• Review: The Endgame (Ogawa / Davies)

    From Robert Jasiek@21:1/5 to All on Mon Aug 27 18:05:55 2018
    Review: The Endgame (Ogawa / Davies)

    General Specification

    * Title: The Endgame
    * Author: Tomoko Ogawa, James Davies
    * Publisher: Ishi Press (now: Kiseido)
    * Edition: 1982 (2nd printing, brown cover)
    * Language: English
    * Price: EUR 16.50
    * Contents: endgame
    * ISBN: none (now: [?])
    * Printing: good
    * Layout: almost good
    * Editing: good
    * Pages: 211
    * Size: 127mm x 181mm
    * Diagrams per Page on Average: 3
    * Method of Teaching: principles, examples
    * Read when EGF: 10k - 3k
    * Subjective Rank Improvement: -
    * Subjective Topic Coverage: --
    * Subjective Aims' Achievement: +

    Preface

    Although this is an old book first published in English in 1976, it is
    still sold because it is well-known and part of the Elementary Go
    Series. There are still only a few English endgame books so the book
    remains an option to be considered. My impression when I read the book
    as circa a 5 kyu is almost the same as when I reread it in 2018, 28
    years later, as a 5 dan and endgame researcher, except that then it
    was the only English endgame book and now I can better justify my
    impression.

    Overview

    The book has five chapters. Chapter 1 uses one game to introduce the
    endgame informally. The game comments are mostly uninteresting
    descriptions ("White 38 threatened an invasion of the upper right
    corner again, so I defended at 39.") but interludes prepare the reader
    softly for the next chapter, show variations of enclosure josekis,
    which a reader of expected rank may find useful, or give a sample
    illustration of counting territory during the game. For that purpose,
    the diagram annotation is a bit strange: for the sake of counting in
    pairs, two adjacent intersections carry the same integer.

    Chapter 2 is the core of the book. It explains evaluation of moves of
    local endgames. First, some theory is explained shortly. Second, nine
    problem diagrams each with three local endgames, a few answer diagrams
    and one combination diagram per problem train application of the
    theory. Apparently, the combination diagrams presume an unshown whole
    board context during the early to intermediate endgame, where the
    three local endgames must be played first in their correct move order.

    Chapter 3 shows a good variety of the most basic endgame tesujis and a
    few problems for each type. If you have not seen the monkey jump or
    other tesujis of a comparable, basic level before, the chapter should
    be useful.

    The macroendgame (transition from the late middle game to the early
    endgame) is the topic of chapter 4. There are nine whole board
    problems each with five moves to choose from. The answers are short.
    That is all. Chapter 5 is similar but shows two games during the
    intermediate endgame, each with ten problems and multiple choice among
    three candidate moves.

    Except for the interludes in chapter 1, the chapters 1, 4 and 5 are
    mostly filling material trying to compensate the too short theory in
    chapter 2. In particular the macroendgame would have deserved general
    theory and at least careful approximative calculations of the move
    values of the top two candidates. Instead, we mostly get disappointing
    informal text, such as "Although tbe continuation is a bit difficult,
    there is no question that Black 1 is the right move".

    The Theory

    Chapter teaches move values of gote, sente, reverse sente and double
    sente for traditional endgame theory, where you multiply by two for
    playing in sente or reverse sente to compare with playing in gote. The
    book compares "Black goes first" and "White goes first" but avoids a
    term for the calculated difference value. It compares the two
    resulting local positions but avoids terms for them (nowadays we call
    them black and white follower) and the counted value (we would call
    them the count). It counts locally but does not explain the concept of
    locality (which I would call the locale). It studies follow-ups but
    avoids this term like the plague. To calculate the impact of a
    follow-up on a move value, it sometimes considers the white follower's
    white follower or the black follower's black follower but, as we know,
    avoids these terms. Instead, it uses various, confusing, informal
    descriptions for the same term, concept or value. The reader must
    enlighten himself. Likewise, the book describes newly acquired values
    by different phrases with a preference for "to gain". As a
    consequence, the author herself lacks a clear understanding and
    sometimes makes the mistake of adding gote and sente gains without
    first calibrating such different values.

