• Midgame blitz cube action

    From Timothy Chow@21:1/5 to All on Fri Apr 14 07:42:21 2023
    XGID=a-BBB-BbB---baa-Ab-bbCbA--:1:1:1:00:0:0:0:0:10

    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 X O X |
    | O | | O O X O |
    | | | X |
    | | | |
    | | | |
    | |BAR| |
    | | O | |
    | | | |
    | | | | +---+
    | O X O | | X X X X | | 2 |
    | O X O | | X X X X | +---+
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 148 O: 154 X-O: 0-0
    Cube: 2, X own cube
    X on roll, cube action

    ---
    Tim Chow

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Timothy Chow@21:1/5 to All on Sun Apr 16 18:10:14 2023
    XGID=a-BBB-BbB---baa-Ab-bbCbA--:1:1:1:00:0:0:0:0:10

    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 X O X |
    | O | | O O X O |
    | | | X |
    | | | |
    | | | |
    | |BAR| |
    | | O | |
    | | | |
    | | | | +---+
    | O X O | | X X X X | | 2 |
    | O X O | | X X X X | +---+
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 148 O: 154 X-O: 0-0
    Cube: 2, X own cube
    X on roll, cube action

    O has a checker on the bar against a four-point board, and X is
    shooting at two more blots. This seemed like a clear redouble
    to me. But XG begs to differ. It's a little hard for me to see
    why XG thinks this redouble is such a big mistake. A hit and a
    dance certainly loses X's market by a country mile, but I think
    the trouble is that the less favorable exchanges are pretty bad.
    There's certainly a 44 anti-joker, but even an "ordinary" miss,
    followed by X getting hit back, would be very bad for X. Also,
    if X hits and O enters one checker, it won't usually lose X's
    market.

    In the variant, I have shifted X's outfield blot by a pip, and
    XG favors redoubling.

    Analyzed in Rollout
    No redouble
    Player Winning Chances: 57.74% (G:37.42% B:2.26%)
    Opponent Winning Chances: 42.26% (G:11.42% B:0.55%)
    Redouble/Take
    Player Winning Chances: 57.96% (G:37.61% B:2.46%)
    Opponent Winning Chances: 42.04% (G:11.42% B:0.54%)

    Cubeful Equities:
    No redouble: +0.625
    Redouble/Take: +0.535 (-0.090)
    Redouble/Pass: +1.000 (+0.375)

    Best Cube action: No redouble / Take
    Percentage of wrong pass needed to make the double decision right: 19.4%

    Rollout:
    1296 Games rolled with Variance Reduction.
    Dice Seed: 271828
    Moves: 3-ply, cube decisions: XG Roller
    Confidence No Double: ± 0.014 (+0.612..+0.639)
    Confidence Double: ± 0.024 (+0.511..+0.560)

    eXtreme Gammon Version: 2.19.211.pre-release

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

    XGID=a-BBB-BbB---baaA-b-bbCbA--:0:0:1:00:0:0:0:0:10

    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 X O X |
    | O | | O O X O |
    | | | X |
    | | | |
    | | | |
    | |BAR| |
    | | O | |
    | | | |
    | | | |
    | O X O | | X X X X |
    | O X O | | X X X X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 147 O: 154 X-O: 0-0
    Cube: 1
    X on roll, cube action

    Analyzed in Rollout
    No double
    Player Winning Chances: 60.21% (G:39.58% B:2.25%)
    Opponent Winning Chances: 39.79% (G:10.80% B:0.57%)
    Double/Take
    Player Winning Chances: 60.44% (G:39.94% B:2.40%)
    Opponent Winning Chances: 39.56% (G:10.91% B:0.59%)

    Cubeful Equities:
    No double: +0.638 (-0.060)
    Double/Take: +0.699
    Double/Pass: +1.000 (+0.301)

    Best Cube action: Double / Take

    Rollout:
    1296 Games rolled with Variance Reduction.
    Dice Seed: 271828
    Moves: 3-ply, cube decisions: XG Roller
    Confidence No Double: ± 0.016 (+0.623..+0.654)
    Confidence Double: ± 0.023 (+0.676..+0.721)

    eXtreme Gammon Version: 2.19.211.pre-release

    ---
    Tim Chow

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