• Pottle or not? 2

    From Timothy Chow@21:1/5 to All on Fri Mar 4 08:36:44 2022
    XGID=----a-EbC--BcDaa---c-bb--A:0:0:1:62:0:0:0:0:10

    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 |
    | X | | O O O |
    | X | | O |
    | X | | |
    | | X | |
    | |BAR| |
    | | | X |
    | | | X |
    | O X | | X |
    | O X X O | | X |
    | O X X O | | X O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 153 O: 149 X-O: 0-0
    Cube: 1
    X to play 62

    ---
    Tim Chow

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Timothy Chow@21:1/5 to All on Sun Mar 6 10:46:35 2022
    XGID=----a-EbC--BcDaa---c-bb--A:0:0:1:62:0:0:0:0:10

    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 |
    | X | | O O O |
    | X | | O |
    | X | | |
    | | X | |
    | |BAR| |
    | | | X |
    | | | X |
    | O X | | X |
    | O X X O | | X |
    | O X X O | | X O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 153 O: 149 X-O: 0-0
    Cube: 1
    X to play 62

    I have quoted Mochy before as saying that 8/2 is "illegal in Denmark."

    http://www.bgonline.org/forums/webbbs_config.pl?read=139316

    In this position, an intermediate might play 8/2 quickly because
    stepping into a triple shot seems like leading with the chin.
    Paradoxically, a more advanced player might have more trouble with
    this decision. See the variant for comparison.

    1. Rollout¹ Bar/23 8/2 eq:-0.409
    Player: 41.41% (G:9.39% B:0.38%)
    Opponent: 58.59% (G:21.60% B:0.55%)
    Confidence: ±0.014 (-0.423..-0.396) - [100.0%]

    2. Rollout¹ Bar/17 eq:-0.500 (-0.091)
    Player: 40.02% (G:6.52% B:0.30%)
    Opponent: 59.98% (G:20.91% B:0.49%)
    Confidence: ±0.012 (-0.512..-0.488) - [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=----a-EbC--BcD--aa-c-bb--A:0:0:1:61:0:0:0:0:10

    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 |
    | X | | O O O |
    | X | | O |
    | X | | |
    | | X | |
    | |BAR| |
    | | | X |
    | | | X |
    | O X | | X |
    | O X X O | | X |
    | O X X O | | X O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 153 O: 145 X-O: 0-0
    Cube: 1
    X to play 61

    1. Rollout¹ Bar/18 eq:-0.543
    Player: 38.85% (G:5.83% B:0.27%)
    Opponent: 61.15% (G:21.14% B:0.42%)
    Confidence: ±0.006 (-0.549..-0.536) - [99.7%]

    2. Rollout¹ Bar/24 8/2 eq:-0.557 (-0.014)
    Player: 37.71% (G:7.47% B:0.33%)
    Opponent: 62.29% (G:20.95% B:0.58%)
    Confidence: ±0.008 (-0.565..-0.549) - [0.3%]

    ¹ 5184 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 Wed Sep 21 08:34:53 2022
    XGID=---B-BCcB-B-bB-A-e-b--Aab-:0:0:1:61:0:0:0:0:10

    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 X O | | O X O O |
    | X O | | O O |
    | O | | |
    | O | | |
    | O | | |
    | |BAR| |
    | | | |
    | | | |
    | O | | X |
    | O X X O | | X X X |
    | O X X O | | X X X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 133 O: 136 X-O: 0-0
    Cube: 1
    X to play 61

    ---
    Tim Chow

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From ah...Clem@21:1/5 to Timothy Chow on Wed Sep 21 10:56:13 2022
    On 9/21/2022 8:34 AM, Timothy Chow wrote:
    XGID=---B-BCcB-B-bB-A-e-b--Aab-:0:0:1:61:0:0:0:0:10

    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     X     O    |   | O        X  O  O |
     | X           O    |   | O              O |  |             O    |   |                  |
     |             O    |   |                  |
     |             O    |   |                  |
     |                  |BAR|                  |
     |                  |   |                  |
     |                  |   |                  |
     |                O |   | X                |  | O     X     X  O |   | X  X     X       |
     | O     X     X  O |   | X  X     X       |  +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count  X: 133  O: 136 X-O: 0-0
    Cube: 1
    X to play 61

    X is ahead in the race. Does 15/8 afford more options to just bring the checkers home? Making the fifteen point is "obvious", but may be harder
    to clear than simply waiting to run the straggler.

    As with the last position, there's nothing "very constructive" to do
    elsewhere, so I'll make the fifteen point.

