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  • 36 to play from the bar

    From ah....Clem@21:1/5 to All on Tue Aug 23 10:51:43 2022
    XGID=--aa--D-C--AdD---d-c-b--BA:0:0:1:36:0:0:3:0:10

    X:Player 1 O:Player 2
    Score is X:0 O:0. Unlimited Game, Jacoby Beaver
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X O | | O O X |
    | X O | | O O X |
    | X O | | O |
    | X O | | |
    | | X | |
    | |BAR| |
    | | | |
    | O | | X |
    | O X | | X |
    | O X | | X |
    | O X X | | X O O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 184 O: 155 X-O: 0-0
    Cube: 1
    X to play 36

    --
    Ah....Clem
    The future is fun, the future is fair.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Timothy Chow@21:1/5 to ah....Clem on Tue Aug 23 21:57:34 2022
    On 8/23/2022 10:51 AM, ah....Clem wrote:


    XGID=--aa--D-C--AdD---d-c-b--BA:0:0:1:36:0:0:3:0:10

    X:Player 1   O:Player 2
    Score is X:0 O:0. Unlimited Game, Jacoby Beaver
     +13-14-15-16-17-18------19-20-21-22-23-24-+
     | X           O    |   | O     O        X |
     | X           O    |   | O     O        X |
     | X           O    |   | O                |
     | X           O    |   |                  |
     |                  | X |                  |
     |                  |BAR|                  |
     |                  |   |                  |
     | O                |   | X                |
     | O           X    |   | X                |
     | O           X    |   | X                |
     | O  X        X    |   | X        O  O    |
     +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count  X: 184  O: 155 X-O: 0-0
    Cube: 1
    X to play 36


    My first instinct is to play bar/16, but we're far behind in the
    pip count, so running is probably the wrong idea. Although it
    looks a bit loose to slot with 11/5, it's at least the right
    strategic idea: with more checkers back and an anchor, we can
    afford some boldness, and we'd like to form a prime. It's a
    double shot but 3's are duplicated. I'll try 11/5.

    ---
    Tim Chow

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  • From badgolferman@21:1/5 to ah....Clem on Wed Aug 24 13:10:24 2022
    ah....Clem wrote:



    XGID=--aa--D-C--AdD---d-c-b--BA:0:0:1:36:0:0:3:0:10

    X:Player 1 O:Player 2
    Score is X:0 O:0. Unlimited Game, Jacoby Beaver
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X O | | O O X |
    | X O | | O O X |
    | X O | | O |
    | X O | | |
    | | X | |
    | |BAR| |
    | | | |
    | O | | X |
    | O X | | X |
    | O X | | X |
    | O X X | | X O O | +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 184 O: 155 X-O: 0-0
    Cube: 1
    X to play 36


    My play would be Bar/22, 24/18. Let's force O to protect the 18-point
    and with two separated checkers in his home I may be able to hit back.

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  • From Stick Rice@21:1/5 to Tim Chow on Thu Aug 25 00:45:51 2022
    On Tuesday, August 23, 2022 at 9:57:39 PM UTC-4, Tim Chow wrote:
    On 8/23/2022 10:51 AM, ah....Clem wrote:


    XGID=--aa--D-C--AdD---d-c-b--BA:0:0:1:36:0:0:3:0:10

    X:Player 1 O:Player 2
    Score is X:0 O:0. Unlimited Game, Jacoby Beaver
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X O | | O O X |
    | X O | | O O X |
    | X O | | O |
    | X O | | |
    | | X | |
    | |BAR| |
    | | | |
    | O | | X |
    | O X | | X |
    | O X | | X |
    | O X X | | X O O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 184 O: 155 X-O: 0-0
    Cube: 1
    X to play 36

    My first instinct is to play bar/16, but we're far behind in the
    pip count, so running is probably the wrong idea. Although it
    looks a bit loose to slot with 11/5, it's at least the right
    strategic idea: with more checkers back and an anchor, we can
    afford some boldness, and we'd like to form a prime. It's a
    double shot but 3's are duplicated. I'll try 11/5.

