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  • Time to attack?

    From Timothy Chow@21:1/5 to All on Fri Nov 17 09:34:58 2023
    XGID=-a-BBCCB----b--b-dbdB--A--:1:-1:1:65:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | O O O | | O X X | +---+
    | O O O | | O X | | 2 |
    | O | | O | +---+
    | O | | O |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | | | X X |
    | O X | | X X X X |
    | O X | | X X X X O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 124 O: 140 X-O: 0-0
    Cube: 2, O 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 Fri Nov 17 10:39:45 2023
    On 11/17/2023 9:34 AM, Timothy Chow wrote:
    XGID=-a-BBCCB----b--b-dbdB--A--:1:-1:1:65:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game  +13-14-15-16-17-18------19-20-21-22-23-24-+
     |       O     O  O |   | O  X        X    | +---+  |       O     O  O |   | O  X             | | 2 |  |             O    |   | O                | +---+
     |             O    |   | O                |  |                  |   |                  |
     |                  |BAR|                  |
     |                  |   |                  |
     |                  |   |                  |
     |                  |   | X  X             |  | O              X |   | X  X  X  X       |
     | O              X |   | X  X  X  X     O |  +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count  X: 124  O: 140 X-O: 0-0
    Cube: 2, O own cube
    X to play 65

    X is ahead in the race, so simply running is thematic - there's no
    compelling reason to attack on the ace point.

    EXCEPT: running off the anchor leaves a whole bunch of shots. Maybe the
    solid five prime with O not at the edge makes offering up a near certain
    trip to the roof worth it, but I'm not seeing it.

    Hit loose and run? Might be the goldilocks play, but I'll POH on the ace.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Timothy Chow@21:1/5 to All on Sun Nov 19 15:16:01 2023
    XGID=-a-BBCCB----b--b-dbdB--A--:1:-1:1:65:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | O O O | | O X X | +---+
    | O O O | | O X | | 2 |
    | O | | O | +---+
    | O | | O |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | | | X X |
    | O X | | X X X X |
    | O X | | X X X X O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 124 O: 140 X-O: 0-0
    Cube: 2, O own cube
    X to play 65

    When we have a five-prime and the opponent has a straggler behind it
    that is not at the edge of a prime, it's often best to leave the prime
    intact rather than break our five-prime to attack it. However, here,
    the only plausible play that doesn't hit is to break our golden anchor
    in front our our opponent's stacks. It's interesting to compare this
    position with Variant 2 below, where we have a 4pt anchor instead.

    Once we decide to hit with 6/1*, there remains the question whether to
    cover with 7/1 or jump out with 20/14. I'm not sure exactly how to
    assess this decision, especially in light of Variant 1 below.

    1. Rollout¹ 7/1* 6/1 eq:+0.473
    Player: 64.73% (G:38.33% B:0.21%)
    Opponent: 35.27% (G:5.59% B:0.29%)
    Confidence: ±0.010 (+0.463..+0.483) - [100.0%]

    2. Rollout¹ 20/14 6/1* eq:+0.413 (-0.059)
    Player: 63.82% (G:36.73% B:0.67%)
    Opponent: 36.18% (G:8.16% B:0.50%)
    Confidence: ±0.010 (+0.403..+0.424) - [0.0%]

    3. Rollout¹ 20/9 eq:+0.319 (-0.154)
    Player: 61.80% (G:31.68% B:1.02%)
    Opponent: 38.20% (G:8.51% B:0.42%)
    Confidence: ±0.010 (+0.309..+0.328) - [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 1
    ---------

    XGID=-a-BCBCB----b--b-dbdB--A--:1:-1:1:65:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | O O O | | O X X | +---+
    | O O O | | O X | | 2 |
    | O | | O | +---+
    | O | | O |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | | | X X |
    | O X | | X X X X |
    | O X | | X X X X O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 123 O: 140 X-O: 0-0
    Cube: 2, O own cube
    X to play 65

    1. Rollout¹ 20/14 6/1* eq:+0.410
    Player: 63.50% (G:36.94% B:0.78%)
    Opponent: 36.50% (G:8.39% B:0.53%)
    Confidence: ±0.010 (+0.400..+0.420) - [76.0%]

    2. Rollout¹ 7/1* 6/1 eq:+0.405 (-0.005)
    Player: 62.95% (G:35.87% B:0.22%)
    Opponent: 37.05% (G:5.86% B:0.28%)
    Confidence: ±0.011 (+0.394..+0.415) - [24.0%]

    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 2
    ---------

    XGID=-a-BBCCB----b--b-dbd-B-A--:1:-1:1:65:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | O O O | | O X X | +---+
    | O O O | | O X | | 2 |
    | O | | O | +---+
    | O | | O |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | | | X X |
    | O X | | X X X X |
    | O X | | X X X X O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 126 O: 140 X-O: 0-0
    Cube: 2, O own cube
    X to play 65

    1. Rollout¹ 21/10 eq:+0.335
    Player: 62.32% (G:31.52% B:0.72%)
    Opponent: 37.68% (G:8.17% B:0.41%)
    Confidence: ±0.010 (+0.326..+0.345) - [100.0%]

    2. Rollout¹ 7/1* 6/1 eq:+0.209 (-0.127)
    Player: 57.63% (G:31.10% B:0.19%)
    Opponent: 42.37% (G:6.97% B:0.30%)
    Confidence: ±0.010 (+0.199..+0.218) - [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

    ---
    Tim Chow

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