.

    4.5 Ing Rules

    Ing rules use area scoring, suicide, 8 komi with black
    winning ties, and free handicap.

    4.5.1 Official Ing Rules

    The ko rules are a mess but somehow resemble superko.
    Details could fill books. The late game phases are specified
    insufficiently. The peculiar counting method requires 180
    stones of each colour throughout the game, fills any stones
    on the board after the game end, and leaves exactly one
    empty intersection, which determines the winner. The
    official rules are used in professional Taiwanese and some
    sponsored tournaments. Taiwanese amateurs have their own
    rules.

    4.5.2 Simplified Ing Rules

    Positional superko is used. A counting method is not
    prescribed. The late game phases are specified clearly. The
    simplified rules are used in EGF tournaments that are said
    to use Ing rules.

    4.6 New Zealand Rules

    Area scoring, suicide, situational superko, 7 komi, and free
    handicap are used.

    4.7 Go Server Rules

    Every go server has its own and often complicated rules, if
    any, so they cannot be given in detail here. Concerning
    "IGS rules", territory scoring, no suicide, a 2-play rule,
    fixed handicap, three game stopping passes, and captures in
    an agreement phase are used. Details about agreements and
    long cycles are not specified and lead to adjourned games in
    case of doubt. Komi is suggested but may be altered. Counting
    is automatic. "Yahoo" has territory scoring, no suicide, a
    2-play rule, two game stopping passes; long cycles and
    disagreements are not handled properly. On "email servers"
    players must agree on any rules. -
    Typically territory scoring on a go server means that neither
    points in any sekis are excluded nor pass stones are used.
    Thus while the Japanese seki exception is abandoned,
    disagreements about removals may lead to games without result
    since playing out can cost points.

    4.8 International Rules

    The international mailing list go-rules has proposed
    international rules, however, none are adopted yet. The core
    rules of play shall be clear, complete, and correct.
    Currently alternative texts are offered for suicide,
    recreation, and scoring. Especially unification of scoring
    methods is advocated.

    4.9 EGF Rules

    The EGF uses the Simplified Ing Rules with 8 komi (black
    wins ties) in Ing sponsored tournaments and the Nihon Kiin
    1989 Rules with 6.5 komi in Japanese/Korean sponsored
    tournaments. If significantly the European Go Championship
    has both kinds of sponsors, then boards 1-16 use the Nihon
    Kiin 1989 Rules and boards 17+ the Simplified Ing Rules.
    However, time settings depend on ranks.

    5 TROUBLESOME DETAILS

    5.1 Colour Choice

    In even games typically the colours are randomly chosen. In
    handicap games black receives the handicap stones. -
    A manual method for randomly choosing colours is called
    nigiri. The older player hides a number of white stones
    taken from the bowl, the opponent takes one or two black
    stones to guess the parity, and the parity of the number of
    white stones is revealed. If the opponent guesses right,
    then he takes black, else he takes white.

    5.2 Pass Stones

    Some rules use pass stones. A passing player adds one own
    stone to the prisoners. As a consequence, captures before
    the game end can be resolved in alternation without any loss
    because any not answered approach move is compensated by one
    pass stone. With traditional territory scoring that uses no
    pass stones definition problems arise due to this missing
    option. Modern territory scoring or equivalence scoring use
    pass stones.

    5.3 Equivalence

    Area scoring and territory scoring are close because either
    intersections occupied by own stones or opposing prisoners
    are used. Essentially, every prisoner is a stone removed
    from some intersection. For area it scores one point less
    for the stone's player while for territory it scores one
    point more for his opponent. This is equal. Exact equality
    for the entire game must also consider passes by using pass
    stones and an equal number of moves by requiring white to
    pass last. This is done by equivalence scoring.

    5.4 Meaning of Agreement Removals

    Removals in an agreement phase under area scoring are fair
    because they may as well occur in alternation. Removing a
    stone due to agreement includes its then empty intersection
    and all adjacent empty intersections in the score. Removing
    a stone by means of alternation includes its then empty
    intersection and all adjacent newly occupied intersections
    in the score. -
    With traditional territory scoring this is not possible
    since stones on the board do not score. Thus final captures
    must occur after the game end due to attempted definitions
    in the rules.

    5.5 Practical Scoring Differences

    Since area scoring and modern territory scoring using pass
    stones are equal, correct play is the same for both. Apart
    from Japanese rules exceptions like not scoring empty
    intersections especially in asymmetrical coexistences or
    like a pass-for-ko-rule, traditional territory scoring can
    make a different winner in practically ca. every 10000th
    even game. This is so rare because of a parity feature
    combined with a scarcely odd number of intersections that
    are in coexistences but do not score for area at the game
    end. With area scoring a komi change from 1.5, 3.5, 5.5, ...
    to 2.5, 4.5, 6.5, ... almost always would not change the
    winner. So altough occupying the last empty intersections
    that would otherwise not score just before a game stop gains
    one point each, alternately doing so leaves a total
    advantage of at most one point. Due to the parity feature
    the player to get it is predetermined when this occupation
    starts. More importantly, one final ko is worth 1 point under
    traditional territory scoring but 2 or rarely 4 points under
    area scoring. Rare one-sided points in coexistences provide
    only area. Other practical differences are even rarer. Cute
    players include the stones in their endgame value counts
    during the middle of an area scoring game.

    5.6 Stone Scoring

    In ancient times stone scoring was popular. Only stones on
    the board are scored. Thus empty intersections surrounded by
    own stones are filled until necessary so called eyes remain.
    Disconnected stones require more eyes in total, the so
    called group tax.

    5.7 Old Ing Scoring

    Old Ing rules allowed fractional scores by assigning points
    to neutral empty regions due to the percentage of black and
    white stones surrounding every region.

    5.8 Primitive Rules

    They do not have passes. Alternation ends when a player
    loses due to no legal play. Games can be extremely long and
    include special strategies, so called pass fights. Primitive
    rules (also called no pass rules or Conway rules) can be
    useful in mathematics.

    5.9 Tradition

    Historically, exceptions arose, which some like as such
    especially together with Japanese style rules. So called
    sekis are excluded from the score. Special positions, termed
    precedents, have special rules. Modern Japanese rules have
    generalized a lot of them by a pass-for-ko-rule. After the
    game stop or after the game end and particularly in
    hypothetical play a stone captured in a possible 2-play cycle
    may not be recaptured unless before a pass is made that
    specifies the particular 2-play cycle.

    5.10 Positional / Situational Superko

    Positional superko prohibits a play that recreates a position.
    Situational superko refers to the situation, i.e. to the
    position together with the right to move. So a play is
    prohibited if it recreates a position while the same player
    has the right to move. In practice the differences are
    extremely rare.

    5.11 Handicap Recompensation

    With area scoring handicap stones beyond the first provide
    a potential extra area of one point per handicap stone. Komi
    for white may consider this. Recompensation, H-1 points for H
    handicap stones, is virtually only used together with
    American rules.

    5.12 Mathematics

    Go is a complete information game, i.e. at every move each
    player knows the entire game situation. Hence theoretically
    an algorithm could determine perfect play. However, due to
    the complexity of the game with N intersections, for which
    it is provably impossible to devise a polynomial time
    solution, perfect play or ideal komi are unknown. What one
    does know is that in a game without komi the first player wins
    or ties and that perfect play is independent of set komi. Many
    other propositions have been discovered, some of which
    describe the relation between area and territory scoring, solve
    tiny endgame positions or cyclical behaviour. -
    Go is a very complex game! According to John Tromp, the number
    of legal positions is:

    208168199381979984699478633344862770286522453884530548425 639456820927419612738015378525648451698519643907259916015 628128546089888314427129715319317557736620397247064840935

    For positional superko, no passes, and no resignation, the
    number of possible games is smaller than N**L(N) because L(N)
    also restricts the maximal number of moves per game and there
    are at most N possible intersections per move. (The sign ** is
    a text file notation for "to the power".) -
    Extremely modest estimates look like 10**N, which is based on
    an assumption of 10 reasonable intersections per move. A
    popular estimate for 19x19 go is 10**761, which must have
    originated from a typo and should be 10**361, if at all...
    These types of estimates are so popular because humans cannot
    even imagine the suggested number of atoms in the universe,
    10**80. For comparison, 3**361 is ca. 10**172.

    6 TOURNAMENT RULES

    6.1 Special Game Ends

    If the score considering the komi is zero, then the game is a
    tie and should be treated as 0.5 won games for each. Special
    rules or undue behaviour like sincere lateness might result
    in a referee declaring a win by forfeit, 0:0, or 1:1,
    whichever is most appropriate.

    6.2 Tournament Systems

    A tournament might consist of several stages, of which each
    has a seed and a system. A seed appropriately restricts
    participation, e.g. due to qualification. The most important
    systems are match, league, knockout, Swiss, McMahon. There
    are many others and hybrids. A system must fit the aims of a
    tournament. A sufficient number of rounds, a proper seed,
    and colour variation ensure a fair determination of the best
    player. -
    A match takes place between two players that either play a
    set number of games to see who wins more or a maximal number
    of games to see who wins a predetermined number of games
    first. In a league a small, usually even number of players
    performs a round-robin tournament, so that in each round all
    players play and every two players play against each other,
    one game e.g. A knockout preferably starts with a number of
    players that is a power of two. Losing players are eliminated,
    winning players continue until the winner remains. -
    In a Swiss system before each round each player's achieved
    number of wins is used to pair players with equal numbers as
    far as possible. So all players play all rounds and some time
    the best player will emerge. However, with greatly varying
    strengths too many rounds would be needed. So Swiss is only
    useful for particular events or handicap tournaments.
    McMahon is the refinement of Swiss. Before the start of the
    tournament all players are classified in rank groups, with
    ranks R from 0 to T. This means that one assumes a preceding
    Swiss tournament where every player has already won R games.
    Then in the McMahon tournament the strongest players, who
    deserve the rank T, compete for the top places. In practice,
    one uses a bar B, that is 1 or 2 ranks below T, so that all
    ranks above B are contracted to B and also players slightly
    weaker than the top players get their chance. All players in
    a McMahon play roughly equal opponents; if they win or lose,
    then the opponents will be stronger or weaker.

    6.3 Tie Breakers

    Tie breakers can refine pairings or results. Typically the
    first criterion is the number of wins (or McMahon points);
    all further criteria, if any, are tie breakers. They attempt
    a refinement where a low number of rounds and a tournament
    system do not guarantee sufficient distinction between
    players' achievements. However, they must be applied with
    care since they are only marginally better than coin tossing.
    Examples of tie breakers are direct comparison, which
    acknowledges the winner of a game between two players in
    question, and SOS, which is the Sum of Opponents' Scores. -
    The possible degree of quality of tie breakers is subject to
    discussion. It depends on tournament system, whether only the
    top or all players shall be distinguished, and other factors.
    An alternative to the usage of tie breakers for the final
    results ordering is issuing shared places for all players
    with the same number of wins (or McMahon points). - One must
    fairly assign tie breaker points for opponents missing in
    some round; enforcing participation is preferable especially
    for top players.

    6.4 Pairing

    Pairings must be fair, precise, and consider prior
    achievements during a tournament. One should consider colour
    balance and no pair twice, one might also aim at avoiding a
    pair of players from the same club or country, depending on
    a tournament's intentions. Pairings might be done manually
    in small tournaments; for most tournaments pairing programs
    should be used. These can create fair pairings convincingly,
    some even watch global balance.

    6.5 Thinking Times

    The age of killing each other by greater endurance has gone.
    Clocks are used to count each player's remaining thinking
    time. Typically, every game has a basic time and overtime
    periods. Exceeding a time limit loses a game. Basic time
    might be 9 hours for a professional top game, 10 minutes for
    a lightning game, or something in between that fits a
    tournament's intentions. An overtime period requires a fixed
    number of moves within a predetermined period, e.g. 1 move
    within 60 seconds. A move is finished by pressing the clock.
    - Many variants or other time systems exist, e.g., increasing
    numbers of moves in further overtime periods, penalty points
    for entering further periods, full usage of every overtime
    period, thinking time working like an hour glass, etc.

    6.6 Tournament Rules

    Every tournament uses an announced set of tournament rules.
    They especially specify the used set for the core rules of
    play, the tournament system, tie breakers, the pairing
    method, the winning criteria, compensation methods,
    thinking times, direction, jurisdiction, adjournment
    methods, penalities for being late, etc. Tournament rules
    often deal with details. Not everything can be predicted, so
    a sportsmanlike spirit is mentioned. Finally, it should be
    clear which of several rule sets takes precedence.

    6.7 Tournament Organization

    A regional tournament can be organized by a club. Big events
    can be held at the request of an association or federation,
    who also supervise. A tournament organization is responsible
    for providing a venue and playing material. It must be
    distinguished from the tournament director and his assistant
    directors, who perform the particular tasks of pairing,
    collecting results, and ensuring smooth running. Shared
    power furthermore demands independent referees.

    6.8 Jurisdiction

    Before the start of a tournament valid instances of a
    jurisdiction as well as the persons to be referees must be
    clear. Typically, for a tournament itself there is one
    referee as the first instance and a body of three referees
    as the second instance. For very peculiar cases a federation
    could have a third and final instance. Some tournament rules
    replace the second instance by a single person, called chief
    referee; to avoid confusion he ought not to judge as the
    first instance. Players should respect the referees' tough
    job of mediation or decision; referees should seriously
    enforce the rules.

    6.9 Prizes

    The first places of a tournament invoke major prizes. E.g.
    the first, second, third places might get 3/6, 2/6, 1/6 of
    the available money. In a tournament with many weaker
    players it is a good idea to provide some prizes for all
    other players that win most rounds as well. While prizes can
    be money, books, trophies, etc., one should remember that
    money is most universally accepted and trophies serve the
    media better than the winners. -
    On a related topic, a side event lottery must give equal
    chances to all participants. This is only achieved by using
    one lot for each.

    7 Links

    Most rules information, links, short rules: http://home.snafu.de/jasiek/rules.html

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Robert Jasiek@21:1/5 to All on Thu Dec 12 11:59:37 2019
    Title: Rules FAQ
    Author: Robert Jasiek <jasiek@snafu.de>
    Frequency: monthly
    Last Update: 2017-10-13; First Day: 1999-04-12
    Distribution: rec.games.go
    Copyright: free non-commercial usage for promotion

    0 CONTENTS

    1 Purpose of this Paper
    2 Information for Beginners
    3 Important Concepts
    4 Particular Rules
    5 Troublesome Details
    6 Tournament Rules
    7 Links

    1 PURPOSE OF THIS PAPER

    This paper is a basic reference for important rules terms,
    rules, and tournament rules. Beginners should read
    especially Chapters 2 and 3, players Chapters 3 to 5,
    tournament players and organizers Chapter 6.

    2 INFORMATION FOR BEGINNERS
    2.1 What Must I Know as a Beginner?

    The game is played on a grid board. Typically it has 19x19
    intersections, but 9x9 are also fine. Two players compete.
    The first player uses black stones, the other white.

    The players alternate. A player may play or pass. Playing
    is putting one's own stone on an empty intersection and
    removing any surrounded opposing stones. To avoid
    cycles, a play may not recreate any prior configuration of
    all stones on the board.

    Two successive passes end the game. Then the player with
    more intersections wins. Intersections are his if only his
    stones occupy or surround them.

    2.2 Which Rules do I Need as a Beginner?

    You can play with short rules as in 2.1. Other rules may
    be different, but the game is the same, i. e. strategy,
    tactics, and the score do not change. Extremely rare
    exceptions confirm this rule.

    The winner can be determined by area or by territory.
    Either includes empty intersections surrounded only by own
    stones. While area adds intersections occupied by own
    stones, territory adds opposing prisoners instead.

    All rules, except short rules, have further phases after
    alternation and before scoring. Towards a game end it is
    often clear which stones will be removed. The additional
    phases allow the players to agree on which stones shall be
    removed. Thereby final removals do not require alternation.

    Whether you score by area or by territory or whether you
    remove by alternation or by agreement should mainly depend
    on which rules are used by people you play with.

    2.3 Which Rules Should I Teach?

    One possibility is to use a board with 9x9 intersections,
    short rules as in 2.1, and count each player's score by
    using a finger to scan the board for his intersections.

    3 IMPORTANT CONCEPTS

    While strategy and tactics virtually remain the same,
    concepts vary in different rules. However, the following
    gives a comprehensive overview on standard terms.

    3.1 Stone, String

    The physical device that colours one intersection in a
    play is a STONE. Two intersections of the board are
    ADJACENT if they have a line but no intersection between
    them. Two intersections with either black, white, or no
    stones on them are CONNECTED if they are adjacent or if
    there is a chain of adjacent intersections of their type
    between them. A REGION consists of an intersection and
    any intersections connected to it. A black or white
    region is called a STRING.

