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  • Can't move the back checkers

    From Timothy Chow@21:1/5 to All on Mon Aug 29 07:38:25 2022
    XGID=--aB-BDB--A-dB--ab-c-bb-B-:0:0:1:32:0:0:0:0:10

    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 |
    | X O | | O O O X |
    | | | O |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | O | | X |
    | O | | X |
    | O 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: 138 O: 132 X-O: 0-0
    Cube: 1
    X to play 32

    ---
    Tim Chow

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From ah...Clem@21:1/5 to Timothy Chow on Mon Aug 29 09:50:16 2022
    On 8/29/2022 7:38 AM, Timothy Chow wrote:
    XGID=--aB-BDB--A-dB--ab-c-bb-B-:0:0:1:32:0:0:0:0:10

    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 |
     | X           O    |   | O     O  O     X |  |                  |   | O                |
     |                  |   |                  |
     |                  |   |                  |
     |                  |BAR|                  |
     |                  |   |                  |
     | O                |   | X                |  | O                |   | X                |  | O              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: 138  O: 132 X-O: 0-0
    Cube: 1
    X to play 32


    Keeping the midpoint when there are still runners to escape seems
    thematic. The ten point is worth something, but the simple 10/5 in a
    roughly even race seems like the right idea.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From badgolferman@21:1/5 to Timothy Chow on Mon Aug 29 15:07:39 2022
    Timothy Chow wrote:

    XGID=--aB-BDB--A-dB--ab-c-bb-B-:0:0:1:32:0:0:0:0:10

    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 |
    | X O | | O O O X |
    | | | O |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | O | | X |
    | O | | X |
    | O 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: 138 O: 132 X-O: 0-0
    Cube: 1
    X to play 32

    ---
    Tim Chow


    I can't bring myself to hit so 10/5 seems constructive, especially for
    the next turn.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Timothy Chow@21:1/5 to All on Wed Aug 31 09:13:59 2022
    XGID=--aB-BDB--A-dB--ab-c-bb-B-:0:0:1:32:0:0:0:0:10

    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 |
    | X O | | O O O X |
    | | | O |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | O | | X |
    | O | | X |
    | O 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: 138 O: 132 X-O: 0-0
    Cube: 1
    X to play 32

    XG makes the 4pt here despite leaving a direct shot. Magriel's
    criteria can help here; after 7/4 6/4, X is anchored with the
    stronger board and has more checkers back. Since X is an underdog,
    taking a risk with potentially large upside is justifiable.

    1. Rollout¹ 7/4 6/4 eq:-0.192
    Player: 43.45% (G:18.19% B:0.49%)
    Opponent: 56.55% (G:17.00% B:1.55%)
    Confidence: ±0.012 (-0.204..-0.180) - [100.0%]

    2. Rollout¹ 10/5 eq:-0.258 (-0.066)
    Player: 42.12% (G:15.52% B:0.39%)
    Opponent: 57.88% (G:15.95% B:1.16%)
    Confidence: ±0.014 (-0.272..-0.244) - [0.0%]

    3. Rollout¹ 13/11 13/10 eq:-0.282 (-0.090)
    Player: 41.31% (G:15.55% B:0.42%)
    Opponent: 58.69% (G:16.04% B:1.13%)
    Confidence: ±0.017 (-0.300..-0.265) - [0.0%]

    4. Rollout¹ 7/2* eq:-0.328 (-0.137)
    Player: 41.38% (G:17.36% B:0.46%)
    Opponent: 58.62% (G:20.66% B:2.51%)
    Confidence: ±0.013 (-0.342..-0.315) - [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 Sun Feb 26 08:41:13 2023
    XGID=aAB--CC-A---cB---c-ecA--B-:0:0:1:44:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X O | | O O X X |
    | X O | | O O X |
    | O | | O O |
    | | | O |
    | | | O |
    | |BAR| |
    | | O | |
    | | | |
    | O | | X X |
    | O | | X X X |
    | O X | | X X X X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 141 O: 133 X-O: 0-0
    Cube: 1
    X to play 44

    ---
    Tim Chow

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Robert Zimmerman@21:1/5 to Timothy Chow on Mon Feb 27 06:27:48 2023
    On Sunday, February 26, 2023 at 8:41:14 AM UTC-5, Timothy Chow wrote:
    XGID=aAB--CC-A---cB---c-ecA--B-:0:0:1:44:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X O | | O O X X |
    | X O | | O O X |
    | O | | O O |
    | | | O |
    | | | O |
    | |BAR| |
    | | O | |
    | | | |
    | O | | X X |
    | O | | X X X |
    | O X | | X X X X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 141 O: 133 X-O: 0-0
    Cube: 1
    X to play 44

    ---
    Tim Chow

    5/1 is for sure.
    Next for me is deciding whether to slot the four point. Slotting is a quicker route to making a point and it looks urgent to try to buy time for the back checkers. It's probably favorable to make the four point rather than the three if you can have your
    way and make it more disruptive to O. Would being hit after slotting change things dramatically? Maybe not. It might improve timing and continuity. 16 pips is going to create a lot of space between the three back checkers and the rest. I think I'd slot
    the four.
    Whether to play 13/9 (2) or 13/5: I would favor 13/5 and keep a checker on the 13 point for connectivity with the back checkers and to have some outfield coverage.

    Bob

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Timothy Chow@21:1/5 to All on Tue Feb 28 09:25:22 2023
    XGID=aAB--CC-A---cB---c-ecA--B-:0:0:1:44:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X O | | O O X X |
    | X O | | O O X |
    | O | | O O |
    | | | O |
    | | | O |
    | |BAR| |
    | | O | |
    | | | |
    | O | | X X |
    | O | | X X X |
    | O X | | X X X X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 141 O: 133 X-O: 0-0
    Cube: 1
    X to play 44

    The key question here is whether to slot the 4pt. In general, one
    is willing to take more risks the worse one's position is, on the
    "what have I got to lose?" principle. Here, XG says that slotting
    the 4pt is worth the risk. With a stronger position on the other
    side of the board (see variant), the decision is much closer.

    1. Rollout¹ 13/9(2) 8/4 5/1 eq:+0.105
    Player: 49.74% (G:23.39% B:0.17%)
    Opponent: 50.26% (G:15.19% B:1.27%)
    Confidence: ±0.014 (+0.091..+0.119) - [100.0%]

    2. Rollout¹ 13/9 13/1 eq:+0.027 (-0.078)
    Player: 48.31% (G:21.98% B:0.15%)
    Opponent: 51.69% (G:14.40% B:1.12%)
    Confidence: ±0.009 (+0.018..+0.036) - [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=aAB--CC-A---cB---c-ecC----:0:0:1:44:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X O | | O O X |
    | X O | | O O X |
    | O | | O O X |
    | | | O |
    | | | O |
    | |BAR| |
    | | O | |
    | | | |
    | O | | X X |
    | O | | X X X |
    | O X | | X X X X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 135 O: 133 X-O: 0-0
    Cube: 1
    X to play 44

    1. Rollout¹ 13/9(2) 8/4 5/1 eq:+0.326
    Player: 54.44% (G:22.09% B:0.12%)
    Opponent: 45.56% (G:8.22% B:0.33%)
    Confidence: ±0.006 (+0.320..+0.333) - [99.3%]

    2. Rollout¹ 13/9 13/1 eq:+0.313 (-0.014)
    Player: 54.95% (G:20.99% B:0.10%)
    Opponent: 45.05% (G:7.41% B:0.30%)
    Confidence: ±0.009 (+0.304..+0.321) - [0.7%]

    ¹ 2592 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)