    ---
    Tim Chow

    I would play bar/16 but would not call it a 'running play'.

    Stick

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  • From pepstein5@gmail.com@21:1/5 to badgolferman on Thu Aug 25 01:59:32 2022
    On Wednesday, August 24, 2022 at 2:10:26 PM UTC+1, badgolferman wrote:
    ah....Clem wrote:



    XGID=--aa--D-C--AdD---d-c-b--BA:0:0:1:36:0:0:3:0:10

    X:Player 1 O:Player 2
    Score is X:0 O:0. Unlimited Game, Jacoby Beaver
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X O | | O O X |
    | X O | | O O X |
    | X O | | O |
    | X O | | |
    | | X | |
    | |BAR| |
    | | | |
    | O | | X |
    | O X | | X |
    | O X | | X |
    | O X X | | X O O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 184 O: 155 X-O: 0-0
    Cube: 1
    X to play 36
    My play would be Bar/22, 24/18. Let's force O to protect the 18-point
    and with two separated checkers in his home I may be able to hit back.
    I would do that too, but I Walted your post before making my own decision.

    Paul

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  • From pepstein5@gmail.com@21:1/5 to Stick Rice on Thu Aug 25 01:58:26 2022
    On Thursday, August 25, 2022 at 8:45:53 AM UTC+1, Stick Rice wrote:
    On Tuesday, August 23, 2022 at 9:57:39 PM UTC-4, Tim Chow wrote:
    On 8/23/2022 10:51 AM, ah....Clem wrote:


    XGID=--aa--D-C--AdD---d-c-b--BA:0:0:1:36:0:0:3:0:10

    X:Player 1 O:Player 2
    Score is X:0 O:0. Unlimited Game, Jacoby Beaver +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X O | | O O X |
    | X O | | O O X |
    | X O | | O |
    | X O | | |
    | | X | |
    | |BAR| |
    | | | |
    | O | | X |
    | O X | | X |
    | O X | | X |
    | O X X | | X O O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 184 O: 155 X-O: 0-0
    Cube: 1
    X to play 36

    My first instinct is to play bar/16, but we're far behind in the
    pip count, so running is probably the wrong idea. Although it
    looks a bit loose to slot with 11/5, it's at least the right
    strategic idea: with more checkers back and an anchor, we can
    afford some boldness, and we'd like to form a prime. It's a
    double shot but 3's are duplicated. I'll try 11/5.

    ---
    Tim Chow
    I would play bar/16 but would not call it a 'running play'.

    That's correct. It's actually a walking play. When you run, you
    aim to get somewhere fast. Since we leave two in the inner board,
    we are emerging slowly not fast and so this is a walking play.
    It can also be called a dawdling play or a somnambulant play.

    I've been having all sorts of spills and thrills, slotting to the opponent's bar point
    when I don't know what else to do and when it isn't obviously wrong.
    [Of course, this really asks for a Stickism. "No, it is absolutely obviously wrong.
    It should be obvious to anyone..."]

    24/18 for me.

    Paul

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  • From pepstein5@gmail.com@21:1/5 to Stick Rice on Thu Aug 25 02:16:00 2022
    On Thursday, August 25, 2022 at 8:45:53 AM UTC+1, Stick Rice wrote:
    On Tuesday, August 23, 2022 at 9:57:39 PM UTC-4, Tim Chow wrote:
    On 8/23/2022 10:51 AM, ah....Clem wrote:


    XGID=--aa--D-C--AdD---d-c-b--BA:0:0:1:36:0:0:3:0:10

    X:Player 1 O:Player 2
    Score is X:0 O:0. Unlimited Game, Jacoby Beaver +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X O | | O O X |
    | X O | | O O X |
    | X O | | O |
    | X O | | |
    | | X | |
    | |BAR| |
    | | | |
    | O | | X |
    | O X | | X |
    | O X | | X |
    | O X X | | X O O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 184 O: 155 X-O: 0-0
    Cube: 1
    X to play 36