    3.2 Surrounded

    An intersection of one colour is SURROUNDED by another
    colour if each leaving path reaches the other colour first
    after the one colour. Hereby it can only be surrounded
    black by white, white by black, empty by black, or empty
    by white. A region can be surrounded. For strings there is
    an alternative notion of no liberty (or breath). A LIBERTY
    of a string is an empty intersection adjacent to it. Thus
    a string is surrounded if and only if it has no liberty.

    3.3 Removal, Suicide

    A removal empties the intersections of surrounded stones
    if there are any. Hereby removal of opposing stones is
    executed first, if necessary. Rules may either require or
    forbid removal of own stones. This is called suicide or no
    suicide. In practice, suicide might be used for so called ko
    fights or in capturing races.

    3.4 Capture, Prisoner

    Rules that score territory call a removal a capture
    because all removed stones are seriously kept as prisoners.

    3.5 Move, Play, Pass

    The players have alternate turns. On each turn a player makes
    a move that is either a play or a pass. A play places one's
    own stone on an empty intersection. It can then include
    removal of surrounded stones, if any. A pass merely continues
    alternation by giving the opponent the next turn.

    3.6 Compensation

    The first move advantage by black can be compensated by
    compensation points (komi) that are added to the white score
    after the game end. Komi can be adjusted by 0.5 to avoid
    ties. Today integer values for komi for 19x19 boards
    typically range between 5 and 7. For 13x13 boards one should
    use 8, for 9x9 boards 6; however, there is no real consensus
    for small board komi values yet. -
    A weaker player (black) can get the right to place an agreed
    number of compensation stones (handicap) before white's first
    play. Rules may allow free or fixed handicap. Free handicap
    does not apply any restriction. Fixed handicap requires
    traditional placement on set intersections.

    3.7 Phases

    Normally, a game consists of the phases alternation,
    agreement, scoring. A game stop is between alternation and
    agreement, the game end is between agreement and scoring,
    and after scoring both players accept the counted score as
    the result. The main part of the game is the alternation
    phase. Special rules are invoked after it. Typically, two
    successive passes in alternation are the game stop and start
    the agreement phase. In it the players may agree on strings
    to be removed. If they agree, then they remove those strings
    from the board; this ends the game. Sometimes they might
    disagree, then no strings are removed but alternation is
    resumed as if the last game stop did not occur.

    3.8 Recreation

    The position is the pattern of black and white stones on the
    board. Without extra rule a position might be repeated
    infinitely. The easiest rule to prohibit this says: A play
    may not recreate a position. This refers to positions after
    completion of plays, i.e. after possible removals. The rule
    is called "superko". -
    Some rules use concepts different from superko. They combine
    a "2-play rule" with a "long cycle rule". The first says:
    Two successive plays may not recreate a position. The second
    says: If a position is recreated after more than two moves,
    then the game ends either immediately or, as a variant, as
    soon as the players agree, with the result "without result".
    In practice the 2-play rule is sufficient for almost all
    cases. It handles the relevant standard pattern of two
    adjacent intersections. For superko this is just a special
    application.

    3.9 Scoring

    The score is the result after the game end as defined by
    the rules. There are two different scoring methods: area
    scoring and territory scoring. Rules use one of them. Both
    give the same result in almost all cases and both evaluate
    the difference of the black and the white scores. A player's
    AREA score is the sum of intersections with own stones and
    of empty intersections surrounded only by own stones. Simply
    speaking, a player's TERRITORY score is the sum of empty
    intersections surrounded only by own stones and of prisoners
    of opposing colour. With both scoring methods empty
    intersections that are not surrounded by either black or
    white are neutral.

    3.10 Counting

    A score must be determined by some mechanical procedure in
    practice; this is called counting. There are various methods.
    Some rules prescribe one. A possible method is to use one's
    finger to count point by point. Other methods rearrange a lot
    of stones on the board.

    4 PARTICULAR RULES

    Rules vary extremely. However, in practice they often give
    the same result.

    4.1 Short Rules

    Examples of short rules are the Simple Rules or the
    Tromp-Taylor rules. They have no game stop and no agreement.
    Both are superfluous since necessary removals may already be
    performed in the alternation. Two successive passes end the
    game that is scored then. Short rules use area scoring,
    superko, and suicide. Further settings are left for
    tournament rules.

    4.2 American Rules

    These are used by the American Go Association. They use
    situational superko, no suicide, and 7.5 komi. They permit
    free or fixed handicap. Their most remarkable feature is to
    allow one of area scoring or territory scoring. Herefore
    pass stones (one prisoner compensates each pass) and white
    moving last always ensure the same result, regardless of the
    applied scoring method.

    4.3 Chinese Rules

    These are used in continental China and sometimes in other
    countries. Area scoring and no suicide are used.

    4.3.1 Official Chinese Rules

    In practice, ko rules roughly amount to a 2-play rule and a
    long cycle rule. The mentioned superko is overridden. The
    counting is a sophisticated half counting, where empty
    intersections and then after rearrangements stones of one
    colour are added to be compared with half the non-neutral
    intersections. The komi as a half komi is 3.75. In full
    counting, counts and komi would be twice as big.

    4.3.2 Simplified Chinese Rules

    Positional superko is used. A counting method is not
    prescribed. The full komi should be 7.5.

    4.4 Japanese Rules

    The differences mainly affect handling of late game phases
    but often do not alter scores. Japanese rules use some
    traditional territory scoring that attempts to exclude so
    called sekis. No suicide applies. The core of the ko rules
    is a 2-play rule and a long cycle rule. Typically, komi is
    6.5. Fixed handicap should be used. The counting is a
    sophisticated rearrangement of empty intersections and
    filling-in of prisoners.

    4.4.1 Game Finishing Process

    A game finishes with the following process: 1) So called
    dame (neutral points) and defensive moves (necessary
    connections etc. due to occupied dame) are filled.
    2) The hypothetical analysis, which presumes perfect play,
    determines so called life or death of each string and the
    scoring intersections. 3) Without making any approach moves,
    dead stones are removed from scoring intersections and added
    to the prisoners. 4) The score is counted. (2) and (3) do not
    allow to play out life and death since actually filling
    intersections costs points in Japanese rules.

    4.4.2 Official Japanese Rules

    There are the Japanese 1989 Rules, which are used in Japan
    and elsewhere, and the World Amateur Go Championships Rules,
    which are used in some particular tournaments. Korean rules
    are similar to Japanese rules but have a very different text
    and differ in rare positions. Official Japanese rules are
    very incomplete and have messy late game phases. E.g., the
    Japanese 1989 Rules allow filling of dame during alternation,
    after it, or both and have a so called ko-pass-rule for the
    hypothetical analysis. Now professional Japanese rules are
    explained precisely by a rules expert's interpretation called
    "the Japanese 2003 Rules".

    4.4.3 Simplified Japanese Rules

    As a recent invention, they are not used yet. They are
    complete and have clear late game phases. Filling of dame is
    done during alternation.

    4.4.4 Verbal Japanese Rules

    They are used for informal games in many countries and
    undefined, except that the game finishing process is used.
    In a tournament without any official rules of play, disputes
    are not solved due to the rules but with a referee.

    4.5 Ing Rules

    Ing rules use area scoring, suicide, 8 komi with black
    winning ties, and free handicap.

    4.5.1 Official Ing Rules

    The ko rules are a mess but somehow resemble superko.
    Details could fill books. The late game phases are specified
    insufficiently. The peculiar counting method requires 180
    stones of each colour throughout the game, fills any stones
    on the board after the game end, and leaves exactly one
    empty intersection, which determines the winner. The
    official rules are used in professional Taiwanese and some
    sponsored tournaments. Taiwanese amateurs have their own
    rules.

    4.5.2 Simplified Ing Rules

    Positional superko is used. A counting method is not
    prescribed. The late game phases are specified clearly. The
    simplified rules are used in EGF tournaments that are said
    to use Ing rules.

    4.6 New Zealand Rules

    Area scoring, suicide, situational superko, 7 komi, and free
    handicap are used.

    4.7 Go Server Rules

    Every go server has its own and often complicated rules, if
    any, so they cannot be given in detail here. Concerning
    "IGS rules", territory scoring, no suicide, a 2-play rule,
    fixed handicap, three game stopping passes, and captures in
    an agreement phase are used. Details about agreements and
    long cycles are not specified and lead to adjourned games in
    case of doubt. Komi is suggested but may be altered. Counting
    is automatic. "Yahoo" has territory scoring, no suicide, a
    2-play rule, two game stopping passes; long cycles and
    disagreements are not handled properly. On "email servers"
    players must agree on any rules. -
    Typically territory scoring on a go server means that neither
    points in any sekis are excluded nor pass stones are used.
    Thus while the Japanese seki exception is abandoned,
    disagreements about removals may lead to games without result
    since playing out can cost points.

    4.8 International Rules

    The international mailing list go-rules has proposed
    international rules, however, none are adopted yet. The core
    rules of play shall be clear, complete, and correct.
    Currently alternative texts are offered for suicide,
    recreation, and scoring. Especially unification of scoring
    methods is advocated.

    4.9 EGF Rules

    The EGF uses the Simplified Ing Rules with 8 komi (black
    wins ties) in Ing sponsored tournaments and the Nihon Kiin
    1989 Rules with 6.5 komi in Japanese/Korean sponsored
    tournaments. If significantly the European Go Championship
    has both kinds of sponsors, then boards 1-16 use the Nihon
    Kiin 1989 Rules and boards 17+ the Simplified Ing Rules.
    However, time settings depend on ranks.

    5 TROUBLESOME DETAILS

    5.1 Colour Choice

    In even games typically the colours are randomly chosen. In
    handicap games black receives the handicap stones. -
    A manual method for randomly choosing colours is called
    nigiri. The older player hides a number of white stones
    taken from the bowl, the opponent takes one or two black
    stones to guess the parity, and the parity of the number of
    white stones is revealed. If the opponent guesses right,
    then he takes black, else he takes white.

    5.2 Pass Stones

    Some rules use pass stones. A passing player adds one own
    stone to the prisoners. As a consequence, captures before
    the game end can be resolved in alternation without any loss
    because any not answered approach move is compensated by one
    pass stone. With traditional territory scoring that uses no
    pass stones definition problems arise due to this missing
    option. Modern territory scoring or equivalence scoring use
    pass stones.

    5.3 Equivalence

    Area scoring and territory scoring are close because either
    intersections occupied by own stones or opposing prisoners
    are used. Essentially, every prisoner is a stone removed
    from some intersection. For area it scores one point less
    for the stone's player while for territory it scores one
    point more for his opponent. This is equal. Exact equality
    for the entire game must also consider passes by using pass
    stones and an equal number of moves by requiring white to
    pass last. This is done by equivalence scoring.

    5.4 Meaning of Agreement Removals

    Removals in an agreement phase under area scoring are fair
    because they may as well occur in alternation. Removing a
    stone due to agreement includes its then empty intersection
    and all adjacent empty intersections in the score. Removing
    a stone by means of alternation includes its then empty
    intersection and all adjacent newly occupied intersections
    in the score. -
    With traditional territory scoring this is not possible
    since stones on the board do not score. Thus final captures
    must occur after the game end due to attempted definitions
    in the rules.

    5.5 Practical Scoring Differences

    Since area scoring and modern territory scoring using pass
    stones are equal, correct play is the same for both. Apart
    from Japanese rules exceptions like not scoring empty
    intersections especially in asymmetrical coexistences or
    like a pass-for-ko-rule, traditional territory scoring can
    make a different winner in practically ca. every 10000th
    even game. This is so rare because of a parity feature
    combined with a scarcely odd number of intersections that
    are in coexistences but do not score for area at the game
    end. With area scoring a komi change from 1.5, 3.5, 5.5, ...
    to 2.5, 4.5, 6.5, ... almost always would not change the
    winner. So altough occupying the last empty intersections
    that would otherwise not score just before a game stop gains
    one point each, alternately doing so leaves a total
    advantage of at most one point. Due to the parity feature
    the player to get it is predetermined when this occupation
    starts. More importantly, one final ko is worth 1 point under
    traditional territory scoring but 2 or rarely 4 points under
    area scoring. Rare one-sided points in coexistences provide
    only area. Other practical differences are even rarer. Cute
    players include the stones in their endgame value counts
    during the middle of an area scoring game.

    5.6 Stone Scoring

    In ancient times stone scoring was popular. Only stones on
    the board are scored. Thus empty intersections surrounded by
    own stones are filled until necessary so called eyes remain.
    Disconnected stones require more eyes in total, the so
    called group tax.

    5.7 Old Ing Scoring

    Old Ing rules allowed fractional scores by assigning points
    to neutral empty regions due to the percentage of black and
    white stones surrounding every region.

    5.8 Primitive Rules

    They do not have passes. Alternation ends when a player
    loses due to no legal play. Games can be extremely long and
    include special strategies, so called pass fights. Primitive
    rules (also called no pass rules or Conway rules) can be
    useful in mathematics.

    5.9 Tradition

    Historically, exceptions arose, which some like as such
    especially together with Japanese style rules. So called
    sekis are excluded from the score. Special positions, termed
    precedents, have special rules. Modern Japanese rules have
    generalized a lot of them by a pass-for-ko-rule. After the
    game stop or after the game end and particularly in
    hypothetical play a stone captured in a possible 2-play cycle
    may not be recaptured unless before a pass is made that
    specifies the particular 2-play cycle.

    5.10 Positional / Situational Superko

    Positional superko prohibits a play that recreates a position.
    Situational superko refers to the situation, i.e. to the
    position together with the right to move. So a play is
    prohibited if it recreates a position while the same player
    has the right to move. In practice the differences are
    extremely rare.

    5.11 Handicap Recompensation

    With area scoring handicap stones beyond the first provide
    a potential extra area of one point per handicap stone. Komi
    for white may consider this. Recompensation, H-1 points for H
    handicap stones, is virtually only used together with
    American rules.

    5.12 Mathematics

    Go is a complete information game, i.e. at every move each
    player knows the entire game situation. Hence theoretically
    an algorithm could determine perfect play. However, due to
    the complexity of the game with N intersections, for which
    it is provably impossible to devise a polynomial time
    solution, perfect play or ideal komi are unknown. What one
    does know is that in a game without komi the first player wins
    or ties and that perfect play is independent of set komi. Many
    other propositions have been discovered, some of which
    describe the relation between area and territory scoring, solve
    tiny endgame positions or cyclical behaviour. -
    Go is a very complex game! According to John Tromp, the number
    of legal positions is:

    208168199381979984699478633344862770286522453884530548425 639456820927419612738015378525648451698519643907259916015 628128546089888314427129715319317557736620397247064840935

    For positional superko, no passes, and no resignation, the
    number of possible games is smaller than N**L(N) because L(N)
    also restricts the maximal number of moves per game and there
    are at most N possible intersections per move. (The sign ** is
    a text file notation for "to the power".) -
    Extremely modest estimates look like 10**N, which is based on
    an assumption of 10 reasonable intersections per move. A
    popular estimate for 19x19 go is 10**761, which must have
    originated from a typo and should be 10**361, if at all...
    These types of estimates are so popular because humans cannot
    even imagine the suggested number of atoms in the universe,
    10**80. For comparison, 3**361 is ca. 10**172.

    6 TOURNAMENT RULES

    6.1 Special Game Ends

    If the score considering the komi is zero, then the game is a
    tie and should be treated as 0.5 won games for each. Special
    rules or undue behaviour like sincere lateness might result
    in a referee declaring a win by forfeit, 0:0, or 1:1,
    whichever is most appropriate.

    6.2 Tournament Systems

    A tournament might consist of several stages, of which each
    has a seed and a system. A seed appropriately restricts
    participation, e.g. due to qualification. The most important
    systems are match, league, knockout, Swiss, McMahon. There
    are many others and hybrids. A system must fit the aims of a
    tournament. A sufficient number of rounds, a proper seed,
    and colour variation ensure a fair determination of the best
    player. -
    A match takes place between two players that either play a
    set number of games to see who wins more or a maximal number
    of games to see who wins a predetermined number of games
    first. In a league a small, usually even number of players
    performs a round-robin tournament, so that in each round all
    players play and every two players play against each other,
    one game e.g. A knockout preferably starts with a number of
    players that is a power of two. Losing players are eliminated,
    winning players continue until the winner remains. -
    In a Swiss system before each round each player's achieved
    number of wins is used to pair players with equal numbers as
    far as possible. So all players play all rounds and some time
    the best player will emerge. However, with greatly varying
    strengths too many rounds would be needed. So Swiss is only
    useful for particular events or handicap tournaments.
    McMahon is the refinement of Swiss. Before the start of the
    tournament all players are classified in rank groups, with
    ranks R from 0 to T. This means that one assumes a preceding
    Swiss tournament where every player has already won R games.
    Then in the McMahon tournament the strongest players, who
    deserve the rank T, compete for the top places. In practice,
    one uses a bar B, that is 1 or 2 ranks below T, so that all
    ranks above B are contracted to B and also players slightly
    weaker than the top players get their chance. All players in
    a McMahon play roughly equal opponents; if they win or lose,
    then the opponents will be stronger or weaker.

