• 3pt or 8pt?

    From Timothy Chow@21:1/5 to All on Fri Aug 4 09:05:04 2023
    XGID=--a--BECA---cBb--bBe-b----:0:0:1:53:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X O O X | | O O |
    | X O O X | | O O |
    | | | O |
    | | | O |
    | | | O |
    | |BAR| |
    | | | X |
    | | | X |
    | O X | | X |
    | O X | | X X |
    | O X X | | X X O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 131 O: 138 X-O: 0-0
    Cube: 1
    X to play 53

    ---
    Tim Chow

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Timothy Chow@21:1/5 to All on Sun Aug 6 09:29:01 2023
    XGID=--a--BECA---cBb--bBe-b----:0:0:1:53:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X O O X | | O O |
    | X O O X | | O O |
    | | | O |
    | | | O |
    | | | O |
    | |BAR| |
    | | | X |
    | | | X |
    | O X | | X |
    | O X | | X X |
    | O X X | | X X O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 131 O: 138 X-O: 0-0
    Cube: 1
    X to play 53

    The "3pt or 8pt" decision has some similarities with the "4pt or 7pt"
    decision. Here, the 8pt is six pips away from O's straggler, and so
    is a useful blocking point. Making the 3pt is better for attacking,
    and it also unstacks the heavy 6pt. Nevertheless, XG says that
    making the 3pt is a whopper with cheese. In part this is because
    13/10 13/8 gives X three builders for making his 4pt, which would
    give him a solid five-prime. In the variant, I have stacked another
    checker on X's 6pt and you can see the effect on the rollout.

    1. Rollout¹ 13/10 13/8 eq:+0.607
    Player: 63.87% (G:18.36% B:0.39%)
    Opponent: 36.13% (G:6.08% B:0.24%)
    Confidence: ±0.013 (+0.594..+0.621) - [100.0%]

    2. Rollout¹ 13/8 6/3 eq:+0.496 (-0.112)
    Player: 61.07% (G:18.28% B:0.52%)
    Opponent: 38.93% (G:8.90% B:0.38%)
    Confidence: ±0.013 (+0.482..+0.509) - [0.0%]

    3. Rollout¹ 8/3 6/3 eq:+0.461 (-0.146)
    Player: 61.18% (G:15.99% B:0.32%)
    Opponent: 38.82% (G:5.48% B:0.23%)
    Confidence: ±0.011 (+0.450..+0.472) - [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=--a--BFBA---cBb--bBe-b----:0:0:1:53:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X O O X | | O O |
    | X O O X | | O O |
    | | | O |
    | | | O |
    | | | O |
    | |BAR| |
    | | | 6 |
    | | | X |
    | O | | X |
    | O X | | X X |
    | O X X | | X X O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 130 O: 138 X-O: 0-0
    Cube: 1
    X to play 53

    1. Rollout¹ 8/3 6/3 eq:+0.432
    Player: 60.42% (G:16.72% B:0.31%)
    Opponent: 39.58% (G:6.07% B:0.25%)
    Confidence: ±0.006 (+0.426..+0.439) - [76.3%]

    2. Rollout¹ 13/10 13/8 eq:+0.429 (-0.003)
    Player: 60.41% (G:16.02% B:0.31%)
    Opponent: 39.59% (G:6.79% B:0.27%)
    Confidence: ±0.006 (+0.424..+0.435) - [23.7%]

    ¹ 5184 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)