    My first instinct is to play bar/16, but we're far behind in the
    pip count, so running is probably the wrong idea. Although it
    looks a bit loose to slot with 11/5, it's at least the right
    strategic idea: with more checkers back and an anchor, we can
    afford some boldness, and we'd like to form a prime. It's a
    double shot but 3's are duplicated. I'll try 11/5.

    ---
    Tim Chow
    I would play bar/16 but would not call it a 'running play'.

    Stick
    I just googled it a bit.
    Stick's point on the terminology seems correct.
    "Running play" surely means "checker play preparing for a running game", although I
    haven't seen that stated explicitly.
    In a position where we're so far from being able to run successfully, we don't have a "running play".
    The standard opening 65 is a running play because it only leaves a single checker back that we need
    to run.

    Paul

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  • From Timothy Chow@21:1/5 to Stick Rice on Thu Aug 25 07:48:02 2022
    On 8/25/2022 3:45 AM, Stick Rice wrote:

    I would play bar/16 but would not call it a 'running play'.

    What would the Nactation 63R mean in this position? This is
    a genuine question because I don't remember the exact definitions.
    I think bar/22 24/18 would be 63U.

    ---
    Tim Chow

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  • From pepstein5@gmail.com@21:1/5 to Tim Chow on Thu Aug 25 05:54:02 2022
    On Thursday, August 25, 2022 at 12:48:07 PM UTC+1, Tim Chow wrote:
    On 8/25/2022 3:45 AM, Stick Rice wrote:

    I would play bar/16 but would not call it a 'running play'.
    What would the Nactation 63R mean in this position? This is
    a genuine question because I don't remember the exact definitions.
    I think bar/22 24/18 would be 63U.

    ---
    Tim Chow

    63R would mean bar/16, from my understanding.
    As I see it, Nactation relies on the "Nactators" having significant backgammon experience.
    It's not a totally objective notation system suitable for universal use like a chess notation system would be.

    I think the idea is that you imagine talking about the move and ask yourself what word you would use,
    Would the word be "run", "split", "slot" etc?
    Here you might say I run with bar/16.

    But you said (something like) "It's a running play and ... [positional commentary]"
    In that context, I would expect "running play" to be defined as "move preparing to run my checkers home."
    In which case, I don't think your play is a running play.
    In the context of looking for a Nactation, your play would be a running play. Different contexts, different interpretations.

    Suppose a player has a significant other, and is playing backgammon in the evening, and suddenly remembers that
    they had promised to be home by 7pm. In that case, they might suddenly run home, after hastily negotiating their debts
    or payments.
    In this case, because they "run home", the previous checker play was necessarily a running play, even if it was 8/5 6/5.

    Paul

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  • From Timothy Chow@21:1/5 to peps...@gmail.com on Thu Aug 25 09:47:25 2022
    On 8/25/2022 8:54 AM, peps...@gmail.com wrote:
    But you said (something like) "It's a running play and ... [positional commentary]"

    I did not use the term "running play." Nor did Stick actually
    say that I used the term "running play."

    ---
    Tim Chow

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  • From ah....Clem@21:1/5 to All on Fri Aug 26 16:07:44 2022
    My take was that all four options seemed playable, so I invoked Pottle's
    law to settle on bar/16. That's favored by the rollout, but only at
    the 91% confidence level after 5484 games.

    I can't say I understand why Pottle's law works as often as it does.

    In the variant, I've improved O's position by making the defensive five
    point; XG then favor's Tim's idea of hanging back and slotting a forward
    point.