    6.3 Tie Breakers

    Tie breakers can refine pairings or results. Typically the
    first criterion is the number of wins (or McMahon points);
    all further criteria, if any, are tie breakers. They attempt
    a refinement where a low number of rounds and a tournament
    system do not guarantee sufficient distinction between
    players' achievements. However, they must be applied with
    care since they are only marginally better than coin tossing.
    Examples of tie breakers are direct comparison, which
    acknowledges the winner of a game between two players in
    question, and SOS, which is the Sum of Opponents' Scores. -
    The possible degree of quality of tie breakers is subject to
    discussion. It depends on tournament system, whether only the
    top or all players shall be distinguished, and other factors.
    An alternative to the usage of tie breakers for the final
    results ordering is issuing shared places for all players
    with the same number of wins (or McMahon points). - One must
    fairly assign tie breaker points for opponents missing in
    some round; enforcing participation is preferable especially
    for top players.

    6.4 Pairing

    Pairings must be fair, precise, and consider prior
    achievements during a tournament. One should consider colour
    balance and no pair twice, one might also aim at avoiding a
    pair of players from the same club or country, depending on
    a tournament's intentions. Pairings might be done manually
    in small tournaments; for most tournaments pairing programs
    should be used. These can create fair pairings convincingly,
    some even watch global balance.

    6.5 Thinking Times

    The age of killing each other by greater endurance has gone.
    Clocks are used to count each player's remaining thinking
    time. Typically, every game has a basic time and overtime
    periods. Exceeding a time limit loses a game. Basic time
    might be 9 hours for a professional top game, 10 minutes for
    a lightning game, or something in between that fits a
    tournament's intentions. An overtime period requires a fixed
    number of moves within a predetermined period, e.g. 1 move
    within 60 seconds. A move is finished by pressing the clock.
    - Many variants or other time systems exist, e.g., increasing
    numbers of moves in further overtime periods, penalty points
    for entering further periods, full usage of every overtime
    period, thinking time working like an hour glass, etc.

    6.6 Tournament Rules

    Every tournament uses an announced set of tournament rules.
    They especially specify the used set for the core rules of
    play, the tournament system, tie breakers, the pairing
    method, the winning criteria, compensation methods,
    thinking times, direction, jurisdiction, adjournment
    methods, penalities for being late, etc. Tournament rules
    often deal with details. Not everything can be predicted, so
    a sportsmanlike spirit is mentioned. Finally, it should be
    clear which of several rule sets takes precedence.

    6.7 Tournament Organization

    A regional tournament can be organized by a club. Big events
    can be held at the request of an association or federation,
    who also supervise. A tournament organization is responsible
    for providing a venue and playing material. It must be
    distinguished from the tournament director and his assistant
    directors, who perform the particular tasks of pairing,
    collecting results, and ensuring smooth running. Shared
    power furthermore demands independent referees.

    6.8 Jurisdiction

    Before the start of a tournament valid instances of a
    jurisdiction as well as the persons to be referees must be
    clear. Typically, for a tournament itself there is one
    referee as the first instance and a body of three referees
    as the second instance. For very peculiar cases a federation
    could have a third and final instance. Some tournament rules
    replace the second instance by a single person, called chief
    referee; to avoid confusion he ought not to judge as the
    first instance. Players should respect the referees' tough
    job of mediation or decision; referees should seriously
    enforce the rules.

    6.9 Prizes

    The first places of a tournament invoke major prizes. E.g.
    the first, second, third places might get 3/6, 2/6, 1/6 of
    the available money. In a tournament with many weaker
    players it is a good idea to provide some prizes for all
    other players that win most rounds as well. While prizes can
    be money, books, trophies, etc., one should remember that
    money is most universally accepted and trophies serve the
    media better than the winners. -
    On a related topic, a side event lottery must give equal
    chances to all participants. This is only achieved by using
    one lot for each.

    7 Links

    Most rules information, links, short rules: http://home.snafu.de/jasiek/rules.html

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Robert Jasiek@21:1/5 to All on Wed Feb 12 04:59:38 2020
    Title: Rules FAQ
    Author: Robert Jasiek <jasiek@snafu.de>
    Frequency: monthly
    Last Update: 2017-10-13; First Day: 1999-04-12
    Distribution: rec.games.go
    Copyright: free non-commercial usage for promotion

    0 CONTENTS

    1 Purpose of this Paper
    2 Information for Beginners
    3 Important Concepts
    4 Particular Rules
    5 Troublesome Details
    6 Tournament Rules
    7 Links

    1 PURPOSE OF THIS PAPER

    This paper is a basic reference for important rules terms,
    rules, and tournament rules. Beginners should read
    especially Chapters 2 and 3, players Chapters 3 to 5,
    tournament players and organizers Chapter 6.

    2 INFORMATION FOR BEGINNERS
    2.1 What Must I Know as a Beginner?

    The game is played on a grid board. Typically it has 19x19
    intersections, but 9x9 are also fine. Two players compete.
    The first player uses black stones, the other white.

    The players alternate. A player may play or pass. Playing
    is putting one's own stone on an empty intersection and
    removing any surrounded opposing stones. To avoid
    cycles, a play may not recreate any prior configuration of
    all stones on the board.

    Two successive passes end the game. Then the player with
    more intersections wins. Intersections are his if only his
    stones occupy or surround them.

    2.2 Which Rules do I Need as a Beginner?

    You can play with short rules as in 2.1. Other rules may
    be different, but the game is the same, i. e. strategy,
    tactics, and the score do not change. Extremely rare
    exceptions confirm this rule.

    The winner can be determined by area or by territory.
    Either includes empty intersections surrounded only by own
    stones. While area adds intersections occupied by own
    stones, territory adds opposing prisoners instead.

    All rules, except short rules, have further phases after
    alternation and before scoring. Towards a game end it is
    often clear which stones will be removed. The additional
    phases allow the players to agree on which stones shall be
    removed. Thereby final removals do not require alternation.

    Whether you score by area or by territory or whether you
    remove by alternation or by agreement should mainly depend
    on which rules are used by people you play with.

    2.3 Which Rules Should I Teach?

    One possibility is to use a board with 9x9 intersections,
    short rules as in 2.1, and count each player's score by
    using a finger to scan the board for his intersections.

    3 IMPORTANT CONCEPTS

    While strategy and tactics virtually remain the same,
    concepts vary in different rules. However, the following
    gives a comprehensive overview on standard terms.

    3.1 Stone, String

    The physical device that colours one intersection in a
    play is a STONE. Two intersections of the board are
    ADJACENT if they have a line but no intersection between
    them. Two intersections with either black, white, or no
    stones on them are CONNECTED if they are adjacent or if
    there is a chain of adjacent intersections of their type
    between them. A REGION consists of an intersection and
    any intersections connected to it. A black or white
    region is called a STRING.

    3.2 Surrounded

    An intersection of one colour is SURROUNDED by another
    colour if each leaving path reaches the other colour first
    after the one colour. Hereby it can only be surrounded
    black by white, white by black, empty by black, or empty
    by white. A region can be surrounded. For strings there is
    an alternative notion of no liberty (or breath). A LIBERTY
    of a string is an empty intersection adjacent to it. Thus
    a string is surrounded if and only if it has no liberty.

    3.3 Removal, Suicide

    A removal empties the intersections of surrounded stones
    if there are any. Hereby removal of opposing stones is
    executed first, if necessary. Rules may either require or
    forbid removal of own stones. This is called suicide or no
    suicide. In practice, suicide might be used for so called ko
    fights or in capturing races.

    3.4 Capture, Prisoner

    Rules that score territory call a removal a capture
    because all removed stones are seriously kept as prisoners.

    3.5 Move, Play, Pass

    The players have alternate turns. On each turn a player makes
    a move that is either a play or a pass. A play places one's
    own stone on an empty intersection. It can then include
    removal of surrounded stones, if any. A pass merely continues
    alternation by giving the opponent the next turn.

    3.6 Compensation

    The first move advantage by black can be compensated by
    compensation points (komi) that are added to the white score
    after the game end. Komi can be adjusted by 0.5 to avoid
    ties. Today integer values for komi for 19x19 boards
    typically range between 5 and 7. For 13x13 boards one should
    use 8, for 9x9 boards 6; however, there is no real consensus
    for small board komi values yet. -
    A weaker player (black) can get the right to place an agreed
    number of compensation stones (handicap) before white's first
    play. Rules may allow free or fixed handicap. Free handicap
    does not apply any restriction. Fixed handicap requires
    traditional placement on set intersections.

    3.7 Phases

    Normally, a game consists of the phases alternation,
    agreement, scoring. A game stop is between alternation and
    agreement, the game end is between agreement and scoring,
    and after scoring both players accept the counted score as
    the result. The main part of the game is the alternation
    phase. Special rules are invoked after it. Typically, two
    successive passes in alternation are the game stop and start
    the agreement phase. In it the players may agree on strings
    to be removed. If they agree, then they remove those strings
    from the board; this ends the game. Sometimes they might
    disagree, then no strings are removed but alternation is
    resumed as if the last game stop did not occur.

    3.8 Recreation

    The position is the pattern of black and white stones on the
    board. Without extra rule a position might be repeated
    infinitely. The easiest rule to prohibit this says: A play
    may not recreate a position. This refers to positions after
    completion of plays, i.e. after possible removals. The rule
    is called "superko". -
    Some rules use concepts different from superko. They combine
    a "2-play rule" with a "long cycle rule". The first says:
    Two successive plays may not recreate a position. The second
    says: If a position is recreated after more than two moves,
    then the game ends either immediately or, as a variant, as
    soon as the players agree, with the result "without result".
    In practice the 2-play rule is sufficient for almost all
    cases. It handles the relevant standard pattern of two
    adjacent intersections. For superko this is just a special
    application.

    3.9 Scoring

    The score is the result after the game end as defined by
    the rules. There are two different scoring methods: area
    scoring and territory scoring. Rules use one of them. Both
    give the same result in almost all cases and both evaluate
    the difference of the black and the white scores. A player's
    AREA score is the sum of intersections with own stones and
    of empty intersections surrounded only by own stones. Simply
    speaking, a player's TERRITORY score is the sum of empty
    intersections surrounded only by own stones and of prisoners
    of opposing colour. With both scoring methods empty
    intersections that are not surrounded by either black or
    white are neutral.

    3.10 Counting

    A score must be determined by some mechanical procedure in
    practice; this is called counting. There are various methods.
    Some rules prescribe one. A possible method is to use one's
    finger to count point by point. Other methods rearrange a lot
    of stones on the board.

    4 PARTICULAR RULES

    Rules vary extremely. However, in practice they often give
    the same result.

    4.1 Short Rules

    Examples of short rules are the Simple Rules or the
    Tromp-Taylor rules. They have no game stop and no agreement.
    Both are superfluous since necessary removals may already be
    performed in the alternation. Two successive passes end the
    game that is scored then. Short rules use area scoring,
    superko, and suicide. Further settings are left for
    tournament rules.

    4.2 American Rules

    These are used by the American Go Association. They use
    situational superko, no suicide, and 7.5 komi. They permit
    free or fixed handicap. Their most remarkable feature is to
    allow one of area scoring or territory scoring. Herefore
    pass stones (one prisoner compensates each pass) and white
    moving last always ensure the same result, regardless of the
    applied scoring method.

    4.3 Chinese Rules

    These are used in continental China and sometimes in other
    countries. Area scoring and no suicide are used.

    4.3.1 Official Chinese Rules

    In practice, ko rules roughly amount to a 2-play rule and a
    long cycle rule. The mentioned superko is overridden. The
    counting is a sophisticated half counting, where empty
    intersections and then after rearrangements stones of one
    colour are added to be compared with half the non-neutral
    intersections. The komi as a half komi is 3.75. In full
    counting, counts and komi would be twice as big.

    4.3.2 Simplified Chinese Rules

    Positional superko is used. A counting method is not
    prescribed. The full komi should be 7.5.

    4.4 Japanese Rules

    The differences mainly affect handling of late game phases
    but often do not alter scores. Japanese rules use some
    traditional territory scoring that attempts to exclude so
    called sekis. No suicide applies. The core of the ko rules
    is a 2-play rule and a long cycle rule. Typically, komi is
    6.5. Fixed handicap should be used. The counting is a
    sophisticated rearrangement of empty intersections and
    filling-in of prisoners.

    4.4.1 Game Finishing Process

    A game finishes with the following process: 1) So called
    dame (neutral points) and defensive moves (necessary
    connections etc. due to occupied dame) are filled.
    2) The hypothetical analysis, which presumes perfect play,
    determines so called life or death of each string and the
    scoring intersections. 3) Without making any approach moves,
    dead stones are removed from scoring intersections and added
    to the prisoners. 4) The score is counted. (2) and (3) do not
    allow to play out life and death since actually filling
    intersections costs points in Japanese rules.

    4.4.2 Official Japanese Rules

    There are the Japanese 1989 Rules, which are used in Japan
    and elsewhere, and the World Amateur Go Championships Rules,
    which are used in some particular tournaments. Korean rules
    are similar to Japanese rules but have a very different text
    and differ in rare positions. Official Japanese rules are
    very incomplete and have messy late game phases. E.g., the
    Japanese 1989 Rules allow filling of dame during alternation,
    after it, or both and have a so called ko-pass-rule for the
    hypothetical analysis. Now professional Japanese rules are
    explained precisely by a rules expert's interpretation called
    "the Japanese 2003 Rules".

    4.4.3 Simplified Japanese Rules

    As a recent invention, they are not used yet. They are
    complete and have clear late game phases. Filling of dame is
    done during alternation.

    4.4.4 Verbal Japanese Rules

    They are used for informal games in many countries and
    undefined, except that the game finishing process is used.
    In a tournament without any official rules of play, disputes
    are not solved due to the rules but with a referee.

    4.5 Ing Rules

    Ing rules use area scoring, suicide, 8 komi with black
    winning ties, and free handicap.

    4.5.1 Official Ing Rules

    The ko rules are a mess but somehow resemble superko.
    Details could fill books. The late game phases are specified
    insufficiently. The peculiar counting method requires 180
    stones of each colour throughout the game, fills any stones
    on the board after the game end, and leaves exactly one
    empty intersection, which determines the winner. The
    official rules are used in professional Taiwanese and some
    sponsored tournaments. Taiwanese amateurs have their own
    rules.

    4.5.2 Simplified Ing Rules

    Positional superko is used. A counting method is not
    prescribed. The late game phases are specified clearly. The
    simplified rules are used in EGF tournaments that are said
    to use Ing rules.

    4.6 New Zealand Rules

    Area scoring, suicide, situational superko, 7 komi, and free
    handicap are used.

    4.7 Go Server Rules

    Every go server has its own and often complicated rules, if
    any, so they cannot be given in detail here. Concerning
    "IGS rules", territory scoring, no suicide, a 2-play rule,
    fixed handicap, three game stopping passes, and captures in
    an agreement phase are used. Details about agreements and
    long cycles are not specified and lead to adjourned games in
    case of doubt. Komi is suggested but may be altered. Counting
    is automatic. "Yahoo" has territory scoring, no suicide, a
    2-play rule, two game stopping passes; long cycles and
    disagreements are not handled properly. On "email servers"
    players must agree on any rules. -
    Typically territory scoring on a go server means that neither
    points in any sekis are excluded nor pass stones are used.
    Thus while the Japanese seki exception is abandoned,
    disagreements about removals may lead to games without result
    since playing out can cost points.

    4.8 International Rules

    The international mailing list go-rules has proposed
    international rules, however, none are adopted yet. The core
    rules of play shall be clear, complete, and correct.
    Currently alternative texts are offered for suicide,
    recreation, and scoring. Especially unification of scoring
    methods is advocated.

    4.9 EGF Rules

    The EGF uses the Simplified Ing Rules with 8 komi (black
    wins ties) in Ing sponsored tournaments and the Nihon Kiin
    1989 Rules with 6.5 komi in Japanese/Korean sponsored
    tournaments. If significantly the European Go Championship
    has both kinds of sponsors, then boards 1-16 use the Nihon
    Kiin 1989 Rules and boards 17+ the Simplified Ing Rules.
    However, time settings depend on ranks.

