• I have to hit, don't I?

    From Timothy Chow@21:1/5 to All on Tue Aug 16 09:16:15 2022
    XGID=--CA--EBB-a--B-ba-ab-bbbb-:0:0:1:32:0:0:0:0:10

    X:Player 1 O:Player 2
    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X O O O | | O O O O O |
    | X O | | O O O O O |
    | | | |
    | | | |
    | | | |
    | |BAR| |
    | | | X |
    | | | X |
    | | | X X |
    | X X | | X X |
    | O X X | | X X X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 95 O: 83 X-O: 0-0
    Cube: 1
    X to play 32

    ---
    Tim Chow

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From ah....Clem@21:1/5 to Timothy Chow on Tue Aug 16 14:18:59 2022
    On 8/16/2022 9:16 AM, Timothy Chow wrote:
    XGID=--CA--EBB-a--B-ba-ab-bbbb-:0:0:1:32:0:0:0:0:10

    X:Player 1   O:Player 2
    Score is X:0 O:0. Unlimited Game
     +13-14-15-16-17-18------19-20-21-22-23-24-+
     | X     O  O     O |   | O     O  O  O  O |
     | X     O          |   | O     O  O  O  O |
     |                  |   |                  |
     |                  |   |                  |
     |                  |   |                  |
     |                  |BAR|                  |
     |                  |   | X                |
     |                  |   | X                |
     |                  |   | X           X    |
     |             X  X |   | X           X    |
     |       O     X  X |   | X        X  X    |
     +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count  X: 95  O: 83 X-O: 0-0
    Cube: 1
    X to play 32


    O has a cube whether X hits or not, but it looks like X has a take after
    making the five point and a pass if O is shooting at a blot from the bar
    with a five point board.

    So I'll just make the five point.


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

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Stick Rice@21:1/5 to ah....Clem on Tue Aug 16 11:25:15 2022
    On Tuesday, August 16, 2022 at 2:18:59 PM UTC-4, ah....Clem wrote:
    On 8/16/2022 9:16 AM, Timothy Chow wrote:
    XGID=--CA--EBB-a--B-ba-ab-bbbb-:0:0:1:32:0:0:0:0:10

    X:Player 1 O:Player 2
    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X O O O | | O O O O O |
    | X O | | O O O O O |
    | | | |
    | | | |
    | | | |
    | |BAR| |
    | | | X |
    | | | X |
    | | | X X |
    | X X | | X X |
    | O X X | | X X X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 95 O: 83 X-O: 0-0
    Cube: 1
    X to play 32
    O has a cube whether X hits or not, but it looks like X has a take after making the five point and a pass if O is shooting at a blot from the bar with a five point board.

    So I'll just make the five point.


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

    No way it's a drop after hitting and continuing 13/8. We leave 13 shots of which we lose ~11 games. The other 23 games we win 12(?) So overall 14 games. While gammons are possible they really only occur when we're hit immediately with a three in
    those original 11 games we lose. We lose a gammon maybe half those games? 15% of the time. Easy take.

    Stick

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Timothy Chow@21:1/5 to All on Thu Aug 18 08:26:30 2022
    XGID=--CA--EBB-a--B-ba-ab-bbbb-:0:0:1:32:0:0:0:0:10

    X:Player 1 O:Player 2
    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X O O O | | O O O O O |
    | X O | | O O O O O |
    | | | |
    | | | |
    | | | |
    | |BAR| |
    | | | X |
    | | | X |
    | | | X X |
    | X X | | X X |
    | O X X | | X X X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 95 O: 83 X-O: 0-0
    Cube: 1
    X to play 32

    Yes, I have to hit, despite the blot in my board and O's five-point
    board. If I don't hit, then it's almost certainly going to be just
    a race, and even without a sophisticated racing formula, you can
    probably guess that X will win only about 25-35% of the time. If
    X hits then he will certainly win more often than that, so the
    question is whether the hit loses too many gammons. According to
    the rollout below, it's not remotely close.

    Interestingly, XG 3-ply plays 8/5 7/5 here, although it recognizes
    the error of its ways if you force it to evaluate 13/10*/8 at 3-ply.

    In the variant, I have given O her strongest five-point board, and
    now 13/10*/8 and 8/5 7/5 are tied---but this has more to do with the
    fact that racing with 8/5 7/5 is now a more promising plan than with
    X losing more gammons when he hits.

    1. Rollout¹ 13/10* 10/8 eq:-0.354
    Player: 40.30% (G:1.24% B:0.03%)
    Opponent: 59.70% (G:15.18% B:0.17%)
    Confidence: ±0.012 (-0.366..-0.342) - [100.0%]

    2. Rollout¹ 13/10* 3/1 eq:-0.622 (-0.268)
    Player: 37.60% (G:1.43% B:0.04%)
    Opponent: 62.40% (G:21.89% B:0.56%)
    Confidence: ±0.012 (-0.634..-0.610) - [0.0%]

    3. Rollout¹ 8/5 7/5 eq:-0.670 (-0.316)
    Player: 28.76% (G:0.11% B:0.00%)
    Opponent: 71.24% (G:0.46% B:0.01%)
    Confidence: ±0.008 (-0.678..-0.661) - [0.0%]

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

    eXtreme Gammon Version: 2.19.207.pre-release

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

    XGID=--CA--EBB-a--B-ba-abbbbb--:0:0:1:32:0:0:0:0:10

    X:Player 1 O:Player 2
    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X O O O | | O O O O O |
    | X O | | O O O O O |
    | | | |
    | | | |
    | | | |
    | |BAR| |
    | | | X |
    | | | X |
    | | | X X |
    | X X | | X X |
    | O X X | | X X X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 95 O: 91 X-O: 0-0
    Cube: 1
    X to play 32

    1. Rollout¹ 13/10* 10/8 eq:-0.232
    Player: 43.33% (G:0.92% B:0.02%)
    Opponent: 56.67% (G:16.97% B:0.26%)
    Confidence: ±0.008 (-0.240..-0.224) - [62.0%]

    2. Rollout¹ 8/5 7/5 eq:-0.234 (-0.002)
    Player: 41.90% (G:0.06% B:0.00%)
    Opponent: 58.10% (G:0.28% B:0.01%)
    Confidence: ±0.005 (-0.239..-0.228) - [37.8%]

    3. Rollout¹ 7/5 7/4 eq:-0.243 (-0.011)
    Player: 41.65% (G:0.08% B:0.00%)
    Opponent: 58.35% (G:0.46% B:0.02%)
    Confidence: ±0.005 (-0.248..-0.238) - [0.1%]

    4. Rollout¹ 7/4 6/4 eq:-0.243 (-0.011)
    Player: 41.34% (G:0.05% B:0.00%)
    Opponent: 58.66% (G:0.22% B:0.01%)
    Confidence: ±0.006 (-0.249..-0.238) - [0.1%]

    ¹ 2592 Games rolled with Variance Reduction.
    Dice Seed: 271828
    Moves: 3-ply, cube decisions: XG Roller

    eXtreme Gammon Version: 2.19.207.pre-release

    ---
    Tim Chow

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)