    XGID=--aa--D-C--AdD---d-c-b--BA:0:0:1:63:0:0:3:0:10

    X:Player 1 O:Player 2
    Score is X:0 O:0. Unlimited Game, Jacoby Beaver
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X O | | O O X |
    | X O | | O O X |
    | X O | | O |
    | X O | | |
    | | X | |
    | |BAR| |
    | | | |
    | O | | X |
    | O X | | X |
    | O X | | X |
    | O X X | | X O O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 184 O: 155 X-O: 0-0
    Cube: 1
    X to play 63

    1. Rollout¹ Bar/16 eq:-0.580
    Player: 38.11% (G:8.03% B:0.35%)
    Opponent: 61.89% (G:23.06% B:2.04%)
    Confidence: ±0.009 (-0.589..-0.571) - [91.0%]
    Duration: 5 hours 17 minutes

    2. Rollout¹ Bar/22 24/18 eq:-0.590 (-0.010)
    Player: 37.80% (G:8.32% B:0.37%)
    Opponent: 62.20% (G:26.79% B:2.39%)
    Confidence: ±0.012 (-0.602..-0.578) - [9.0%]
    Duration: 2 hours 42 minutes

    3. Rollout¹ Bar/22 11/5 eq:-0.604 (-0.024)
    Player: 38.12% (G:8.23% B:0.36%)
    Opponent: 61.88% (G:24.19% B:2.33%)
    Confidence: ±0.009 (-0.613..-0.594) - [0.0%]
    Duration: 4 hours 56 minutes

    4. Rollout¹ Bar/22 8/2* eq:-0.609 (-0.029)
    Player: 37.59% (G:8.55% B:0.34%)
    Opponent: 62.41% (G:24.04% B:2.44%)
    Confidence: ±0.010 (-0.619..-0.599) - [0.0%]
    Duration: 6 hours 41 minutes

    ¹ 5484 Games rolled with Variance Reduction.
    Moves: 3-ply, cube decisions: XG Roller

    eXtreme Gammon Version: 2.10


    /**************************
    /variant
    /**************************

    XGID=-----bD-C--AdD---d-c-b--BA:0:0:1:63:0:0:3:0:10

    X:Player 1 O:Player 2
    Score is X:0 O:0. Unlimited Game, Jacoby Beaver
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X O | | O O X |
    | X O | | O O X |
    | X O | | O |
    | X O | | |
    | | X | |
    | |BAR| |
    | | | |
    | O | | X |
    | O X | | X |
    | O X | | X O |
    | O X X | | X O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 184 O: 150 X-O: 0-0
    Cube: 1
    X to play 63

    1. Rollout¹ Bar/22 13/7 eq:-0.818
    Player: 34.19% (G:6.17% B:0.27%)
    Opponent: 65.81% (G:26.53% B:2.93%)
    Confidence: ±0.021 (-0.839..-0.797) - [99.8%]
    Duration: 7 minutes 09 seconds

    2. Rollout¹ Bar/16 eq:-0.860 (-0.042)
    Player: 33.36% (G:5.67% B:0.23%)
    Opponent: 66.64% (G:26.21% B:2.26%)
    Confidence: ±0.018 (-0.878..-0.841) - [0.2%]
    Duration: 6 minutes 35 seconds

    3. XG Roller++ Bar/22 24/18 eq:-0.888 (-0.070)
    Player: 33.87% (G:5.61% B:0.17%)
    Opponent: 66.13% (G:27.40% B:2.05%)

    4. XG Roller++ Bar/22 8/2 eq:-0.969 (-0.151)
    Player: 31.54% (G:5.52% B:0.18%)
    Opponent: 68.46% (G:25.74% B:2.38%)


    ¹ 1296 Games rolled with Variance Reduction.
    Moves: 3-ply, cube decisions: XG Roller


    eXtreme Gammon Version: 2.10




    --
    Ah....Clem
    The future is fun, the future is fair.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Timothy Chow@21:1/5 to ah....Clem on Fri Aug 26 21:23:31 2022
    On 8/26/2022 4:07 PM, ah....Clem wrote:
    My take was that all four options seemed playable, so I invoked Pottle's
    law to settle on bar/16.  That's favored by the rollout,  but only at
    the 91% confidence level after 5484 games.