    5 TROUBLESOME DETAILS

    5.1 Colour Choice

    In even games typically the colours are randomly chosen. In
    handicap games black receives the handicap stones. -
    A manual method for randomly choosing colours is called
    nigiri. The older player hides a number of white stones
    taken from the bowl, the opponent takes one or two black
    stones to guess the parity, and the parity of the number of
    white stones is revealed. If the opponent guesses right,
    then he takes black, else he takes white.

    5.2 Pass Stones

    Some rules use pass stones. A passing player adds one own
    stone to the prisoners. As a consequence, captures before
    the game end can be resolved in alternation without any loss
    because any not answered approach move is compensated by one
    pass stone. With traditional territory scoring that uses no
    pass stones definition problems arise due to this missing
    option. Modern territory scoring or equivalence scoring use
    pass stones.

    5.3 Equivalence

    Area scoring and territory scoring are close because either
    intersections occupied by own stones or opposing prisoners
    are used. Essentially, every prisoner is a stone removed
    from some intersection. For area it scores one point less
    for the stone's player while for territory it scores one
    point more for his opponent. This is equal. Exact equality
    for the entire game must also consider passes by using pass
    stones and an equal number of moves by requiring white to
    pass last. This is done by equivalence scoring.

    5.4 Meaning of Agreement Removals

    Removals in an agreement phase under area scoring are fair
    because they may as well occur in alternation. Removing a
    stone due to agreement includes its then empty intersection
    and all adjacent empty intersections in the score. Removing
    a stone by means of alternation includes its then empty
    intersection and all adjacent newly occupied intersections
    in the score. -
    With traditional territory scoring this is not possible
    since stones on the board do not score. Thus final captures
    must occur after the game end due to attempted definitions
    in the rules.

    5.5 Practical Scoring Differences

    Since area scoring and modern territory scoring using pass
    stones are equal, correct play is the same for both. Apart
    from Japanese rules exceptions like not scoring empty
    intersections especially in asymmetrical coexistences or
    like a pass-for-ko-rule, traditional territory scoring can
    make a different winner in practically ca. every 10000th
    even game. This is so rare because of a parity feature
    combined with a scarcely odd number of intersections that
    are in coexistences but do not score for area at the game
    end. With area scoring a komi change from 1.5, 3.5, 5.5, ...
    to 2.5, 4.5, 6.5, ... almost always would not change the
    winner. So altough occupying the last empty intersections
    that would otherwise not score just before a game stop gains
    one point each, alternately doing so leaves a total
    advantage of at most one point. Due to the parity feature
    the player to get it is predetermined when this occupation
    starts. More importantly, one final ko is worth 1 point under
    traditional territory scoring but 2 or rarely 4 points under
    area scoring. Rare one-sided points in coexistences provide
    only area. Other practical differences are even rarer. Cute
    players include the stones in their endgame value counts
    during the middle of an area scoring game.

    5.6 Stone Scoring

    In ancient times stone scoring was popular. Only stones on
    the board are scored. Thus empty intersections surrounded by
    own stones are filled until necessary so called eyes remain.
    Disconnected stones require more eyes in total, the so
    called group tax.

    5.7 Old Ing Scoring

    Old Ing rules allowed fractional scores by assigning points
    to neutral empty regions due to the percentage of black and
    white stones surrounding every region.

    5.8 Primitive Rules

    They do not have passes. Alternation ends when a player
    loses due to no legal play. Games can be extremely long and
    include special strategies, so called pass fights. Primitive
    rules (also called no pass rules or Conway rules) can be
    useful in mathematics.

    5.9 Tradition

    Historically, exceptions arose, which some like as such
    especially together with Japanese style rules. So called
    sekis are excluded from the score. Special positions, termed
    precedents, have special rules. Modern Japanese rules have
    generalized a lot of them by a pass-for-ko-rule. After the
    game stop or after the game end and particularly in
    hypothetical play a stone captured in a possible 2-play cycle
    may not be recaptured unless before a pass is made that
    specifies the particular 2-play cycle.

    5.10 Positional / Situational Superko

    Positional superko prohibits a play that recreates a position.
    Situational superko refers to the situation, i.e. to the
    position together with the right to move. So a play is
    prohibited if it recreates a position while the same player
    has the right to move. In practice the differences are
    extremely rare.

    5.11 Handicap Recompensation

    With area scoring handicap stones beyond the first provide
    a potential extra area of one point per handicap stone. Komi
    for white may consider this. Recompensation, H-1 points for H
    handicap stones, is virtually only used together with
    American rules.

    5.12 Mathematics

    Go is a complete information game, i.e. at every move each
    player knows the entire game situation. Hence theoretically
    an algorithm could determine perfect play. However, due to
    the complexity of the game with N intersections, for which
    it is provably impossible to devise a polynomial time
    solution, perfect play or ideal komi are unknown. What one
    does know is that in a game without komi the first player wins
    or ties and that perfect play is independent of set komi. Many
    other propositions have been discovered, some of which
    describe the relation between area and territory scoring, solve
    tiny endgame positions or cyclical behaviour. -
    Go is a very complex game! According to John Tromp, the number
    of legal positions is:

    208168199381979984699478633344862770286522453884530548425 639456820927419612738015378525648451698519643907259916015 628128546089888314427129715319317557736620397247064840935

    For positional superko, no passes, and no resignation, the
    number of possible games is smaller than N**L(N) because L(N)
    also restricts the maximal number of moves per game and there
    are at most N possible intersections per move. (The sign ** is
    a text file notation for "to the power".) -
    Extremely modest estimates look like 10**N, which is based on
    an assumption of 10 reasonable intersections per move. A
    popular estimate for 19x19 go is 10**761, which must have
    originated from a typo and should be 10**361, if at all...
    These types of estimates are so popular because humans cannot
    even imagine the suggested number of atoms in the universe,
    10**80. For comparison, 3**361 is ca. 10**172.

    6 TOURNAMENT RULES

    6.1 Special Game Ends

    If the score considering the komi is zero, then the game is a
    tie and should be treated as 0.5 won games for each. Special
    rules or undue behaviour like sincere lateness might result
    in a referee declaring a win by forfeit, 0:0, or 1:1,
    whichever is most appropriate.

    6.2 Tournament Systems

    A tournament might consist of several stages, of which each
    has a seed and a system. A seed appropriately restricts
    participation, e.g. due to qualification. The most important
    systems are match, league, knockout, Swiss, McMahon. There
    are many others and hybrids. A system must fit the aims of a
    tournament. A sufficient number of rounds, a proper seed,
    and colour variation ensure a fair determination of the best
    player. -
    A match takes place between two players that either play a
    set number of games to see who wins more or a maximal number
    of games to see who wins a predetermined number of games
    first. In a league a small, usually even number of players
    performs a round-robin tournament, so that in each round all
    players play and every two players play against each other,
    one game e.g. A knockout preferably starts with a number of
    players that is a power of two. Losing players are eliminated,
    winning players continue until the winner remains. -
    In a Swiss system before each round each player's achieved
    number of wins is used to pair players with equal numbers as
    far as possible. So all players play all rounds and some time
    the best player will emerge. However, with greatly varying
    strengths too many rounds would be needed. So Swiss is only
    useful for particular events or handicap tournaments.
    McMahon is the refinement of Swiss. Before the start of the
    tournament all players are classified in rank groups, with
    ranks R from 0 to T. This means that one assumes a preceding
    Swiss tournament where every player has already won R games.
    Then in the McMahon tournament the strongest players, who
    deserve the rank T, compete for the top places. In practice,
    one uses a bar B, that is 1 or 2 ranks below T, so that all
    ranks above B are contracted to B and also players slightly
    weaker than the top players get their chance. All players in
    a McMahon play roughly equal opponents; if they win or lose,
    then the opponents will be stronger or weaker.

    6.3 Tie Breakers

    Tie breakers can refine pairings or results. Typically the
    first criterion is the number of wins (or McMahon points);
    all further criteria, if any, are tie breakers. They attempt
    a refinement where a low number of rounds and a tournament
    system do not guarantee sufficient distinction between
    players' achievements. However, they must be applied with
    care since they are only marginally better than coin tossing.
    Examples of tie breakers are direct comparison, which
    acknowledges the winner of a game between two players in
    question, and SOS, which is the Sum of Opponents' Scores. -
    The possible degree of quality of tie breakers is subject to
    discussion. It depends on tournament system, whether only the
    top or all players shall be distinguished, and other factors.
    An alternative to the usage of tie breakers for the final
    results ordering is issuing shared places for all players
    with the same number of wins (or McMahon points). - One must
    fairly assign tie breaker points for opponents missing in
    some round; enforcing participation is preferable especially
    for top players.

    6.4 Pairing

    Pairings must be fair, precise, and consider prior
    achievements during a tournament. One should consider colour
    balance and no pair twice, one might also aim at avoiding a
    pair of players from the same club or country, depending on
    a tournament's intentions. Pairings might be done manually
    in small tournaments; for most tournaments pairing programs
    should be used. These can create fair pairings convincingly,
    some even watch global balance.

    6.5 Thinking Times

    The age of killing each other by greater endurance has gone.
    Clocks are used to count each player's remaining thinking
    time. Typically, every game has a basic time and overtime
    periods. Exceeding a time limit loses a game. Basic time
    might be 9 hours for a professional top game, 10 minutes for
    a lightning game, or something in between that fits a
    tournament's intentions. An overtime period requires a fixed
    number of moves within a predetermined period, e.g. 1 move
    within 60 seconds. A move is finished by pressing the clock.
    - Many variants or other time systems exist, e.g., increasing
    numbers of moves in further overtime periods, penalty points
    for entering further periods, full usage of every overtime
    period, thinking time working like an hour glass, etc.

    6.6 Tournament Rules

    Every tournament uses an announced set of tournament rules.
    They especially specify the used set for the core rules of
    play, the tournament system, tie breakers, the pairing
    method, the winning criteria, compensation methods,
    thinking times, direction, jurisdiction, adjournment
    methods, penalities for being late, etc. Tournament rules
    often deal with details. Not everything can be predicted, so
    a sportsmanlike spirit is mentioned. Finally, it should be
    clear which of several rule sets takes precedence.

    6.7 Tournament Organization

    A regional tournament can be organized by a club. Big events
    can be held at the request of an association or federation,
    who also supervise. A tournament organization is responsible
    for providing a venue and playing material. It must be
    distinguished from the tournament director and his assistant
    directors, who perform the particular tasks of pairing,
    collecting results, and ensuring smooth running. Shared
    power furthermore demands independent referees.

    6.8 Jurisdiction

    Before the start of a tournament valid instances of a
    jurisdiction as well as the persons to be referees must be
    clear. Typically, for a tournament itself there is one
    referee as the first instance and a body of three referees
    as the second instance. For very peculiar cases a federation
    could have a third and final instance. Some tournament rules
    replace the second instance by a single person, called chief
    referee; to avoid confusion he ought not to judge as the
    first instance. Players should respect the referees' tough
    job of mediation or decision; referees should seriously
    enforce the rules.

    6.9 Prizes

    The first places of a tournament invoke major prizes. E.g.
    the first, second, third places might get 3/6, 2/6, 1/6 of
    the available money. In a tournament with many weaker
    players it is a good idea to provide some prizes for all
    other players that win most rounds as well. While prizes can
    be money, books, trophies, etc., one should remember that
    money is most universally accepted and trophies serve the
    media better than the winners. -
    On a related topic, a side event lottery must give equal
    chances to all participants. This is only achieved by using
    one lot for each.

    7 Links

    Most rules information, links, short rules: http://home.snafu.de/jasiek/rules.html

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Robert Jasiek@21:1/5 to All on Wed Aug 12 07:03:08 2020
    Title: Rules FAQ
    Author: Robert Jasiek <jasiek@snafu.de>
    Frequency: monthly
    Last Update: 2017-10-13; First Day: 1999-04-12
    Distribution: rec.games.go
    Copyright: free non-commercial usage for promotion

    0 CONTENTS

    1 Purpose of this Paper
    2 Information for Beginners
    3 Important Concepts
    4 Particular Rules
    5 Troublesome Details
    6 Tournament Rules
    7 Links

    1 PURPOSE OF THIS PAPER

    This paper is a basic reference for important rules terms,
    rules, and tournament rules. Beginners should read
    especially Chapters 2 and 3, players Chapters 3 to 5,
    tournament players and organizers Chapter 6.

    2 INFORMATION FOR BEGINNERS
    2.1 What Must I Know as a Beginner?

    The game is played on a grid board. Typically it has 19x19
    intersections, but 9x9 are also fine. Two players compete.
    The first player uses black stones, the other white.

    The players alternate. A player may play or pass. Playing
    is putting one's own stone on an empty intersection and
    removing any surrounded opposing stones. To avoid
    cycles, a play may not recreate any prior configuration of
    all stones on the board.

    Two successive passes end the game. Then the player with
    more intersections wins. Intersections are his if only his
    stones occupy or surround them.

    2.2 Which Rules do I Need as a Beginner?

    You can play with short rules as in 2.1. Other rules may
    be different, but the game is the same, i. e. strategy,
    tactics, and the score do not change. Extremely rare
    exceptions confirm this rule.

    The winner can be determined by area or by territory.
    Either includes empty intersections surrounded only by own
    stones. While area adds intersections occupied by own
    stones, territory adds opposing prisoners instead.

    All rules, except short rules, have further phases after
    alternation and before scoring. Towards a game end it is
    often clear which stones will be removed. The additional
    phases allow the players to agree on which stones shall be
    removed. Thereby final removals do not require alternation.

    Whether you score by area or by territory or whether you
    remove by alternation or by agreement should mainly depend
    on which rules are used by people you play with.

    2.3 Which Rules Should I Teach?

    One possibility is to use a board with 9x9 intersections,
    short rules as in 2.1, and count each player's score by
    using a finger to scan the board for his intersections.

    3 IMPORTANT CONCEPTS

    While strategy and tactics virtually remain the same,
    concepts vary in different rules. However, the following
    gives a comprehensive overview on standard terms.

    3.1 Stone, String

    The physical device that colours one intersection in a
    play is a STONE. Two intersections of the board are
    ADJACENT if they have a line but no intersection between
    them. Two intersections with either black, white, or no
    stones on them are CONNECTED if they are adjacent or if
    there is a chain of adjacent intersections of their type
    between them. A REGION consists of an intersection and
    any intersections connected to it. A black or white
    region is called a STRING.

    3.2 Surrounded

    An intersection of one colour is SURROUNDED by another
    colour if each leaving path reaches the other colour first
    after the one colour. Hereby it can only be surrounded
    black by white, white by black, empty by black, or empty
    by white. A region can be surrounded. For strings there is
    an alternative notion of no liberty (or breath). A LIBERTY
    of a string is an empty intersection adjacent to it. Thus
    a string is surrounded if and only if it has no liberty.

    3.3 Removal, Suicide

    A removal empties the intersections of surrounded stones
    if there are any. Hereby removal of opposing stones is
    executed first, if necessary. Rules may either require or
    forbid removal of own stones. This is called suicide or no
    suicide. In practice, suicide might be used for so called ko
    fights or in capturing races.

    3.4 Capture, Prisoner

    Rules that score territory call a removal a capture
    because all removed stones are seriously kept as prisoners.

    3.5 Move, Play, Pass

    The players have alternate turns. On each turn a player makes
    a move that is either a play or a pass. A play places one's
    own stone on an empty intersection. It can then include
    removal of surrounded stones, if any. A pass merely continues
    alternation by giving the opponent the next turn.

    3.6 Compensation

    The first move advantage by black can be compensated by
    compensation points (komi) that are added to the white score
    after the game end. Komi can be adjusted by 0.5 to avoid
    ties. Today integer values for komi for 19x19 boards
    typically range between 5 and 7. For 13x13 boards one should
    use 8, for 9x9 boards 6; however, there is no real consensus
    for small board komi values yet. -
    A weaker player (black) can get the right to place an agreed
    number of compensation stones (handicap) before white's first
    play. Rules may allow free or fixed handicap. Free handicap
    does not apply any restriction. Fixed handicap requires
    traditional placement on set intersections.

    3.7 Phases

    Normally, a game consists of the phases alternation,
    agreement, scoring. A game stop is between alternation and
    agreement, the game end is between agreement and scoring,
    and after scoring both players accept the counted score as
    the result. The main part of the game is the alternation
    phase. Special rules are invoked after it. Typically, two
    successive passes in alternation are the game stop and start
    the agreement phase. In it the players may agree on strings
    to be removed. If they agree, then they remove those strings
    from the board; this ends the game. Sometimes they might
    disagree, then no strings are removed but alternation is
    resumed as if the last game stop did not occur.

