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  • Best way to contain?

    From Timothy Chow@21:1/5 to All on Sat Nov 13 00:13:40 2021
    XGID=-BaBCBB-----b--A-bCcb-bc--:0:0:1:31:0:0:0:0:10

    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 X | | O O O O |
    | O X | | O O O O |
    | X | | O O |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | | | X |
    | O | | X X X X X |
    | O | | X X X X O X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 111 O: 105 X-O: 0-0
    Cube: 1
    X to play 31

    ---
    Tim Chow

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Timothy Chow@21:1/5 to All on Mon Nov 15 09:42:07 2021
    XGID=-BaBCBB-----b--A-bCcb-bc--:0:0:1:31:0:0:0:0:10

    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 X | | O O O O |
    | O X | | O O O O |
    | X | | O O |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | | | X |
    | O | | X X X X X |
    | O | | X X X X O X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 111 O: 105 X-O: 0-0
    Cube: 1
    X to play 31

    I chose not to leave a blot, but 18/15 4/3 leaves an inflexible
    position. If I don't get and hit a shot next turn, I could be
    the one struggling to play an awkward roll. For comparison,
    see the variant.

    1. Rollout¹ 15/11 eq:+0.149
    Player: 54.33% (G:10.64% B:0.18%)
    Opponent: 45.67% (G:8.03% B:0.13%)
    Confidence: ±0.009 (+0.140..+0.158) - [100.0%]

    2. Rollout¹ 18/15 4/3 eq:+0.066 (-0.083)
    Player: 51.94% (G:10.80% B:0.24%)
    Opponent: 48.06% (G:9.11% B:0.17%)
    Confidence: ±0.008 (+0.058..+0.075) - [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=-BBaBCB-----b--A-bCcb-bc--:0:0:1:31:0:0:0:0:10

    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 X | | O O O O |
    | O X | | O O O O |
    | X | | O O |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | | | X |
    | O | | X X X X X |
    | O | | X X X O X X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 110 O: 104 X-O: 0-0
    Cube: 1
    X to play 31

    1. Rollout¹ 18/15 5/4 eq:+0.054
    Player: 51.88% (G:9.83% B:0.16%)
    Opponent: 48.12% (G:7.06% B:0.16%)
    Confidence: ±0.009 (+0.045..+0.063) - [100.0%]

    2. Rollout¹ 15/11 eq:-0.014 (-0.068)
    Player: 49.53% (G:8.77% B:0.11%)
    Opponent: 50.47% (G:8.65% B:0.14%)
    Confidence: ±0.007 (-0.021..-0.007) - [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)
  • From Timothy Chow@21:1/5 to All on Thu Aug 18 08:27:22 2022
    XGID=-a-BB-C-BB-A-C--a--ccbcb--:0:0:1:65:0:0:0:0:10

    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 | | O O O O O |
    | X | | O O O |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | | | X |
    | X X | | X X X |
    | X X X | | X X X O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 116 O: 87 X-O: 0-0
    Cube: 1
    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 Thu Aug 18 17:39:42 2022
    On 8/18/2022 8:27 AM, Timothy Chow wrote:
    XGID=-a-BB-C-BB-A-C--a--ccbcb--:0:0:1:65:0:0:0:0:10

    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                |   | O  O  O  O  O    |
     | X                |   | O  O     O       |
     |                  |   |                  |
     |                  |   |                  |
     |                  |BAR|                  |
     |                  |   |                  |
     |                  |   |                  |
     |                  |   | X                |
     |          X  X    |   | X     X  X       |
     |    X     X  X    |   | X     X  X     O |
     +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count  X: 116  O: 87 X-O: 0-0
    Cube: 1
    X to play 65

    I don't think it's correct to expose a direct shot, but we have to leave
    an indirect. That leaves 9/3 for the six. Then a single indirect looks
    better than a double indirect shot, so 13/8 is out as the follow on.

    That leaves 11/6 or 9/4 and 9/4 looks more flexible.

    The other approach is to hit loose on the ace, but while that works
    great when it does, 13 shots is too much for my tastes against a solid
    five point board.


    --
    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 20 09:22:58 2022
    XGID=-a-BB-C-BB-A-C--a--ccbcb--:0:0:1:65:0:0:0:0:10

    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 | | O O O O O |
    | X | | O O O |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | | | X |
    | X X | | X X X |
    | X X X | | X X X O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 116 O: 87 X-O: 0-0
    Cube: 1
    X to play 65

    OTB, I reasoned as ah_clem did, playing 9/4 9/3 because I didn't
    want to leave too many indirect shots. But the XG rollout below
    says that 9/4 9/3 is a whopper. Evidently, it thinks that X should
    take a bit of a risk in order to increase his chances of making the
    5pt and/or the bar point. Since X is still 18 pips down after the
    roll, he really wants to plug those holes; otherwise, O will have
    repeated chances to escape and win the race.