    Furthermore, the book tries to simplify. It approximates by rounding
    to avoid fractions and prune the impact of iterative follow-ups on
    move values. Although this works for the simple examples in the book,
    this also means that the reader does not learn determination of move
    values of local endgames with intermediate to large iterative
    follow-up positions. The book speaks of average, mathematical average
    or mean (all meaning the same) but does not explain how to calculate
    an average. For the simplest calculation, the calculation shown
    multiplies a value by 1/2, puts this in brackets and adds this to some previously calculated value. Otherwise, the book avoids brackets for arithmetic. It invents, however, a creative alternative use for
    brackets to indicate a rounded value as being slightly smaller, such
    as "5(-)", or larger, such as "5(+)", than an integer. It also avoids
    negative numbers but speaks of White's points. This may work for the
    simple examples of the book, but the reader does not learn proper
    calculation in general. Funnily, the book cannot quite admit to avoid
    negative numbers when writing "the total difference is 1+1=2 points".
    If White's points were accounted properly as negative points, we would
    indeed have the difference "1 - (-1) = 2". After dissolution of
    bracket and minus signs, this becomes the sum stated in the book.

    Does the reader profit from all those attempts of simplification?
    Hardly. Besides the few principles hidden in ordinary text, he has to
    make sense of several different methods of how a gote follow-up is
    calculated. Sometimes it is the average of two numbers, the average of
    one number (and - not declared by the book - the number zero), derived
    from the white follower's white follower and an average, or derived
    from the black follower's black follower and an average. Without the
    underlying theoretical explanations why each method works and produces
    correct move values, it can be hard to understand everything while
    overcoming confusion.

    At least, the move values in the book are correct if we tolerate approximations. Sometimes the author was lazy and an approximation is
    correct only plus-minus 2 points. The explanation of theory for sente,
    reverse sente and double sente is even shorter. The relative value of
    sente or reverse sente are explained by an argument fitting modern
    endgame theory: points per difference in the numbers of played stones. Unfortunately, this is the only aspect of modern theory in the book.

    More confusion arises when gote and gote (or sente and sente) have
    different meanings. Either word might refer to the type of local
    endgame or to the kind of sequence but the book never says "gote
    sequence" or "sente sequence" when it means such. The reader must
    always disambiguate the context, especially when both contexts occur
    in the same sentence. Worst of all, we learn that a reverse sente "is
    gote". What this means is that a move played in reverse sente starts a
    gote sequence. Such problems occur when a book does not properly
    introduce the basics and avoids by far too many terms, which would
    clarify everything.

    Not surprisingly, the book introduces double sente as "either side can
    play in sente", means local double sente and is unaware of its
    inexistence. As a consequence, the answers to the problems calculate
    move values in double sente even when the most obviously the follow-up
    threats are too small by far. In the most obvious example, the author
    noticed this by herself ("Black 1 is not necessarily sente, either.")
    but did not draw the right conclusion. The harm from this conceptual
    mistake is limited though because the book offers useful practical
    advice for when to play double sente.

    From the theory and problems in chapter 2, the reader learns
    calculation of move values of gote or sente without follow-up. Hardly
    from the theory alone - but from the combination of theory and
    problems. Learning reverse sente is made more difficult. Maybe the
    bright reader also learns calculation of a move value if the local
    endgame has simple, direct follow-ups. However, calculation of a move
    value is peculiar in the book: only intersections of either player's territories with changes are counted by mentally comparing two
    diagrams. This works for the simple examples in the book but the
    method might fail for more difficult examples.

    The Missing Theory

    Endgame evaluation in the book misses the following theory: in general
    exact move values instead of approximations, move values of local
    endgames with iterative follow-ups and larger impact than rounding approximations, a careful explanation of the basics, basic terms,
    basic concepts other than move value, count of an initial local
    endgame, counts of followers, evaluation of ordinary kos or ko
    threats, gains (when Black's and White's moves gain different amounts
    not both described by the move value), net profit, theory relating the different values, careful study of different kinds of follow-ups,
    modern endgame theory, microendgame, area scoring, a clear
    distintinction of sente and gote, ambiguous local endgames, evaluation
    of long local sequences, value theory for move order during the early
    and late endgames, advanced theories.

    Conclusion

    The book is written for beginners of endgame theory. Apart from the
    additional chapters, it only touches the only one aspect of move
    value. The unclear, confusing presentation with countless omissions
    especially of basic descriptions make good understanding of the
    contents unnecessarily hard especially for the intended readership.
    Theory and didactics of the book are outdated.

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  • From Robert Jasiek@21:1/5 to All on Tue Aug 28 08:27:37 2018
    Elsewhere, there has been the good suggestion to add a disclaimer, so
    here it is:


    Disclaimer: Robert Jasiek is a researcher in the endgame and other go
    theory, author of endgame books and other go books, and go teacher.

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