    3.8 Recreation

    The position is the pattern of black and white stones on the
    board. Without extra rule a position might be repeated
    infinitely. The easiest rule to prohibit this says: A play
    may not recreate a position. This refers to positions after
    completion of plays, i.e. after possible removals. The rule
    is called "superko". -
    Some rules use concepts different from superko. They combine
    a "2-play rule" with a "long cycle rule". The first says:
    Two successive plays may not recreate a position. The second
    says: If a position is recreated after more than two moves,
    then the game ends either immediately or, as a variant, as
    soon as the players agree, with the result "without result".
    In practice the 2-play rule is sufficient for almost all
    cases. It handles the relevant standard pattern of two
    adjacent intersections. For superko this is just a special
    application.

    3.9 Scoring

    The score is the result after the game end as defined by
    the rules. There are two different scoring methods: area
    scoring and territory scoring. Rules use one of them. Both
    give the same result in almost all cases and both evaluate
    the difference of the black and the white scores. A player's
    AREA score is the sum of intersections with own stones and
    of empty intersections surrounded only by own stones. Simply
    speaking, a player's TERRITORY score is the sum of empty
    intersections surrounded only by own stones and of prisoners
    of opposing colour. With both scoring methods empty
    intersections that are not surrounded by either black or
    white are neutral.

    3.10 Counting

    A score must be determined by some mechanical procedure in
    practice; this is called counting. There are various methods.
    Some rules prescribe one. A possible method is to use one's
    finger to count point by point. Other methods rearrange a lot
    of stones on the board.

    4 PARTICULAR RULES

    Rules vary extremely. However, in practice they often give
    the same result.

    4.1 Short Rules

    Examples of short rules are the Simple Rules or the
    Tromp-Taylor rules. They have no game stop and no agreement.
    Both are superfluous since necessary removals may already be
    performed in the alternation. Two successive passes end the
    game that is scored then. Short rules use area scoring,
    superko, and suicide. Further settings are left for
    tournament rules.

    4.2 American Rules

    These are used by the American Go Association. They use
    situational superko, no suicide, and 7.5 komi. They permit
    free or fixed handicap. Their most remarkable feature is to
    allow one of area scoring or territory scoring. Herefore
    pass stones (one prisoner compensates each pass) and white
    moving last always ensure the same result, regardless of the
    applied scoring method.

    4.3 Chinese Rules

    These are used in continental China and sometimes in other
    countries. Area scoring and no suicide are used.

    4.3.1 Official Chinese Rules

    In practice, ko rules roughly amount to a 2-play rule and a
    long cycle rule. The mentioned superko is overridden. The
    counting is a sophisticated half counting, where empty
    intersections and then after rearrangements stones of one
    colour are added to be compared with half the non-neutral
    intersections. The komi as a half komi is 3.75. In full
    counting, counts and komi would be twice as big.

    4.3.2 Simplified Chinese Rules

    Positional superko is used. A counting method is not
    prescribed. The full komi should be 7.5.

    4.4 Japanese Rules

    The differences mainly affect handling of late game phases
    but often do not alter scores. Japanese rules use some
    traditional territory scoring that attempts to exclude so
    called sekis. No suicide applies. The core of the ko rules
    is a 2-play rule and a long cycle rule. Typically, komi is
    6.5. Fixed handicap should be used. The counting is a
    sophisticated rearrangement of empty intersections and
    filling-in of prisoners.

    4.4.1 Game Finishing Process

    A game finishes with the following process: 1) So called
    dame (neutral points) and defensive moves (necessary
    connections etc. due to occupied dame) are filled.
    2) The hypothetical analysis, which presumes perfect play,
    determines so called life or death of each string and the
    scoring intersections. 3) Without making any approach moves,
    dead stones are removed from scoring intersections and added
    to the prisoners. 4) The score is counted. (2) and (3) do not
    allow to play out life and death since actually filling
    intersections costs points in Japanese rules.

    4.4.2 Official Japanese Rules

    There are the Japanese 1989 Rules, which are used in Japan
    and elsewhere, and the World Amateur Go Championships Rules,
    which are used in some particular tournaments. Korean rules
    are similar to Japanese rules but have a very different text
    and differ in rare positions. Official Japanese rules are
    very incomplete and have messy late game phases. E.g., the
    Japanese 1989 Rules allow filling of dame during alternation,
    after it, or both and have a so called ko-pass-rule for the
    hypothetical analysis. Now professional Japanese rules are
    explained precisely by a rules expert's interpretation called
    "the Japanese 2003 Rules".

    4.4.3 Simplified Japanese Rules

    As a recent invention, they are not used yet. They are
    complete and have clear late game phases. Filling of dame is
    done during alternation.

    4.4.4 Verbal Japanese Rules

    They are used for informal games in many countries and
    undefined, except that the game finishing process is used.
    In a tournament without any official rules of play, disputes
    are not solved due to the rules but with a referee.

    4.5 Ing Rules

    Ing rules use area scoring, suicide, 8 komi with black
    winning ties, and free handicap.

    4.5.1 Official Ing Rules

    The ko rules are a mess but somehow resemble superko.
    Details could fill books. The late game phases are specified
    insufficiently. The peculiar counting method requires 180
    stones of each colour throughout the game, fills any stones
    on the board after the game end, and leaves exactly one
    empty intersection, which determines the winner. The
    official rules are used in professional Taiwanese and some
    sponsored tournaments. Taiwanese amateurs have their own
    rules.

    4.5.2 Simplified Ing Rules

    Positional superko is used. A counting method is not
    prescribed. The late game phases are specified clearly. The
    simplified rules are used in EGF tournaments that are said
    to use Ing rules.

    4.6 New Zealand Rules

    Area scoring, suicide, situational superko, 7 komi, and free
    handicap are used.

    4.7 Go Server Rules

    Every go server has its own and often complicated rules, if
    any, so they cannot be given in detail here. Concerning
    "IGS rules", territory scoring, no suicide, a 2-play rule,
    fixed handicap, three game stopping passes, and captures in
    an agreement phase are used. Details about agreements and
    long cycles are not specified and lead to adjourned games in
    case of doubt. Komi is suggested but may be altered. Counting
    is automatic. "Yahoo" has territory scoring, no suicide, a
    2-play rule, two game stopping passes; long cycles and
    disagreements are not handled properly. On "email servers"
    players must agree on any rules. -
    Typically territory scoring on a go server means that neither
    points in any sekis are excluded nor pass stones are used.
    Thus while the Japanese seki exception is abandoned,
    disagreements about removals may lead to games without result
    since playing out can cost points.

    4.8 International Rules

    The international mailing list go-rules has proposed
    international rules, however, none are adopted yet. The core
    rules of play shall be clear, complete, and correct.
    Currently alternative texts are offered for suicide,
    recreation, and scoring. Especially unification of scoring
    methods is advocated.

    4.9 EGF Rules

    The EGF uses the Simplified Ing Rules with 8 komi (black
    wins ties) in Ing sponsored tournaments and the Nihon Kiin
    1989 Rules with 6.5 komi in Japanese/Korean sponsored
    tournaments. If significantly the European Go Championship
    has both kinds of sponsors, then boards 1-16 use the Nihon
    Kiin 1989 Rules and boards 17+ the Simplified Ing Rules.
    However, time settings depend on ranks.

    5 TROUBLESOME DETAILS

    5.1 Colour Choice

    In even games typically the colours are randomly chosen. In
    handicap games black receives the handicap stones. -
    A manual method for randomly choosing colours is called
    nigiri. The older player hides a number of white stones
    taken from the bowl, the opponent takes one or two black
    stones to guess the parity, and the parity of the number of
    white stones is revealed. If the opponent guesses right,
    then he takes black, else he takes white.

    5.2 Pass Stones

    Some rules use pass stones. A passing player adds one own
    stone to the prisoners. As a consequence, captures before
    the game end can be resolved in alternation without any loss
    because any not answered approach move is compensated by one
    pass stone. With traditional territory scoring that uses no
    pass stones definition problems arise due to this missing
    option. Modern territory scoring or equivalence scoring use
    pass stones.

    5.3 Equivalence

    Area scoring and territory scoring are close because either
    intersections occupied by own stones or opposing prisoners
    are used. Essentially, every prisoner is a stone removed
    from some intersection. For area it scores one point less
    for the stone's player while for territory it scores one
    point more for his opponent. This is equal. Exact equality
    for the entire game must also consider passes by using pass
    stones and an equal number of moves by requiring white to
    pass last. This is done by equivalence scoring.

    5.4 Meaning of Agreement Removals

    Removals in an agreement phase under area scoring are fair
    because they may as well occur in alternation. Removing a
    stone due to agreement includes its then empty intersection
    and all adjacent empty intersections in the score. Removing
    a stone by means of alternation includes its then empty
    intersection and all adjacent newly occupied intersections
    in the score. -
    With traditional territory scoring this is not possible
    since stones on the board do not score. Thus final captures
    must occur after the game end due to attempted definitions
    in the rules.

    5.5 Practical Scoring Differences

    Since area scoring and modern territory scoring using pass
    stones are equal, correct play is the same for both. Apart
    from Japanese rules exceptions like not scoring empty
    intersections especially in asymmetrical coexistences or
    like a pass-for-ko-rule, traditional territory scoring can
    make a different winner in practically ca. every 10000th
    even game. This is so rare because of a parity feature
    combined with a scarcely odd number of intersections that
    are in coexistences but do not score for area at the game
    end. With area scoring a komi change from 1.5, 3.5, 5.5, ...
    to 2.5, 4.5, 6.5, ... almost always would not change the
    winner. So altough occupying the last empty intersections
    that would otherwise not score just before a game stop gains
    one point each, alternately doing so leaves a total
    advantage of at most one point. Due to the parity feature
    the player to get it is predetermined when this occupation
    starts. More importantly, one final ko is worth 1 point under
    traditional territory scoring but 2 or rarely 4 points under
    area scoring. Rare one-sided points in coexistences provide
    only area. Other practical differences are even rarer. Cute
    players include the stones in their endgame value counts
    during the middle of an area scoring game.

    5.6 Stone Scoring

    In ancient times stone scoring was popular. Only stones on
    the board are scored. Thus empty intersections surrounded by
    own stones are filled until necessary so called eyes remain.
    Disconnected stones require more eyes in total, the so
    called group tax.

    5.7 Old Ing Scoring

    Old Ing rules allowed fractional scores by assigning points
    to neutral empty regions due to the percentage of black and
    white stones surrounding every region.

    5.8 Primitive Rules

    They do not have passes. Alternation ends when a player
    loses due to no legal play. Games can be extremely long and
    include special strategies, so called pass fights. Primitive
    rules (also called no pass rules or Conway rules) can be
    useful in mathematics.

    5.9 Tradition

    Historically, exceptions arose, which some like as such
    especially together with Japanese style rules. So called
    sekis are excluded from the score. Special positions, termed
    precedents, have special rules. Modern Japanese rules have
    generalized a lot of them by a pass-for-ko-rule. After the
    game stop or after the game end and particularly in
    hypothetical play a stone captured in a possible 2-play cycle
    may not be recaptured unless before a pass is made that
    specifies the particular 2-play cycle.

    5.10 Positional / Situational Superko

    Positional superko prohibits a play that recreates a position.
    Situational superko refers to the situation, i.e. to the
    position together with the right to move. So a play is
    prohibited if it recreates a position while the same player
    has the right to move. In practice the differences are
    extremely rare.

    5.11 Handicap Recompensation

    With area scoring handicap stones beyond the first provide
    a potential extra area of one point per handicap stone. Komi
    for white may consider this. Recompensation, H-1 points for H
    handicap stones, is virtually only used together with
    American rules.

    5.12 Mathematics

    Go is a complete information game, i.e. at every move each
    player knows the entire game situation. Hence theoretically
    an algorithm could determine perfect play. However, due to
    the complexity of the game with N intersections, for which
    it is provably impossible to devise a polynomial time
    solution, perfect play or ideal komi are unknown. What one
    does know is that in a game without komi the first player wins
    or ties and that perfect play is independent of set komi. Many
    other propositions have been discovered, some of which
    describe the relation between area and territory scoring, solve
    tiny endgame positions or cyclical behaviour. -
    Go is a very complex game! According to John Tromp, the number
    of legal positions is:

    208168199381979984699478633344862770286522453884530548425 639456820927419612738015378525648451698519643907259916015 628128546089888314427129715319317557736620397247064840935

    For positional superko, no passes, and no resignation, the
    number of possible games is smaller than N**L(N) because L(N)
    also restricts the maximal number of moves per game and there
    are at most N possible intersections per move. (The sign ** is
    a text file notation for "to the power".) -
    Extremely modest estimates look like 10**N, which is based on
    an assumption of 10 reasonable intersections per move. A
    popular estimate for 19x19 go is 10**761, which must have
    originated from a typo and should be 10**361, if at all...
    These types of estimates are so popular because humans cannot
    even imagine the suggested number of atoms in the universe,
    10**80. For comparison, 3**361 is ca. 10**172.

    6 TOURNAMENT RULES

    6.1 Special Game Ends

    If the score considering the komi is zero, then the game is a
    tie and should be treated as 0.5 won games for each. Special
    rules or undue behaviour like sincere lateness might result
    in a referee declaring a win by forfeit, 0:0, or 1:1,
    whichever is most appropriate.

    6.2 Tournament Systems

    A tournament might consist of several stages, of which each
    has a seed and a system. A seed appropriately restricts
    participation, e.g. due to qualification. The most important
    systems are match, league, knockout, Swiss, McMahon. There
    are many others and hybrids. A system must fit the aims of a
    tournament. A sufficient number of rounds, a proper seed,
    and colour variation ensure a fair determination of the best
    player. -
    A match takes place between two players that either play a
    set number of games to see who wins more or a maximal number
    of games to see who wins a predetermined number of games
    first. In a league a small, usually even number of players
    performs a round-robin tournament, so that in each round all
    players play and every two players play against each other,
    one game e.g. A knockout preferably starts with a number of
    players that is a power of two. Losing players are eliminated,
    winning players continue until the winner remains. -
    In a Swiss system before each round each player's achieved
    number of wins is used to pair players with equal numbers as
    far as possible. So all players play all rounds and some time
    the best player will emerge. However, with greatly varying
    strengths too many rounds would be needed. So Swiss is only
    useful for particular events or handicap tournaments.
    McMahon is the refinement of Swiss. Before the start of the
    tournament all players are classified in rank groups, with
    ranks R from 0 to T. This means that one assumes a preceding
    Swiss tournament where every player has already won R games.
    Then in the McMahon tournament the strongest players, who
    deserve the rank T, compete for the top places. In practice,
    one uses a bar B, that is 1 or 2 ranks below T, so that all
    ranks above B are contracted to B and also players slightly
    weaker than the top players get their chance. All players in
    a McMahon play roughly equal opponents; if they win or lose,
    then the opponents will be stronger or weaker.

    6.3 Tie Breakers

    Tie breakers can refine pairings or results. Typically the
    first criterion is the number of wins (or McMahon points);
    all further criteria, if any, are tie breakers. They attempt
    a refinement where a low number of rounds and a tournament
    system do not guarantee sufficient distinction between
    players' achievements. However, they must be applied with
    care since they are only marginally better than coin tossing.
    Examples of tie breakers are direct comparison, which
    acknowledges the winner of a game between two players in
    question, and SOS, which is the Sum of Opponents' Scores. -
    The possible degree of quality of tie breakers is subject to
    discussion. It depends on tournament system, whether only the
    top or all players shall be distinguished, and other factors.
    An alternative to the usage of tie breakers for the final
    results ordering is issuing shared places for all players
    with the same number of wins (or McMahon points). - One must
    fairly assign tie breaker points for opponents missing in
    some round; enforcing participation is preferable especially
    for top players.

    6.4 Pairing

    Pairings must be fair, precise, and consider prior
    achievements during a tournament. One should consider colour
    balance and no pair twice, one might also aim at avoiding a
    pair of players from the same club or country, depending on
    a tournament's intentions. Pairings might be done manually
    in small tournaments; for most tournaments pairing programs
    should be used. These can create fair pairings convincingly,
    some even watch global balance.

    6.5 Thinking Times

    The age of killing each other by greater endurance has gone.
    Clocks are used to count each player's remaining thinking
    time. Typically, every game has a basic time and overtime
    periods. Exceeding a time limit loses a game. Basic time
    might be 9 hours for a professional top game, 10 minutes for
    a lightning game, or something in between that fits a
    tournament's intentions. An overtime period requires a fixed
    number of moves within a predetermined period, e.g. 1 move
    within 60 seconds. A move is finished by pressing the clock.
    - Many variants or other time systems exist, e.g., increasing
    numbers of moves in further overtime periods, penalty points
    for entering further periods, full usage of every overtime
    period, thinking time working like an hour glass, etc.