    I can't say I understand why Pottle's law works as often as it does.

    I hate to sound like a card-carrying member of Stick's Terminology
    Police, but this really isn't an example of Pottle's law. Pottle's
    law says, "Always run the last checker." Bar/16 does not run the last
    checker.

    Pottle's law is generally taken to apply when you have only one checker
    back, but even if you stretched the meaning and tried to apply it here,
    it would refer to bar/22 24/18 and not bar/16, since the checker on the
    22pt cannot be called the "last checker" when there are two checkers on
    the 24pt.

    ---
    Tim Chow

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  • From ah...Clem@21:1/5 to Timothy Chow on Sat Aug 27 10:09:19 2022
    On 8/26/2022 9:23 PM, Timothy Chow wrote:
    On 8/26/2022 4:07 PM, ah....Clem wrote:
    My take was that all four options seemed playable, so I invoked
    Pottle's law to settle on bar/16.  That's favored by the rollout,  but
    only at the 91% confidence level after 5484 games.

    I can't say I understand why Pottle's law works as often as it does.

    I hate to sound like a card-carrying member of Stick's Terminology
    Police, but this really isn't an example of Pottle's law.  Pottle's
    law says, "Always run the last checker."  Bar/16 does not run the last checker.

    Pottle's law is generally taken to apply when you have only one checker
    back, but even if you stretched the meaning and tried to apply it here,
    it would refer to bar/22 24/18 and not bar/16, since the checker on the
    22pt cannot be called the "last checker" when there are two checkers on
    the 24pt.

    I seem to recall reading somewhere that Pottle's law said "Unless you
    have something constructive to do elsewhere, pick up the rearmost
    checker and run it as far as you can."

    But I can't find that now, and "last" is not the same as "rearmost", so
    I stand corrected.

    I'm wondering if the variant above has some general validity. For now,
    we can call it the "Generalized Pottle Hypothesis". Clearly, there are
    many exceptions.

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  • From Timothy Chow@21:1/5 to ah...Clem on Sat Aug 27 14:31:13 2022
    On 8/27/2022 10:09 AM, ah...Clem wrote:
    I seem to recall reading somewhere that Pottle's law said "Unless you
    have something constructive to do elsewhere, pick up the rearmost
    checker and run it as far as you can."

    But I can't find that now, and "last" is not the same as "rearmost", so
    I stand corrected.

    I'm wondering if the variant above has some general validity. For now,
    we can call it the "Generalized Pottle Hypothesis". Clearly, there are
    many exceptions.

    IMO, Pottle's law as usually conceived (with only one checker back) is
    backed by two general strategic ideas.

    1. If you're ahead or equal in the pip count, and your opponent has one
    or more checkers back, then you typically gain a lot by converting to a position in which you have no checkers back. This potential gain is
    usually worth exposing your last checker to a double shot, or sometimes
    even a triple shot.

    2. If you're equal or behind in the pip count, and your opponent has no checkers back, it can sometimes still be right to run the last checker
    in order to cut your losses (either single or gammon losses), because a
    lone checker is usually vulnerable to attack.

    I think that #1 is the more common scenario. What I often see are
    players who are afraid to run the last checker into a double shot,
    because they underestimate how much they gain if they are missed and
    they also underestimate the danger of having their last checker
    trapped and/or attacked.

    In terms of generalization, jumping into the opponent's outfield into a
    double or triple shot is something that I see a lot of players balking
    at, even when it is urgent that they do so. But, I wouldn't call this
    a "Generalized Pottle Hypothesis" because the underlying principle is
    not the same as for the usual Pottle's law.

    ---
    Tim Chow

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