• Run or dump?

    From Timothy Chow@21:1/5 to All on Mon Aug 8 09:38:08 2022
    XGID=--A-CACbC-a-aB-a---bbbbbB-:1:1:1:65:0:0:0:0:10

    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 X |
    | X | | O O O O O X |
    | | | |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | X | | X X | +---+
    | X O | | X X | | 2 |
    | O O X O | | X X X X | +---+
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 135 O: 114 X-O: 0-0
    Cube: 2, X own cube
    X to play 65

    ---
    Tim Chow

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From ah...Clem@21:1/5 to Timothy Chow on Mon Aug 8 11:37:20 2022
    On 8/8/2022 9:38 AM, Timothy Chow wrote:
    XGID=--A-CACbC-a-aB-a---bbbbbB-:1:1:1:65:0:0:0:0:10

    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  X |
     | X                |   | O  O  O  O  O  X |  |                  |   |                  |
     |                  |   |                  |
     |                  |   |                  |
     |                  |BAR|                  |
     |                  |   |                  |
     |                  |   |                  |
     |             X    |   | X     X          | +---+
     |             X  O |   | X     X          | | 2 |
     | O     O     X  O |   | X  X  X     X    | +---+  +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count  X: 135  O: 114 X-O: 0-0
    Cube: 2, X own cube
    X to play 65

    If X runs, what's next? There's still a blot on the ace stuck behind a
    five prime and O can hit loose unless X fixes his board. If X dumps,
    what's next? He loses timing for the holding game. That seems worse, so
    I'll run. Not sure at all.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Timothy Chow@21:1/5 to All on Wed Aug 10 08:52:21 2022
    XGID=--A-CACbC-a-aB-a---bbbbbB-:1:1:1:65:0:0:0:0:10

    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 X |
    | X | | O O O O O X |
    | | | |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | X | | X X | +---+
    | X O | | X X | | 2 |
    | O O X O | | X X X X | +---+
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 135 O: 114 X-O: 0-0
    Cube: 2, X own cube
    X to play 65

    It makes a difference how ugly X's board is before and after the dumping
    play. X's board is ugly here but 8/2 6/1 is not much of an improvement.
    I constructed a variant below in which the dumping play significantly
    improves X's board.

    1. Rollout¹ 24/13 eq:-0.721
    Player: 22.85% (G:5.64% B:0.24%)
    Opponent: 77.15% (G:31.81% B:0.48%)
    Confidence: ±0.007 (-0.729..-0.714) - [100.0%]

    2. Rollout¹ 8/2 6/1 eq:-0.833 (-0.112)
    Player: 16.86% (G:3.26% B:0.07%)
    Opponent: 83.14% (G:24.33% B:1.45%)
    Confidence: ±0.006 (-0.839..-0.827) - [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=-AA-BACbC-a-aB-a---bbbbbB-:1:1:1:65:0:0:0:0:10

    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 X |
    | X | | O O O O O X |
    | | | |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | X | | X | +---+
    | X O | | X X | | 2 |
    | O O X O | | X X X X X | +---+
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 132 O: 114 X-O: 0-0
    Cube: 2, X own cube
    X to play 65

    XG 3-ply still plays 24/13 here, but the rollout favors 8/2 6/1.

    1. Rollout¹ 8/2 6/1 eq:-0.761
    Player: 19.20% (G:4.22% B:0.07%)
    Opponent: 80.80% (G:24.36% B:1.28%)
    Confidence: ±0.006 (-0.767..-0.755) - [100.0%]

    2. Rollout¹ 24/13 eq:-0.815 (-0.054)
    Player: 19.69% (G:6.04% B:0.18%)
    Opponent: 80.31% (G:34.04% B:0.70%)
    Confidence: ±0.007 (-0.822..-0.808) - [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

    ---
    Tim Chow

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