• Time to go?

    From Timothy Chow@21:1/5 to All on Thu Aug 17 09:59:14 2023
    XGID=-BBBBBB-A-----------d-edB-:1:1:1:51:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | | | O O O X |
    | | | O O O X |
    | | | O O O |
    | | | O O O |
    | | | O |
    | |BAR| |
    | | | |
    | | | |
    | | | | +---+
    | | | X X X X X X | | 2 |
    | X | | X X X X X X | +---+
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 98 O: 43 X-O: 0-0
    Cube: 2, X own cube
    X to play 51

    ---
    Tim Chow

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From ah....Clem@21:1/5 to Timothy Chow on Thu Aug 17 14:44:37 2023
    On 8/17/2023 9:59 AM, Timothy Chow wrote:
    XGID=-BBBBBB-A-----------d-edB-:1:1:1:51:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
     +13-14-15-16-17-18------19-20-21-22-23-24-+
     |                  |   |    O     O  O  X |
     |                  |   |    O     O  O  X |
     |                  |   |    O     O  O    |
     |                  |   |    O     O  O    |
     |                  |   |          O       |
     |                  |BAR|                  |
     |                  |   |                  |
     |                  |   |                  |
     |                  |   |                  | +---+
     |                  |   | X  X  X  X  X  X | | 2 |
     |             X    |   | X  X  X  X  X  X | +---+
     +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count  X: 98  O: 43 X-O: 0-0
    Cube: 2, X own cube
    X to play 51


    I think so. X needs to maintain the board and it looks like there are
    too many rolls that prevent him from breaking anchor next roll to
    justify staying. He'll be running off the anchor soon enough anyway, so
    not much to lose by doing it now.

    24/18 looks better than 24/19 8/7 since it makes a crossover, and X can
    still save gammon.

    --
    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 All on Sat Aug 19 08:54:40 2023
    XGID=-BBBBBB-A-----------d-edB-:1:1:1:51:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | | | O O O X |
    | | | O O O X |
    | | | O O O |
    | | | O O O |
    | | | O |
    | |BAR| |
    | | | |
    | | | |
    | | | | +---+
    | | | X X X X X X | | 2 |
    | X | | X X X X X X | +---+
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 98 O: 43 X-O: 0-0
    Cube: 2, X own cube
    X to play 51

    This should have been an easy decision but I muffed it anyway. Playing
    8/2 wastes pips for the gammon race. You might worry, as I did, that
    running off the anchor will leave the straggler vulnerable to attack.
    While that is possible, the other thing that running off the anchor
    does is to force O to expose a blot immediately with 64 54 or 43.

    In the variant, X's outfield blot is on his 16pt. This poses a more
    subtle problem. Now 16/10 doesn't waste any pips, and is better for
    getting off the gammon, but 24/18 or 24/19 16/15 is still better for
    the win because it gives O a playable 4. According to the rollout,
    these two factors almost exactly balance each other out.

    1. Rollout¹ 24/19 8/7 eq:-0.796
    Player: 14.43% (G:0.00% B:0.00%)
    Opponent: 85.57% (G:12.57% B:0.26%)
    Confidence: ±0.002 (-0.798..-0.794) - [94.5%]

    2. Rollout¹ 24/18 eq:-0.798 (-0.003)
    Player: 14.27% (G:0.00% B:0.00%)
    Opponent: 85.73% (G:12.40% B:0.25%)
    Confidence: ±0.002 (-0.801..-0.796) - [5.5%]

    3. Rollout¹ 8/2 eq:-0.924 (-0.128)
    Player: 10.80% (G:0.00% B:0.00%)
    Opponent: 89.20% (G:17.67% B:0.64%)
    Confidence: ±0.003 (-0.927..-0.921) - [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=-BBBBBB---------A---d-edB-:1:1:1:51:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X | | O O O X |
    | | | O O O X |
    | | | O O O |
    | | | O O O |
    | | | O |
    | |BAR| |
    | | | |
    | | | |
    | | | | +---+
    | | | X X X X X X | | 2 |
    | | | X X X X X X | +---+
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 106 O: 43 X-O: 0-0
    Cube: 2, X own cube
    X to play 51

    1. Rollout¹ 16/10 eq:-0.918
    Player: 13.50% (G:0.00% B:0.00%)
    Opponent: 86.50% (G:22.68% B:0.91%)
    Confidence: ±0.002 (-0.920..-0.916) - [89.5%]

    2. Rollout¹ 24/18 eq:-0.920 (-0.002)
    Player: 15.26% (G:0.00% B:0.00%)
    Opponent: 84.74% (G:26.41% B:0.54%)
    Confidence: ±0.002 (-0.921..-0.918) - [7.2%]

    3. Rollout² 24/19 16/15 eq:-0.920 (-0.003)
    Player: 15.35% (G:0.00% B:0.00%)
    Opponent: 84.65% (G:26.69% B:0.54%)
    Confidence: ±0.002 (-0.922..-0.918) - [3.3%]

    ¹ 2592 Games rolled with Variance Reduction.
    Dice Seed: 271828
    Moves: 4-ply, cube decisions: XG Roller+
    Search interval: Large

    ² 1296 Games rolled with Variance Reduction.
    Dice Seed: 271828
    Moves: 4-ply, cube decisions: XG Roller+
    Search interval: Large

    eXtreme Gammon Version: 2.19.211.pre-release

    ---
    Tim Chow

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