    1. Rollout¹ 13/8 9/3 eq:-0.041
    Player: 47.40% (G:1.72% B:0.05%)
    Opponent: 52.60% (G:13.25% B:0.17%)
    Confidence: ±0.009 (-0.050..-0.032) - [100.0%]

    2. Rollout¹ 9/4 9/3 eq:-0.151 (-0.110)
    Player: 44.83% (G:1.33% B:0.03%)
    Opponent: 55.17% (G:11.44% B:0.16%)
    Confidence: ±0.009 (-0.160..-0.142) - [0.0%]

    3. Rollout¹ 11/6 9/3 eq:-0.235 (-0.194)
    Player: 41.37% (G:1.27% B:0.03%)
    Opponent: 58.63% (G:10.87% B:0.15%)
    Confidence: ±0.008 (-0.243..-0.227) - [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)
  • From Timothy Chow@21:1/5 to All on Tue Oct 18 08:36:35 2022
    XGID=--BCaDB--bB-----B--babbcb-:1:1:1:64:0:0:0:0:10

    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 | | O O O O O |
    | | | O |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | | | X |
    | | | X X | +---+
    | X O | | X X X X | | 2 |
    | X O | | X X O X X | +---+
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 97 O: 92 X-O: 0-0
    Cube: 2, X own cube
    X to play 64

    ---
    Tim Chow

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Timothy Chow@21:1/5 to All on Thu Oct 20 09:24:56 2022
    XGID=--BCaDB--bB-----B--babbcb-:1:1:1:64:0:0:0:0:10

    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 | | O O O O O |
    | | | O |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | | | X |
    | | | X X | +---+
    | X O | | X X X X | | 2 |
    | X O | | X X O X X | +---+
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 97 O: 92 X-O: 0-0
    Cube: 2, X own cube
    X to play 64

    Doug Zare once wrote a GammonVillage article on "Late Loose Hits."
    You can often get a surprisingly accurate estimate of the game-winning
    chances of the loose hit by pretending that you lose if the opponent
    hits back and you win otherwise. In this position, that crude heuristic
    would suggest that you win 64% of the time, which is pretty close to
    what XG says. Of course, there are also gammons to consider, and the
    state of the opponent's board matters for that. According to the
    rollouts below, you should definitely hit in this position, but if O's
    dead checker on her 2pt were on her 6pt, XG plays safe with 16/6.

    For good measure, I've also included the rollout of the decision I faced
    on the next turn.

    1. Rollout¹ 10/6 10/4* eq:+0.504
    Player: 62.14% (G:19.31% B:0.52%)
    Opponent: 37.86% (G:7.90% B:0.10%)
    Confidence: ±0.004 (+0.500..+0.509) - [100.0%]

    2. Rollout¹ 16/6 eq:+0.410 (-0.094)
    Player: 57.96% (G:7.49% B:0.40%)
    Opponent: 42.04% (G:2.90% B:0.04%)
    Confidence: ±0.007 (+0.404..+0.417) - [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=--BCaDB--bB-----B--cabbbb-:1:1:1:64:0:0:0:0:10

    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 | | O O O O O |
    | | | O |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | | | X |
    | | | X X | +---+
    | X O | | X X X X | | 2 |
    | X O | | X X O X X | +---+
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 97 O: 96 X-O: 0-0
    Cube: 2, X own cube
    X to play 64

    1. Rollout¹ 16/6 eq:+0.429
    Player: 58.83% (G:6.68% B:0.32%)
    Opponent: 41.17% (G:3.38% B:0.05%)
    Confidence: ±0.006 (+0.423..+0.435) - [100.0%]

    2. Rollout¹ 10/6 10/4* eq:+0.386 (-0.043)
    Player: 57.65% (G:17.56% B:0.45%)
    Opponent: 42.35% (G:12.22% B:0.12%)
    Confidence: ±0.005 (+0.381..+0.391) - [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

    ---------
    Next turn
    ---------

    XGID=--BCaDC--aB-----Aa-babbcb-: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 O | +---+
    | | | O O O O O | | 2 |
    | | | O | +---+
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | | | X |
    | | | X X X |
    | X | | X X X X |
    | X O | | X X O X X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 87 O: 84 X-O: 0-0
    Cube: 2, O own cube
    X to play 65

    1. Rollout¹ 16/5 eq:+0.274
    Player: 68.29% (G:1.42% B:0.03%)
    Opponent: 31.71% (G:0.81% B:0.02%)
    Confidence: ±0.004 (+0.269..+0.278) - [100.0%]

    2. Rollout¹ 16/10 6/1 eq:+0.226 (-0.048)
    Player: 65.92% (G:1.85% B:0.04%)
    Opponent: 34.08% (G:1.10% B:0.01%)
    Confidence: ±0.004 (+0.221..+0.230) - [0.0%]

    3. Rollout¹ 10/5 10/4* eq:+0.169 (-0.104)
    Player: 60.36% (G:12.57% B:0.44%)
    Opponent: 39.64% (G:9.70% B:0.22%)
    Confidence: ±0.005 (+0.165..+0.174) - [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)