    6.6 Tournament Rules

    Every tournament uses an announced set of tournament rules.
    They especially specify the used set for the core rules of
    play, the tournament system, tie breakers, the pairing
    method, the winning criteria, compensation methods,
    thinking times, direction, jurisdiction, adjournment
    methods, penalities for being late, etc. Tournament rules
    often deal with details. Not everything can be predicted, so
    a sportsmanlike spirit is mentioned. Finally, it should be
    clear which of several rule sets takes precedence.

    6.7 Tournament Organization

    A regional tournament can be organized by a club. Big events
    can be held at the request of an association or federation,
    who also supervise. A tournament organization is responsible
    for providing a venue and playing material. It must be
    distinguished from the tournament director and his assistant
    directors, who perform the particular tasks of pairing,
    collecting results, and ensuring smooth running. Shared
    power furthermore demands independent referees.

    6.8 Jurisdiction

    Before the start of a tournament valid instances of a
    jurisdiction as well as the persons to be referees must be
    clear. Typically, for a tournament itself there is one
    referee as the first instance and a body of three referees
    as the second instance. For very peculiar cases a federation
    could have a third and final instance. Some tournament rules
    replace the second instance by a single person, called chief
    referee; to avoid confusion he ought not to judge as the
    first instance. Players should respect the referees' tough
    job of mediation or decision; referees should seriously
    enforce the rules.

    6.9 Prizes

    The first places of a tournament invoke major prizes. E.g.
    the first, second, third places might get 3/6, 2/6, 1/6 of
    the available money. In a tournament with many weaker
    players it is a good idea to provide some prizes for all
    other players that win most rounds as well. While prizes can
    be money, books, trophies, etc., one should remember that
    money is most universally accepted and trophies serve the
    media better than the winners. -
    On a related topic, a side event lottery must give equal
    chances to all participants. This is only achieved by using
    one lot for each.

    7 Links

    Most rules information, links, short rules: http://home.snafu.de/jasiek/rules.html

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Robert Jasiek@21:1/5 to All on Sun Sep 13 07:00:35 2020
    Title: Rules FAQ
    Author: Robert Jasiek <jasiek@snafu.de>
    Frequency: monthly
    Last Update: 2017-10-13; First Day: 1999-04-12
    Distribution: rec.games.go
    Copyright: free non-commercial usage for promotion

    0 CONTENTS

    1 Purpose of this Paper
    2 Information for Beginners
    3 Important Concepts
    4 Particular Rules
    5 Troublesome Details
    6 Tournament Rules
    7 Links

    1 PURPOSE OF THIS PAPER

    This paper is a basic reference for important rules terms,
    rules, and tournament rules. Beginners should read
    especially Chapters 2 and 3, players Chapters 3 to 5,
    tournament players and organizers Chapter 6.

    2 INFORMATION FOR BEGINNERS
    2.1 What Must I Know as a Beginner?

    The game is played on a grid board. Typically it has 19x19
    intersections, but 9x9 are also fine. Two players compete.
    The first player uses black stones, the other white.

    The players alternate. A player may play or pass. Playing
    is putting one's own stone on an empty intersection and
    removing any surrounded opposing stones. To avoid
    cycles, a play may not recreate any prior configuration of
    all stones on the board.

    Two successive passes end the game. Then the player with
    more intersections wins. Intersections are his if only his
    stones occupy or surround them.

    2.2 Which Rules do I Need as a Beginner?

    You can play with short rules as in 2.1. Other rules may
    be different, but the game is the same, i. e. strategy,
    tactics, and the score do not change. Extremely rare
    exceptions confirm this rule.

    The winner can be determined by area or by territory.
    Either includes empty intersections surrounded only by own
    stones. While area adds intersections occupied by own
    stones, territory adds opposing prisoners instead.

    All rules, except short rules, have further phases after
    alternation and before scoring. Towards a game end it is
    often clear which stones will be removed. The additional
    phases allow the players to agree on which stones shall be
    removed. Thereby final removals do not require alternation.

    Whether you score by area or by territory or whether you
    remove by alternation or by agreement should mainly depend
    on which rules are used by people you play with.

    2.3 Which Rules Should I Teach?

    One possibility is to use a board with 9x9 intersections,
    short rules as in 2.1, and count each player's score by
    using a finger to scan the board for his intersections.

    3 IMPORTANT CONCEPTS

    While strategy and tactics virtually remain the same,
    concepts vary in different rules. However, the following
    gives a comprehensive overview on standard terms.

    3.1 Stone, String

    The physical device that colours one intersection in a
    play is a STONE. Two intersections of the board are
    ADJACENT if they have a line but no intersection between
    them. Two intersections with either black, white, or no
    stones on them are CONNECTED if they are adjacent or if
    there is a chain of adjacent intersections of their type
    between them. A REGION consists of an intersection and
    any intersections connected to it. A black or white
    region is called a STRING.

    3.2 Surrounded

    An intersection of one colour is SURROUNDED by another
    colour if each leaving path reaches the other colour first
    after the one colour. Hereby it can only be surrounded
    black by white, white by black, empty by black, or empty
    by white. A region can be surrounded. For strings there is
    an alternative notion of no liberty (or breath). A LIBERTY
    of a string is an empty intersection adjacent to it. Thus
    a string is surrounded if and only if it has no liberty.

    3.3 Removal, Suicide

    A removal empties the intersections of surrounded stones
    if there are any. Hereby removal of opposing stones is
    executed first, if necessary. Rules may either require or
    forbid removal of own stones. This is called suicide or no
    suicide. In practice, suicide might be used for so called ko
    fights or in capturing races.

    3.4 Capture, Prisoner

    Rules that score territory call a removal a capture
    because all removed stones are seriously kept as prisoners.

    3.5 Move, Play, Pass

    The players have alternate turns. On each turn a player makes
    a move that is either a play or a pass. A play places one's
    own stone on an empty intersection. It can then include
    removal of surrounded stones, if any. A pass merely continues
    alternation by giving the opponent the next turn.

    3.6 Compensation

    The first move advantage by black can be compensated by
    compensation points (komi) that are added to the white score
    after the game end. Komi can be adjusted by 0.5 to avoid
    ties. Today integer values for komi for 19x19 boards
    typically range between 5 and 7. For 13x13 boards one should
    use 8, for 9x9 boards 6; however, there is no real consensus
    for small board komi values yet. -
    A weaker player (black) can get the right to place an agreed
    number of compensation stones (handicap) before white's first
    play. Rules may allow free or fixed handicap. Free handicap
    does not apply any restriction. Fixed handicap requires
    traditional placement on set intersections.

    3.7 Phases

    Normally, a game consists of the phases alternation,
    agreement, scoring. A game stop is between alternation and
    agreement, the game end is between agreement and scoring,
    and after scoring both players accept the counted score as
    the result. The main part of the game is the alternation
    phase. Special rules are invoked after it. Typically, two
    successive passes in alternation are the game stop and start
    the agreement phase. In it the players may agree on strings
    to be removed. If they agree, then they remove those strings
    from the board; this ends the game. Sometimes they might
    disagree, then no strings are removed but alternation is
    resumed as if the last game stop did not occur.

    3.8 Recreation

    The position is the pattern of black and white stones on the
    board. Without extra rule a position might be repeated
    infinitely. The easiest rule to prohibit this says: A play
    may not recreate a position. This refers to positions after
    completion of plays, i.e. after possible removals. The rule
    is called "superko". -
    Some rules use concepts different from superko. They combine
    a "2-play rule" with a "long cycle rule". The first says:
    Two successive plays may not recreate a position. The second
    says: If a position is recreated after more than two moves,
    then the game ends either immediately or, as a variant, as
    soon as the players agree, with the result "without result".
    In practice the 2-play rule is sufficient for almost all
    cases. It handles the relevant standard pattern of two
    adjacent intersections. For superko this is just a special
    application.

    3.9 Scoring

    The score is the result after the game end as defined by
    the rules. There are two different scoring methods: area
    scoring and territory scoring. Rules use one of them. Both
    give the same result in almost all cases and both evaluate
    the difference of the black and the white scores. A player's
    AREA score is the sum of intersections with own stones and
    of empty intersections surrounded only by own stones. Simply
    speaking, a player's TERRITORY score is the sum of empty
    intersections surrounded only by own stones and of prisoners
    of opposing colour. With both scoring methods empty
    intersections that are not surrounded by either black or
    white are neutral.

    3.10 Counting

    A score must be determined by some mechanical procedure in
    practice; this is called counting. There are various methods.
    Some rules prescribe one. A possible method is to use one's
    finger to count point by point. Other methods rearrange a lot
    of stones on the board.

    4 PARTICULAR RULES

    Rules vary extremely. However, in practice they often give
    the same result.

    4.1 Short Rules

    Examples of short rules are the Simple Rules or the
    Tromp-Taylor rules. They have no game stop and no agreement.
    Both are superfluous since necessary removals may already be
    performed in the alternation. Two successive passes end the
    game that is scored then. Short rules use area scoring,
    superko, and suicide. Further settings are left for
    tournament rules.

    4.2 American Rules

    These are used by the American Go Association. They use
    situational superko, no suicide, and 7.5 komi. They permit
    free or fixed handicap. Their most remarkable feature is to
    allow one of area scoring or territory scoring. Herefore
    pass stones (one prisoner compensates each pass) and white
    moving last always ensure the same result, regardless of the
    applied scoring method.

    4.3 Chinese Rules

    These are used in continental China and sometimes in other
    countries. Area scoring and no suicide are used.

    4.3.1 Official Chinese Rules

    In practice, ko rules roughly amount to a 2-play rule and a
    long cycle rule. The mentioned superko is overridden. The
    counting is a sophisticated half counting, where empty
    intersections and then after rearrangements stones of one
    colour are added to be compared with half the non-neutral
    intersections. The komi as a half komi is 3.75. In full
    counting, counts and komi would be twice as big.

    4.3.2 Simplified Chinese Rules

    Positional superko is used. A counting method is not
    prescribed. The full komi should be 7.5.

    4.4 Japanese Rules

    The differences mainly affect handling of late game phases
    but often do not alter scores. Japanese rules use some
    traditional territory scoring that attempts to exclude so
    called sekis. No suicide applies. The core of the ko rules
    is a 2-play rule and a long cycle rule. Typically, komi is
    6.5. Fixed handicap should be used. The counting is a
    sophisticated rearrangement of empty intersections and
    filling-in of prisoners.

    4.4.1 Game Finishing Process

    A game finishes with the following process: 1) So called
    dame (neutral points) and defensive moves (necessary
    connections etc. due to occupied dame) are filled.
    2) The hypothetical analysis, which presumes perfect play,
    determines so called life or death of each string and the
    scoring intersections. 3) Without making any approach moves,
    dead stones are removed from scoring intersections and added
    to the prisoners. 4) The score is counted. (2) and (3) do not
    allow to play out life and death since actually filling
    intersections costs points in Japanese rules.

    4.4.2 Official Japanese Rules

    There are the Japanese 1989 Rules, which are used in Japan
    and elsewhere, and the World Amateur Go Championships Rules,
    which are used in some particular tournaments. Korean rules
    are similar to Japanese rules but have a very different text
    and differ in rare positions. Official Japanese rules are
    very incomplete and have messy late game phases. E.g., the
    Japanese 1989 Rules allow filling of dame during alternation,
    after it, or both and have a so called ko-pass-rule for the
    hypothetical analysis. Now professional Japanese rules are
    explained precisely by a rules expert's interpretation called
    "the Japanese 2003 Rules".

    4.4.3 Simplified Japanese Rules

    As a recent invention, they are not used yet. They are
    complete and have clear late game phases. Filling of dame is
    done during alternation.

    4.4.4 Verbal Japanese Rules

    They are used for informal games in many countries and
    undefined, except that the game finishing process is used.
    In a tournament without any official rules of play, disputes
    are not solved due to the rules but with a referee.

    4.5 Ing Rules

    Ing rules use area scoring, suicide, 8 komi with black
    winning ties, and free handicap.

    4.5.1 Official Ing Rules

    The ko rules are a mess but somehow resemble superko.
    Details could fill books. The late game phases are specified
    insufficiently. The peculiar counting method requires 180
    stones of each colour throughout the game, fills any stones
    on the board after the game end, and leaves exactly one
    empty intersection, which determines the winner. The
    official rules are used in professional Taiwanese and some
    sponsored tournaments. Taiwanese amateurs have their own
    rules.

    4.5.2 Simplified Ing Rules

    Positional superko is used. A counting method is not
    prescribed. The late game phases are specified clearly. The
    simplified rules are used in EGF tournaments that are said
    to use Ing rules.

    4.6 New Zealand Rules

    Area scoring, suicide, situational superko, 7 komi, and free
    handicap are used.

    4.7 Go Server Rules

    Every go server has its own and often complicated rules, if
    any, so they cannot be given in detail here. Concerning
    "IGS rules", territory scoring, no suicide, a 2-play rule,
    fixed handicap, three game stopping passes, and captures in
    an agreement phase are used. Details about agreements and
    long cycles are not specified and lead to adjourned games in
    case of doubt. Komi is suggested but may be altered. Counting
    is automatic. "Yahoo" has territory scoring, no suicide, a
    2-play rule, two game stopping passes; long cycles and
    disagreements are not handled properly. On "email servers"
    players must agree on any rules. -
    Typically territory scoring on a go server means that neither
    points in any sekis are excluded nor pass stones are used.
    Thus while the Japanese seki exception is abandoned,
    disagreements about removals may lead to games without result
    since playing out can cost points.

    4.8 International Rules

    The international mailing list go-rules has proposed
    international rules, however, none are adopted yet. The core
    rules of play shall be clear, complete, and correct.
    Currently alternative texts are offered for suicide,
    recreation, and scoring. Especially unification of scoring
    methods is advocated.

    4.9 EGF Rules

    The EGF uses the Simplified Ing Rules with 8 komi (black
    wins ties) in Ing sponsored tournaments and the Nihon Kiin
    1989 Rules with 6.5 komi in Japanese/Korean sponsored
    tournaments. If significantly the European Go Championship
    has both kinds of sponsors, then boards 1-16 use the Nihon
    Kiin 1989 Rules and boards 17+ the Simplified Ing Rules.
    However, time settings depend on ranks.

    5 TROUBLESOME DETAILS

    5.1 Colour Choice

    In even games typically the colours are randomly chosen. In
    handicap games black receives the handicap stones. -
    A manual method for randomly choosing colours is called
    nigiri. The older player hides a number of white stones
    taken from the bowl, the opponent takes one or two black
    stones to guess the parity, and the parity of the number of
    white stones is revealed. If the opponent guesses right,
    then he takes black, else he takes white.

    5.2 Pass Stones

    Some rules use pass stones. A passing player adds one own
    stone to the prisoners. As a consequence, captures before
    the game end can be resolved in alternation without any loss
    because any not answered approach move is compensated by one
    pass stone. With traditional territory scoring that uses no
    pass stones definition problems arise due to this missing
    option. Modern territory scoring or equivalence scoring use
    pass stones.

    5.3 Equivalence

    Area scoring and territory scoring are close because either
    intersections occupied by own stones or opposing prisoners
    are used. Essentially, every prisoner is a stone removed
    from some intersection. For area it scores one point less
    for the stone's player while for territory it scores one
    point more for his opponent. This is equal. Exact equality
    for the entire game must also consider passes by using pass
    stones and an equal number of moves by requiring white to
    pass last. This is done by equivalence scoring.

    5.4 Meaning of Agreement Removals

    Removals in an agreement phase under area scoring are fair
    because they may as well occur in alternation. Removing a
    stone due to agreement includes its then empty intersection
    and all adjacent empty intersections in the score. Removing
    a stone by means of alternation includes its then empty
    intersection and all adjacent newly occupied intersections
    in the score. -
    With traditional territory scoring this is not possible
    since stones on the board do not score. Thus final captures
    must occur after the game end due to attempted definitions
    in the rules.

