• Time to break anchor?

    From Timothy Chow@21:1/5 to All on Wed Nov 15 22:58:57 2023
    XGID=-BBBCbB-B-----b----cBbcba-:0:0:1:42:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | O | | O X O O O O |
    | O | | O X O O O |
    | | | O O |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | | | X |
    | X | | X O X X X X |
    | X | | X O X X X X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 92 O: 102 X-O: 0-0
    Cube: 1
    X to play 42

    ---
    Tim Chow

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Timothy Chow@21:1/5 to All on Fri Nov 17 09:33:54 2023
    XGID=-BBBCbB-B-----b----cBbcba-:0:0:1:42:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | O | | O X O O O O |
    | O | | O X O O O |
    | | | O O |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | | | X |
    | X | | X O X X X X |
    | X | | X O X X X X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 92 O: 102 X-O: 0-0
    Cube: 1
    X to play 42

    The question here is whether 20/18 20/16 is justified on account of
    O's home-board blot and the duplication of 2's. XG 3-ply actually
    favors 8/6 8/4 here, but the rollout disagrees. It's interesting to
    explore different variants here; one is shown below.

    1. Rollout¹ 20/18 20/16 eq:-0.074
    Player: 48.16% (G:12.23% B:0.33%)
    Opponent: 51.84% (G:15.67% B:0.32%)
    Confidence: ±0.008 (-0.082..-0.065) - [100.0%]

    2. Rollout¹ 8/6 8/4 eq:-0.162 (-0.088)
    Player: 46.17% (G:8.02% B:0.18%)
    Opponent: 53.83% (G:7.89% B:0.20%)
    Confidence: ±0.009 (-0.171..-0.153) - [0.0%]

    ¹ 1296 Games rolled with Variance Reduction.
    Dice Seed: 271828
    Moves: 3-ply, cube decisions: XG Roller

    eXtreme Gammon Version: 2.19.211.pre-release

    -------
    Variant
    -------

    XGID=-BBBCbB-B-----b----cBbcc--:0:0:1:42:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | O | | O X O O O |
    | O | | O X O O O |
    | | | O O O |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | | | X |
    | X | | X O X X X X |
    | X | | X O X X X X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 92 O: 103 X-O: 0-0
    Cube: 1
    X to play 42

    1. Rollout¹ 8/6 8/4 eq:-0.130
    Player: 47.06% (G:7.59% B:0.14%)
    Opponent: 52.94% (G:7.39% B:0.18%)
    Confidence: ±0.009 (-0.139..-0.120) - [92.4%]

    2. Rollout¹ 20/18 20/16 eq:-0.138 (-0.009)
    Player: 47.54% (G:8.08% B:0.17%)
    Opponent: 52.46% (G:12.52% B:0.25%)
    Confidence: ±0.007 (-0.146..-0.131) - [7.6%]

    ¹ 1296 Games rolled with Variance Reduction.
    Dice Seed: 271828
    Moves: 3-ply, cube decisions: XG Roller

    eXtreme Gammon Version: 2.19.211.pre-release

    ---
    Tim Chow

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From ah...Clem@21:1/5 to Timothy Chow on Fri Nov 17 10:29:53 2023
    On 11/15/2023 10:58 PM, Timothy Chow wrote:
    XGID=-BBBCbB-B-----b----cBbcba-:0:0:1:42:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game  +13-14-15-16-17-18------19-20-21-22-23-24-+
     |    O             |   | O  X  O  O  O  O |
     |    O             |   | O  X  O  O  O    |  |                  |   | O        O       |  |                  |   |                  |
     |                  |   |                  |
     |                  |BAR|                  |
     |                  |   |                  |
     |                  |   |                  |
     |                  |   |       X          |
     |             X    |   | X  O  X  X  X  X |  |             X    |   | X  O  X  X  X  X |  +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count  X: 92  O: 102 X-O: 0-0
    Cube: 1
    X to play 42


    I'm trying to come up with a reason to bun off the anchor and coming up
    short. OTB I'd clear the eight point without much thought. Further
    thinking doesn't override that.

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    * Origin: fsxNet Usenet Gateway (21:1/5)