• Make the bar point or step up?

    From Timothy Chow@21:1/5 to All on Wed May 24 08:38:29 2023
    Yet another problem that Stick solved purely from the subject line.

    XGID=----BbD-C-A-cDb--b-bbb--A-:0:0:1:11:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X O O | | O O O X |
    | X O O | | O O O |
    | X | | |
    | X | | |
    | | | |
    | |BAR| |
    | | | |
    | | | X |
    | O X | | X |
    | O X | | X O X |
    | O X X | | X O X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 142 O: 147 X-O: 0-0
    Cube: 1
    X to play 11

    ---
    Tim Chow

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Timothy Chow@21:1/5 to All on Fri May 26 08:30:56 2023
    XGID=----BbD-C-A-cDb--b-bbb--A-:0:0:1:11:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X O O | | O O O X |
    | X O O | | O O O |
    | X | | |
    | X | | |
    | | | |
    | |BAR| |
    | | | |
    | | | X |
    | O X | | X |
    | O X | | X O X |
    | O X X | | X O X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 142 O: 147 X-O: 0-0
    Cube: 1
    X to play 11

    The bar point has diminished value when O has the golden anchor.
    But X also has to consider the risk of being attacked if he steps
    up. O doesn't have a lot of attackers in position, so XG says that
    stepping up is the way to go. But see the variant for comparison.

    1. Rollout¹ 24/22 10/8 eq:-0.474
    Player: 39.74% (G:6.47% B:0.21%)
    Opponent: 60.26% (G:18.38% B:0.35%)
    Confidence: ±0.013 (-0.487..-0.461) - [100.0%]

    2. Rollout¹ 10/7 8/7 eq:-0.560 (-0.086)
    Player: 36.52% (G:5.30% B:0.20%)
    Opponent: 63.48% (G:15.27% B:0.35%)
    Confidence: ±0.013 (-0.573..-0.547) - [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=----BbD-C-A-cDa--c-bbb--A-:0:0:1:11:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X O O | | O O O X |
    | X O | | O O O |
    | X O | | |
    | X | | |
    | | | |
    | |BAR| |
    | | | |
    | | | X |
    | O X | | X |
    | O X | | X O X |
    | O X X | | X O X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 142 O: 144 X-O: 0-0
    Cube: 1
    X to play 11

    1. Rollout¹ 10/7 8/7 eq:-0.537
    Player: 37.08% (G:5.04% B:0.20%)
    Opponent: 62.92% (G:14.91% B:0.31%)
    Confidence: ±0.012 (-0.549..-0.525) - [93.4%]

    2. Rollout¹ 24/22 10/8 eq:-0.551 (-0.014)
    Player: 37.90% (G:5.77% B:0.21%)
    Opponent: 62.10% (G:19.48% B:0.27%)
    Confidence: ±0.013 (-0.564..-0.538) - [6.6%]

    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

    ---
    Tim Chow

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