    --- SoupGate-Win32 v1.05
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  • From Timothy Chow@21:1/5 to All on Fri Sep 23 08:30:58 2022
    XGID=---B-BCcB-B-bB-A-e-b--Aab-:0:0:1:61:0:0:0:0:10

    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 X O | | O X O O |
    | X O | | O O |
    | O | | |
    | O | | |
    | O | | |
    | |BAR| |
    | | | |
    | | | |
    | O | | X |
    | O X X O | | X X X |
    | O X X O | | X X X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 133 O: 136 X-O: 0-0
    Cube: 1
    X to play 61

    Generally speaking, the reason one Pottles is because one's last
    checker is in danger of being attacked or primed. But in this
    position, O's structure is weak enough that X's last checker
    serves an offensive function: If X stays back, O has quite a
    few blotting rolls that will give X a direct shot. If X Pottles
    with 22/15, then he lets O off the hook.

    1. Rollout¹ 15/8 eq:+0.435
    Player: 61.36% (G:14.07% B:0.37%)
    Opponent: 38.64% (G:5.80% B:0.11%)
    Confidence: ±0.012 (+0.423..+0.448) - [100.0%]

    2. Rollout¹ 15/9 6/5 eq:+0.384 (-0.051)
    Player: 59.67% (G:16.03% B:0.52%)
    Opponent: 40.33% (G:7.57% B:0.15%)
    Confidence: ±0.013 (+0.371..+0.398) - [0.0%]

    3. Rollout¹ 22/21 15/9 eq:+0.376 (-0.059)
    Player: 59.85% (G:14.56% B:0.50%)
    Opponent: 40.15% (G:8.08% B:0.15%)
    Confidence: ±0.012 (+0.364..+0.388) - [0.0%]

    4. Rollout¹ 15/9 10/9 eq:+0.350 (-0.085)
    Player: 59.26% (G:15.62% B:0.49%)
    Opponent: 40.74% (G:7.78% B:0.14%)
    Confidence: ±0.012 (+0.338..+0.363) - [0.0%]

    5. Rollout¹ 22/15 eq:+0.318 (-0.117)
    Player: 59.85% (G:4.23% B:0.17%)
    Opponent: 40.15% (G:2.77% B:0.05%)
    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: 2.19.207.pre-release

    ---
    Tim Chow

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Stick Rice@21:1/5 to Tim Chow on Fri Sep 23 09:47:54 2022
    On Friday, September 23, 2022 at 8:30:59 AM UTC-4, Tim Chow wrote:
    XGID=---B-BCcB-B-bB-A-e-b--Aab-:0:0:1:61:0:0:0:0:10

    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 X O | | O X O O |
    | X O | | O O |
    | O | | |
    | O | | |
    | O | | |
    | |BAR| |
    | | | |
    | | | |
    | O | | X |
    | O X X O | | X X X |
    | O X X O | | X X X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 133 O: 136 X-O: 0-0
    Cube: 1
    X to play 61
    Generally speaking, the reason one Pottles is because one's last
    checker is in danger of being attacked or primed. But in this
    position, O's structure is weak enough that X's last checker
    serves an offensive function: If X stays back, O has quite a
    few blotting rolls that will give X a direct shot. If X Pottles
    with 22/15, then he lets O off the hook.

    1. Rollout¹ 15/8 eq:+0.435
    Player: 61.36% (G:14.07% B:0.37%)
    Opponent: 38.64% (G:5.80% B:0.11%)
    Confidence: ±0.012 (+0.423..+0.448) - [100.0%]

    2. Rollout¹ 15/9 6/5 eq:+0.384 (-0.051)
    Player: 59.67% (G:16.03% B:0.52%)
    Opponent: 40.33% (G:7.57% B:0.15%)
    Confidence: ±0.013 (+0.371..+0.398) - [0.0%]

    3. Rollout¹ 22/21 15/9 eq:+0.376 (-0.059)
    Player: 59.85% (G:14.56% B:0.50%)
    Opponent: 40.15% (G:8.08% B:0.15%)
    Confidence: ±0.012 (+0.364..+0.388) - [0.0%]

    4. Rollout¹ 15/9 10/9 eq:+0.350 (-0.085)
    Player: 59.26% (G:15.62% B:0.49%)
    Opponent: 40.74% (G:7.78% B:0.14%)
    Confidence: ±0.012 (+0.338..+0.363) - [0.0%]

    5. Rollout¹ 22/15 eq:+0.318 (-0.117)
    Player: 59.85% (G:4.23% B:0.17%)
    Opponent: 40.15% (G:2.77% B:0.05%)
    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: 2.19.207.pre-release

    ---
    Tim Chow

    I only quickly went through all the rolls in my head but I don't see that O has any rolls that *force him to leave a direct shot.

    Stick

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