    5.5 Practical Scoring Differences

    Since area scoring and modern territory scoring using pass
    stones are equal, correct play is the same for both. Apart
    from Japanese rules exceptions like not scoring empty
    intersections especially in asymmetrical coexistences or
    like a pass-for-ko-rule, traditional territory scoring can
    make a different winner in practically ca. every 10000th
    even game. This is so rare because of a parity feature
    combined with a scarcely odd number of intersections that
    are in coexistences but do not score for area at the game
    end. With area scoring a komi change from 1.5, 3.5, 5.5, ...
    to 2.5, 4.5, 6.5, ... almost always would not change the
    winner. So altough occupying the last empty intersections
    that would otherwise not score just before a game stop gains
    one point each, alternately doing so leaves a total
    advantage of at most one point. Due to the parity feature
    the player to get it is predetermined when this occupation
    starts. More importantly, one final ko is worth 1 point under
    traditional territory scoring but 2 or rarely 4 points under
    area scoring. Rare one-sided points in coexistences provide
    only area. Other practical differences are even rarer. Cute
    players include the stones in their endgame value counts
    during the middle of an area scoring game.

    5.6 Stone Scoring

    In ancient times stone scoring was popular. Only stones on
    the board are scored. Thus empty intersections surrounded by
    own stones are filled until necessary so called eyes remain.
    Disconnected stones require more eyes in total, the so
    called group tax.

    5.7 Old Ing Scoring

    Old Ing rules allowed fractional scores by assigning points
    to neutral empty regions due to the percentage of black and
    white stones surrounding every region.

    5.8 Primitive Rules

    They do not have passes. Alternation ends when a player
    loses due to no legal play. Games can be extremely long and
    include special strategies, so called pass fights. Primitive
    rules (also called no pass rules or Conway rules) can be
    useful in mathematics.

    5.9 Tradition

    Historically, exceptions arose, which some like as such
    especially together with Japanese style rules. So called
    sekis are excluded from the score. Special positions, termed
    precedents, have special rules. Modern Japanese rules have
    generalized a lot of them by a pass-for-ko-rule. After the
    game stop or after the game end and particularly in
    hypothetical play a stone captured in a possible 2-play cycle
    may not be recaptured unless before a pass is made that
    specifies the particular 2-play cycle.

    5.10 Positional / Situational Superko

    Positional superko prohibits a play that recreates a position.
    Situational superko refers to the situation, i.e. to the
    position together with the right to move. So a play is
    prohibited if it recreates a position while the same player
    has the right to move. In practice the differences are
    extremely rare.

    5.11 Handicap Recompensation

    With area scoring handicap stones beyond the first provide
    a potential extra area of one point per handicap stone. Komi
    for white may consider this. Recompensation, H-1 points for H
    handicap stones, is virtually only used together with
    American rules.

    5.12 Mathematics

    Go is a complete information game, i.e. at every move each
    player knows the entire game situation. Hence theoretically
    an algorithm could determine perfect play. However, due to
    the complexity of the game with N intersections, for which
    it is provably impossible to devise a polynomial time
    solution, perfect play or ideal komi are unknown. What one
    does know is that in a game without komi the first player wins
    or ties and that perfect play is independent of set komi. Many
    other propositions have been discovered, some of which
    describe the relation between area and territory scoring, solve
    tiny endgame positions or cyclical behaviour. -
    Go is a very complex game! According to John Tromp, the number
    of legal positions is:

    208168199381979984699478633344862770286522453884530548425 639456820927419612738015378525648451698519643907259916015 628128546089888314427129715319317557736620397247064840935

    For positional superko, no passes, and no resignation, the
    number of possible games is smaller than N**L(N) because L(N)
    also restricts the maximal number of moves per game and there
    are at most N possible intersections per move. (The sign ** is
    a text file notation for "to the power".) -
    Extremely modest estimates look like 10**N, which is based on
    an assumption of 10 reasonable intersections per move. A
    popular estimate for 19x19 go is 10**761, which must have
    originated from a typo and should be 10**361, if at all...
    These types of estimates are so popular because humans cannot
    even imagine the suggested number of atoms in the universe,
    10**80. For comparison, 3**361 is ca. 10**172.

    6 TOURNAMENT RULES

    6.1 Special Game Ends

    If the score considering the komi is zero, then the game is a
    tie and should be treated as 0.5 won games for each. Special
    rules or undue behaviour like sincere lateness might result
    in a referee declaring a win by forfeit, 0:0, or 1:1,
    whichever is most appropriate.

    6.2 Tournament Systems

    A tournament might consist of several stages, of which each
    has a seed and a system. A seed appropriately restricts
    participation, e.g. due to qualification. The most important
    systems are match, league, knockout, Swiss, McMahon. There
    are many others and hybrids. A system must fit the aims of a
    tournament. A sufficient number of rounds, a proper seed,
    and colour variation ensure a fair determination of the best
    player. -
    A match takes place between two players that either play a
    set number of games to see who wins more or a maximal number
    of games to see who wins a predetermined number of games
    first. In a league a small, usually even number of players
    performs a round-robin tournament, so that in each round all
    players play and every two players play against each other,
    one game e.g. A knockout preferably starts with a number of
    players that is a power of two. Losing players are eliminated,
    winning players continue until the winner remains. -
    In a Swiss system before each round each player's achieved
    number of wins is used to pair players with equal numbers as
    far as possible. So all players play all rounds and some time
    the best player will emerge. However, with greatly varying
    strengths too many rounds would be needed. So Swiss is only
    useful for particular events or handicap tournaments.
    McMahon is the refinement of Swiss. Before the start of the
    tournament all players are classified in rank groups, with
    ranks R from 0 to T. This means that one assumes a preceding
    Swiss tournament where every player has already won R games.
    Then in the McMahon tournament the strongest players, who
    deserve the rank T, compete for the top places. In practice,
    one uses a bar B, that is 1 or 2 ranks below T, so that all
    ranks above B are contracted to B and also players slightly
    weaker than the top players get their chance. All players in
    a McMahon play roughly equal opponents; if they win or lose,
    then the opponents will be stronger or weaker.

    6.3 Tie Breakers

    Tie breakers can refine pairings or results. Typically the
    first criterion is the number of wins (or McMahon points);
    all further criteria, if any, are tie breakers. They attempt
    a refinement where a low number of rounds and a tournament
    system do not guarantee sufficient distinction between
    players' achievements. However, they must be applied with
    care since they are only marginally better than coin tossing.
    Examples of tie breakers are direct comparison, which
    acknowledges the winner of a game between two players in
    question, and SOS, which is the Sum of Opponents' Scores. -
    The possible degree of quality of tie breakers is subject to
    discussion. It depends on tournament system, whether only the
    top or all players shall be distinguished, and other factors.
    An alternative to the usage of tie breakers for the final
    results ordering is issuing shared places for all players
    with the same number of wins (or McMahon points). - One must
    fairly assign tie breaker points for opponents missing in
    some round; enforcing participation is preferable especially
    for top players.

    6.4 Pairing

    Pairings must be fair, precise, and consider prior
    achievements during a tournament. One should consider colour
    balance and no pair twice, one might also aim at avoiding a
    pair of players from the same club or country, depending on
    a tournament's intentions. Pairings might be done manually
    in small tournaments; for most tournaments pairing programs
    should be used. These can create fair pairings convincingly,
    some even watch global balance.

    6.5 Thinking Times

    The age of killing each other by greater endurance has gone.
    Clocks are used to count each player's remaining thinking
    time. Typically, every game has a basic time and overtime
    periods. Exceeding a time limit loses a game. Basic time
    might be 9 hours for a professional top game, 10 minutes for
    a lightning game, or something in between that fits a
    tournament's intentions. An overtime period requires a fixed
    number of moves within a predetermined period, e.g. 1 move
    within 60 seconds. A move is finished by pressing the clock.
    - Many variants or other time systems exist, e.g., increasing
    numbers of moves in further overtime periods, penalty points
    for entering further periods, full usage of every overtime
    period, thinking time working like an hour glass, etc.

    6.6 Tournament Rules

    Every tournament uses an announced set of tournament rules.
    They especially specify the used set for the core rules of
    play, the tournament system, tie breakers, the pairing
    method, the winning criteria, compensation methods,
    thinking times, direction, jurisdiction, adjournment
    methods, penalities for being late, etc. Tournament rules
    often deal with details. Not everything can be predicted, so
    a sportsmanlike spirit is mentioned. Finally, it should be
    clear which of several rule sets takes precedence.

    6.7 Tournament Organization

    A regional tournament can be organized by a club. Big events
    can be held at the request of an association or federation,
    who also supervise. A tournament organization is responsible
    for providing a venue and playing material. It must be
    distinguished from the tournament director and his assistant
    directors, who perform the particular tasks of pairing,
    collecting results, and ensuring smooth running. Shared
    power furthermore demands independent referees.

    6.8 Jurisdiction

    Before the start of a tournament valid instances of a
    jurisdiction as well as the persons to be referees must be
    clear. Typically, for a tournament itself there is one
    referee as the first instance and a body of three referees
    as the second instance. For very peculiar cases a federation
    could have a third and final instance. Some tournament rules
    replace the second instance by a single person, called chief
    referee; to avoid confusion he ought not to judge as the
    first instance. Players should respect the referees' tough
    job of mediation or decision; referees should seriously
    enforce the rules.

    6.9 Prizes

    The first places of a tournament invoke major prizes. E.g.
    the first, second, third places might get 3/6, 2/6, 1/6 of
    the available money. In a tournament with many weaker
    players it is a good idea to provide some prizes for all
    other players that win most rounds as well. While prizes can
    be money, books, trophies, etc., one should remember that
    money is most universally accepted and trophies serve the
    media better than the winners. -
    On a related topic, a side event lottery must give equal
    chances to all participants. This is only achieved by using
    one lot for each.

    7 Links

    Most rules information, links, short rules: http://home.snafu.de/jasiek/rules.html

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Robert Jasiek@21:1/5 to All on Tue Oct 13 10:26:51 2020
    Title: Rules FAQ
    Author: Robert Jasiek <jasiek@snafu.de>
    Frequency: monthly
    Last Update: 2017-10-13; First Day: 1999-04-12
    Distribution: rec.games.go
    Copyright: free non-commercial usage for promotion

    0 CONTENTS

    1 Purpose of this Paper
    2 Information for Beginners
    3 Important Concepts
    4 Particular Rules
    5 Troublesome Details
    6 Tournament Rules
    7 Links

    1 PURPOSE OF THIS PAPER

    This paper is a basic reference for important rules terms,
    rules, and tournament rules. Beginners should read
    especially Chapters 2 and 3, players Chapters 3 to 5,
    tournament players and organizers Chapter 6.

    2 INFORMATION FOR BEGINNERS
    2.1 What Must I Know as a Beginner?

    The game is played on a grid board. Typically it has 19x19
    intersections, but 9x9 are also fine. Two players compete.
    The first player uses black stones, the other white.

    The players alternate. A player may play or pass. Playing
    is putting one's own stone on an empty intersection and
    removing any surrounded opposing stones. To avoid
    cycles, a play may not recreate any prior configuration of
    all stones on the board.

    Two successive passes end the game. Then the player with
    more intersections wins. Intersections are his if only his
    stones occupy or surround them.

    2.2 Which Rules do I Need as a Beginner?

    You can play with short rules as in 2.1. Other rules may
    be different, but the game is the same, i. e. strategy,
    tactics, and the score do not change. Extremely rare
    exceptions confirm this rule.

    The winner can be determined by area or by territory.
    Either includes empty intersections surrounded only by own
    stones. While area adds intersections occupied by own
    stones, territory adds opposing prisoners instead.

    All rules, except short rules, have further phases after
    alternation and before scoring. Towards a game end it is
    often clear which stones will be removed. The additional
    phases allow the players to agree on which stones shall be
    removed. Thereby final removals do not require alternation.

    Whether you score by area or by territory or whether you
    remove by alternation or by agreement should mainly depend
    on which rules are used by people you play with.

    2.3 Which Rules Should I Teach?

    One possibility is to use a board with 9x9 intersections,
    short rules as in 2.1, and count each player's score by
    using a finger to scan the board for his intersections.

    3 IMPORTANT CONCEPTS

    While strategy and tactics virtually remain the same,
    concepts vary in different rules. However, the following
    gives a comprehensive overview on standard terms.

    3.1 Stone, String

    The physical device that colours one intersection in a
    play is a STONE. Two intersections of the board are
    ADJACENT if they have a line but no intersection between
    them. Two intersections with either black, white, or no
    stones on them are CONNECTED if they are adjacent or if
    there is a chain of adjacent intersections of their type
    between them. A REGION consists of an intersection and
    any intersections connected to it. A black or white
    region is called a STRING.

    3.2 Surrounded

    An intersection of one colour is SURROUNDED by another
    colour if each leaving path reaches the other colour first
    after the one colour. Hereby it can only be surrounded
    black by white, white by black, empty by black, or empty
    by white. A region can be surrounded. For strings there is
    an alternative notion of no liberty (or breath). A LIBERTY
    of a string is an empty intersection adjacent to it. Thus
    a string is surrounded if and only if it has no liberty.

    3.3 Removal, Suicide

    A removal empties the intersections of surrounded stones
    if there are any. Hereby removal of opposing stones is
    executed first, if necessary. Rules may either require or
    forbid removal of own stones. This is called suicide or no
    suicide. In practice, suicide might be used for so called ko
    fights or in capturing races.

    3.4 Capture, Prisoner

    Rules that score territory call a removal a capture
    because all removed stones are seriously kept as prisoners.

    3.5 Move, Play, Pass

    The players have alternate turns. On each turn a player makes
    a move that is either a play or a pass. A play places one's
    own stone on an empty intersection. It can then include
    removal of surrounded stones, if any. A pass merely continues
    alternation by giving the opponent the next turn.

    3.6 Compensation

    The first move advantage by black can be compensated by
    compensation points (komi) that are added to the white score
    after the game end. Komi can be adjusted by 0.5 to avoid
    ties. Today integer values for komi for 19x19 boards
    typically range between 5 and 7. For 13x13 boards one should
    use 8, for 9x9 boards 6; however, there is no real consensus
    for small board komi values yet. -
    A weaker player (black) can get the right to place an agreed
    number of compensation stones (handicap) before white's first
    play. Rules may allow free or fixed handicap. Free handicap
    does not apply any restriction. Fixed handicap requires
    traditional placement on set intersections.

    3.7 Phases

    Normally, a game consists of the phases alternation,
    agreement, scoring. A game stop is between alternation and
    agreement, the game end is between agreement and scoring,
    and after scoring both players accept the counted score as
    the result. The main part of the game is the alternation
    phase. Special rules are invoked after it. Typically, two
    successive passes in alternation are the game stop and start
    the agreement phase. In it the players may agree on strings
    to be removed. If they agree, then they remove those strings
    from the board; this ends the game. Sometimes they might
    disagree, then no strings are removed but alternation is
    resumed as if the last game stop did not occur.

    3.8 Recreation

    The position is the pattern of black and white stones on the
    board. Without extra rule a position might be repeated
    infinitely. The easiest rule to prohibit this says: A play
    may not recreate a position. This refers to positions after
    completion of plays, i.e. after possible removals. The rule
    is called "superko". -
    Some rules use concepts different from superko. They combine
    a "2-play rule" with a "long cycle rule". The first says:
    Two successive plays may not recreate a position. The second
    says: If a position is recreated after more than two moves,
    then the game ends either immediately or, as a variant, as
    soon as the players agree, with the result "without result".
    In practice the 2-play rule is sufficient for almost all
    cases. It handles the relevant standard pattern of two
    adjacent intersections. For superko this is just a special
    application.

    3.9 Scoring

    The score is the result after the game end as defined by
    the rules. There are two different scoring methods: area
    scoring and territory scoring. Rules use one of them. Both
    give the same result in almost all cases and both evaluate
    the difference of the black and the white scores. A player's
    AREA score is the sum of intersections with own stones and
    of empty intersections surrounded only by own stones. Simply
    speaking, a player's TERRITORY score is the sum of empty
    intersections surrounded only by own stones and of prisoners
    of opposing colour. With both scoring methods empty
    intersections that are not surrounded by either black or
    white are neutral.

    3.10 Counting

    A score must be determined by some mechanical procedure in
    practice; this is called counting. There are various methods.
    Some rules prescribe one. A possible method is to use one's
    finger to count point by point. Other methods rearrange a lot
    of stones on the board.

    4 PARTICULAR RULES

    Rules vary extremely. However, in practice they often give
    the same result.

    4.1 Short Rules

    Examples of short rules are the Simple Rules or the
    Tromp-Taylor rules. They have no game stop and no agreement.
    Both are superfluous since necessary removals may already be
    performed in the alternation. Two successive passes end the
    game that is scored then. Short rules use area scoring,
    superko, and suicide. Further settings are left for
    tournament rules.

    4.2 American Rules

    These are used by the American Go Association. They use
    situational superko, no suicide, and 7.5 komi. They permit
    free or fixed handicap. Their most remarkable feature is to
    allow one of area scoring or territory scoring. Herefore
    pass stones (one prisoner compensates each pass) and white
    moving last always ensure the same result, regardless of the
    applied scoring method.

    4.3 Chinese Rules

    These are used in continental China and sometimes in other
    countries. Area scoring and no suicide are used.

    4.3.1 Official Chinese Rules

    In practice, ko rules roughly amount to a 2-play rule and a
    long cycle rule. The mentioned superko is overridden. The
    counting is a sophisticated half counting, where empty
    intersections and then after rearrangements stones of one
    colour are added to be compared with half the non-neutral
    intersections. The komi as a half komi is 3.75. In full
    counting, counts and komi would be twice as big.

    4.3.2 Simplified Chinese Rules

    Positional superko is used. A counting method is not
    prescribed. The full komi should be 7.5.

    4.4 Japanese Rules

    The differences mainly affect handling of late game phases
    but often do not alter scores. Japanese rules use some
    traditional territory scoring that attempts to exclude so
    called sekis. No suicide applies. The core of the ko rules
    is a 2-play rule and a long cycle rule. Typically, komi is
    6.5. Fixed handicap should be used. The counting is a
    sophisticated rearrangement of empty intersections and
    filling-in of prisoners.

    4.4.1 Game Finishing Process

    A game finishes with the following process: 1) So called
    dame (neutral points) and defensive moves (necessary
    connections etc. due to occupied dame) are filled.
    2) The hypothetical analysis, which presumes perfect play,
    determines so called life or death of each string and the
    scoring intersections. 3) Without making any approach moves,
    dead stones are removed from scoring intersections and added
    to the prisoners. 4) The score is counted. (2) and (3) do not
    allow to play out life and death since actually filling
    intersections costs points in Japanese rules.

    4.4.2 Official Japanese Rules

    There are the Japanese 1989 Rules, which are used in Japan
    and elsewhere, and the World Amateur Go Championships Rules,
    which are used in some particular tournaments. Korean rules
    are similar to Japanese rules but have a very different text
    and differ in rare positions. Official Japanese rules are
    very incomplete and have messy late game phases. E.g., the
    Japanese 1989 Rules allow filling of dame during alternation,
    after it, or both and have a so called ko-pass-rule for the
    hypothetical analysis. Now professional Japanese rules are
    explained precisely by a rules expert's interpretation called
    "the Japanese 2003 Rules".

    4.4.3 Simplified Japanese Rules

    As a recent invention, they are not used yet. They are
    complete and have clear late game phases. Filling of dame is
    done during alternation.

    4.4.4 Verbal Japanese Rules

    They are used for informal games in many countries and
    undefined, except that the game finishing process is used.
    In a tournament without any official rules of play, disputes
    are not solved due to the rules but with a referee.

    4.5 Ing Rules

    Ing rules use area scoring, suicide, 8 komi with black
    winning ties, and free handicap.

    4.5.1 Official Ing Rules

    The ko rules are a mess but somehow resemble superko.
    Details could fill books. The late game phases are specified
    insufficiently. The peculiar counting method requires 180
    stones of each colour throughout the game, fills any stones
    on the board after the game end, and leaves exactly one
    empty intersection, which determines the winner. The
    official rules are used in professional Taiwanese and some
    sponsored tournaments. Taiwanese amateurs have their own
    rules.

    4.5.2 Simplified Ing Rules

    Positional superko is used. A counting method is not
    prescribed. The late game phases are specified clearly. The
    simplified rules are used in EGF tournaments that are said
    to use Ing rules.

    4.6 New Zealand Rules

    Area scoring, suicide, situational superko, 7 komi, and free
    handicap are used.

    4.7 Go Server Rules

    Every go server has its own and often complicated rules, if
    any, so they cannot be given in detail here. Concerning
    "IGS rules", territory scoring, no suicide, a 2-play rule,
    fixed handicap, three game stopping passes, and captures in
    an agreement phase are used. Details about agreements and
    long cycles are not specified and lead to adjourned games in
    case of doubt. Komi is suggested but may be altered. Counting
    is automatic. "Yahoo" has territory scoring, no suicide, a
    2-play rule, two game stopping passes; long cycles and
    disagreements are not handled properly. On "email servers"
    players must agree on any rules. -
    Typically territory scoring on a go server means that neither
    points in any sekis are excluded nor pass stones are used.
    Thus while the Japanese seki exception is abandoned,
    disagreements about removals may lead to games without result
    since playing out can cost points.

    4.8 International Rules

    The international mailing list go-rules has proposed
    international rules, however, none are adopted yet. The core
    rules of play shall be clear, complete, and correct.
    Currently alternative texts are offered for suicide,
    recreation, and scoring. Especially unification of scoring
    methods is advocated.

    4.9 EGF Rules

    The EGF uses the Simplified Ing Rules with 8 komi (black
    wins ties) in Ing sponsored tournaments and the Nihon Kiin
    1989 Rules with 6.5 komi in Japanese/Korean sponsored
    tournaments. If significantly the European Go Championship
    has both kinds of sponsors, then boards 1-16 use the Nihon
    Kiin 1989 Rules and boards 17+ the Simplified Ing Rules.
    However, time settings depend on ranks.

    5 TROUBLESOME DETAILS

    5.1 Colour Choice

    In even games typically the colours are randomly chosen. In
    handicap games black receives the handicap stones. -
    A manual method for randomly choosing colours is called
    nigiri. The older player hides a number of white stones
    taken from the bowl, the opponent takes one or two black
    stones to guess the parity, and the parity of the number of
    white stones is revealed. If the opponent guesses right,
    then he takes black, else he takes white.

    5.2 Pass Stones

    Some rules use pass stones. A passing player adds one own
    stone to the prisoners. As a consequence, captures before
    the game end can be resolved in alternation without any loss
    because any not answered approach move is compensated by one
    pass stone. With traditional territory scoring that uses no
    pass stones definition problems arise due to this missing
    option. Modern territory scoring or equivalence scoring use
    pass stones.

    5.3 Equivalence

    Area scoring and territory scoring are close because either
    intersections occupied by own stones or opposing prisoners
    are used. Essentially, every prisoner is a stone removed
    from some intersection. For area it scores one point less
    for the stone's player while for territory it scores one
    point more for his opponent. This is equal. Exact equality
    for the entire game must also consider passes by using pass
    stones and an equal number of moves by requiring white to
    pass last. This is done by equivalence scoring.

    5.4 Meaning of Agreement Removals

    Removals in an agreement phase under area scoring are fair
    because they may as well occur in alternation. Removing a
    stone due to agreement includes its then empty intersection
    and all adjacent empty intersections in the score. Removing
    a stone by means of alternation includes its then empty
    intersection and all adjacent newly occupied intersections
    in the score. -
    With traditional territory scoring this is not possible
    since stones on the board do not score. Thus final captures
    must occur after the game end due to attempted definitions
    in the rules.

    5.5 Practical Scoring Differences

    Since area scoring and modern territory scoring using pass
    stones are equal, correct play is the same for both. Apart
    from Japanese rules exceptions like not scoring empty
    intersections especially in asymmetrical coexistences or
    like a pass-for-ko-rule, traditional territory scoring can
    make a different winner in practically ca. every 10000th
    even game. This is so rare because of a parity feature
    combined with a scarcely odd number of intersections that
    are in coexistences but do not score for area at the game
    end. With area scoring a komi change from 1.5, 3.5, 5.5, ...
    to 2.5, 4.5, 6.5, ... almost always would not change the
    winner. So altough occupying the last empty intersections
    that would otherwise not score just before a game stop gains
    one point each, alternately doing so leaves a total
    advantage of at most one point. Due to the parity feature
    the player to get it is predetermined when this occupation
    starts. More importantly, one final ko is worth 1 point under
    traditional territory scoring but 2 or rarely 4 points under
    area scoring. Rare one-sided points in coexistences provide
    only area. Other practical differences are even rarer. Cute
    players include the stones in their endgame value counts
    during the middle of an area scoring game.

    5.6 Stone Scoring

    In ancient times stone scoring was popular. Only stones on
    the board are scored. Thus empty intersections surrounded by
    own stones are filled until necessary so called eyes remain.
    Disconnected stones require more eyes in total, the so
    called group tax.

    5.7 Old Ing Scoring

    Old Ing rules allowed fractional scores by assigning points
    to neutral empty regions due to the percentage of black and
    white stones surrounding every region.

    5.8 Primitive Rules

    They do not have passes. Alternation ends when a player
    loses due to no legal play. Games can be extremely long and
    include special strategies, so called pass fights. Primitive
    rules (also called no pass rules or Conway rules) can be
    useful in mathematics.

    5.9 Tradition

    Historically, exceptions arose, which some like as such
    especially together with Japanese style rules. So called
    sekis are excluded from the score. Special positions, termed
    precedents, have special rules. Modern Japanese rules have
    generalized a lot of them by a pass-for-ko-rule. After the
    game stop or after the game end and particularly in
    hypothetical play a stone captured in a possible 2-play cycle
    may not be recaptured unless before a pass is made that
    specifies the particular 2-play cycle.

    5.10 Positional / Situational Superko

    Positional superko prohibits a play that recreates a position.
    Situational superko refers to the situation, i.e. to the
    position together with the right to move. So a play is
    prohibited if it recreates a position while the same player
    has the right to move. In practice the differences are
    extremely rare.

    5.11 Handicap Recompensation

    With area scoring handicap stones beyond the first provide
    a potential extra area of one point per handicap stone. Komi
    for white may consider this. Recompensation, H-1 points for H
    handicap stones, is virtually only used together with
    American rules.

    5.12 Mathematics

    Go is a complete information game, i.e. at every move each
    player knows the entire game situation. Hence theoretically
    an algorithm could determine perfect play. However, due to
    the complexity of the game with N intersections, for which
    it is provably impossible to devise a polynomial time
    solution, perfect play or ideal komi are unknown. What one
    does know is that in a game without komi the first player wins
    or ties and that perfect play is independent of set komi. Many
    other propositions have been discovered, some of which
    describe the relation between area and territory scoring, solve
    tiny endgame positions or cyclical behaviour. -
    Go is a very complex game! According to John Tromp, the number
    of legal positions is:

    208168199381979984699478633344862770286522453884530548425 639456820927419612738015378525648451698519643907259916015 628128546089888314427129715319317557736620397247064840935

    For positional superko, no passes, and no resignation, the
    number of possible games is smaller than N**L(N) because L(N)
    also restricts the maximal number of moves per game and there
    are at most N possible intersections per move. (The sign ** is
    a text file notation for "to the power".) -
    Extremely modest estimates look like 10**N, which is based on
    an assumption of 10 reasonable intersections per move. A
    popular estimate for 19x19 go is 10**761, which must have
    originated from a typo and should be 10**361, if at all...
    These types of estimates are so popular because humans cannot
    even imagine the suggested number of atoms in the universe,
    10**80. For comparison, 3**361 is ca. 10**172.

    6 TOURNAMENT RULES

    6.1 Special Game Ends

    If the score considering the komi is zero, then the game is a
    tie and should be treated as 0.5 won games for each. Special
    rules or undue behaviour like sincere lateness might result
    in a referee declaring a win by forfeit, 0:0, or 1:1,
    whichever is most appropriate.

    6.2 Tournament Systems

    A tournament might consist of several stages, of which each
    has a seed and a system. A seed appropriately restricts
    participation, e.g. due to qualification. The most important
    systems are match, league, knockout, Swiss, McMahon. There
    are many others and hybrids. A system must fit the aims of a
    tournament. A sufficient number of rounds, a proper seed,
    and colour variation ensure a fair determination of the best
    player. -
    A match takes place between two players that either play a
    set number of games to see who wins more or a maximal number
    of games to see who wins a predetermined number of games
    first. In a league a small, usually even number of players
    performs a round-robin tournament, so that in each round all
    players play and every two players play against each other,
    one game e.g. A knockout preferably starts with a number of
    players that is a power of two. Losing players are eliminated,
    winning players continue until the winner remains. -
    In a Swiss system before each round each player's achieved
    number of wins is used to pair players with equal numbers as
    far as possible. So all players play all rounds and some time
    the best player will emerge. However, with greatly varying
    strengths too many rounds would be needed. So Swiss is only
    useful for particular events or handicap tournaments.
    McMahon is the refinement of Swiss. Before the start of the
    tournament all players are classified in rank groups, with
    ranks R from 0 to T. This means that one assumes a preceding
    Swiss tournament where every player has already won R games.
    Then in the McMahon tournament the strongest players, who
    deserve the rank T, compete for the top places. In practice,
    one uses a bar B, that is 1 or 2 ranks below T, so that all
    ranks above B are contracted to B and also players slightly
    weaker than the top players get their chance. All players in
    a McMahon play roughly equal opponents; if they win or lose,
    then the opponents will be stronger or weaker.

    6.3 Tie Breakers

    Tie breakers can refine pairings or results. Typically the
    first criterion is the number of wins (or McMahon points);
    all further criteria, if any, are tie breakers. They attempt
    a refinement where a low number of rounds and a tournament
    system do not guarantee sufficient distinction between
    players' achievements. However, they must be applied with
    care since they are only marginally better than coin tossing.
    Examples of tie breakers are direct comparison, which
    acknowledges the winner of a game between two players in
    question, and SOS, which is the Sum of Opponents' Scores. -
    The possible degree of quality of tie breakers is subject to
    discussion. It depends on tournament system, whether only the
    top or all players shall be distinguished, and other factors.
    An alternative to the usage of tie breakers for the final
    results ordering is issuing shared places for all players
    with the same number of wins (or McMahon points). - One must
    fairly assign tie breaker points for opponents missing in
    some round; enforcing participation is preferable especially
    for top players.

    6.4 Pairing

    Pairings must be fair, precise, and consider prior
    achievements during a tournament. One should consider colour
    balance and no pair twice, one might also aim at avoiding a
    pair of players from the same club or country, depending on
    a tournament's intentions. Pairings might be done manually
    in small tournaments; for most tournaments pairing programs
    should be used. These can create fair pairings convincingly,
    some even watch global balance.

    6.5 Thinking Times

    The age of killing each other by greater endurance has gone.
    Clocks are used to count each player's remaining thinking
    time. Typically, every game has a basic time and overtime
    periods. Exceeding a time limit loses a game. Basic time
    might be 9 hours for a professional top game, 10 minutes for
    a lightning game, or something in between that fits a
    tournament's intentions. An overtime period requires a fixed
    number of moves within a predetermined period, e.g. 1 move
    within 60 seconds. A move is finished by pressing the clock.
    - Many variants or other time systems exist, e.g., increasing
    numbers of moves in further overtime periods, penalty points
    for entering further periods, full usage of every overtime
    period, thinking time working like an hour glass, etc.

    6.6 Tournament Rules

    Every tournament uses an announced set of tournament rules.
    They especially specify the used set for the core rules of
    play, the tournament system, tie breakers, the pairing
    method, the winning criteria, compensation methods,
    thinking times, direction, jurisdiction, adjournment
    methods, penalities for being late, etc. Tournament rules
    often deal with details. Not everything can be predicted, so
    a sportsmanlike spirit is mentioned. Finally, it should be
    clear which of several rule sets takes precedence.

    6.7 Tournament Organization

    A regional tournament can be organized by a club. Big events
    can be held at the request of an association or federation,
    who also supervise. A tournament organization is responsible
    for providing a venue and playing material. It must be
    distinguished from the tournament director and his assistant
    directors, who perform the particular tasks of pairing,
    collecting results, and ensuring smooth running. Shared
    power furthermore demands independent referees.

    6.8 Jurisdiction

    Before the start of a tournament valid instances of a
    jurisdiction as well as the persons to be referees must be
    clear. Typically, for a tournament itself there is one
    referee as the first instance and a body of three referees
    as the second instance. For very peculiar cases a federation
    could have a third and final instance. Some tournament rules
    replace the second instance by a single person, called chief
    referee; to avoid confusion he ought not to judge as the
    first instance. Players should respect the referees' tough
    job of mediation or decision; referees should seriously
    enforce the rules.

    6.9 Prizes

    The first places of a tournament invoke major prizes. E.g.
    the first, second, third places might get 3/6, 2/6, 1/6 of
    the available money. In a tournament with many weaker
    players it is a good idea to provide some prizes for all
    other players that win most rounds as well. While prizes can
    be money, books, trophies, etc., one should remember that
    money is most universally accepted and trophies serve the
    media better than the winners. -
    On a related topic, a side event lottery must give equal
    chances to all participants. This is only achieved by using
    one lot for each.

    7 Links

    Most rules information, links, short rules: http://home.snafu.de/jasiek/rules.html

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