• Another midgame action cube

    From Timothy Chow@21:1/5 to All on Sun Apr 16 18:11:59 2023
    XGID=-bBB--BBAAb--Ba--bccBb--A-:0:0:1:00:0:0:0:0:10

    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 X O X |
    | X O O | | O X O |
    | O | | O |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | | | |
    | O X | | X X X O |
    | O X X X | | X X X O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 143 O: 152 X-O: 0-0
    Cube: 1
    X on roll, cube action

    ---
    Tim Chow

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From pepstein5@gmail.com@21:1/5 to Timothy Chow on Tue Apr 18 04:35:44 2023
    On Sunday, April 16, 2023 at 11:12:02 PM UTC+1, Timothy Chow wrote:
    XGID=-bBB--BBAAb--Ba--bccBb--A-:0:0:1:00:0:0:0:0:10

    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 X O X |
    | X O O | | O X O |
    | O | | O |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | | | |
    | O X | | X X X O |
    | O X X X | | X X X O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 143 O: 152 X-O: 0-0
    Cube: 1
    X on roll, cube action

    ---
    Tim Chow

    The opponent seems to have a lot of play, and the pip count is close with our board not that
    strong. I'm more confident in the take decision than in the double decision.
    A hit followed by a dance is likely to be a market loser, as is making another inner board point.
    Also, the cube is centred.
    Double/Take is my verdict but with no confidence. I'm not even sure my chances of being right
    are greater than 50%.

    Paul

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  • From Timothy Chow@21:1/5 to All on Tue Apr 18 09:48:38 2023
    XGID=-bBB--BBAAb--Ba--bccBb--A-:0:0:1:00:0:0:0:0:10

    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 X O X |
    | X O O | | O X O |
    | O | | O |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | | | |
    | O X | | X X X O |
    | O X X X | | X X X O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 143 O: 152 X-O: 0-0
    Cube: 1
    X on roll, cube action

    It's instructive to compare this position with the previous position
    I posted. There is a superficial similarity: X has the golden anchor,
    which is shooting at a blot on O's 11pt, and O has a 1pt anchor. X has
    a three-point board and O has a two-point board. But clearly, O is
    doing better here; it's X's distribution that is awkward, while O's
    position is (apart from the features already mentioned) pretty sound.

    Still, I'm surprised to see that XG says that doubling is a massive
    blunder here. Even if we upgrade X's 2pt to his 5pt (see variant),
    XG claims it's barely a double.

    Analyzed in Rollout
    No double
    Player Winning Chances: 56.38% (G:20.57% B:1.46%)
    Opponent Winning Chances: 43.62% (G:10.95% B:0.57%)
    Double/Take
    Player Winning Chances: 56.54% (G:20.34% B:1.55%)
    Opponent Winning Chances: 43.46% (G:10.90% B:0.54%)

    Cubeful Equities:
    No double: +0.335
    Double/Take: +0.139 (-0.196)
    Double/Pass: +1.000 (+0.665)

    Best Cube action: No double / Take
    Percentage of wrong pass needed to make the double decision right: 22.7%

    Rollout:
    1296 Games rolled with Variance Reduction.
    Dice Seed: 271828
    Moves: 3-ply, cube decisions: XG Roller
    Confidence No Double: ± 0.016 (+0.319..+0.351)
    Confidence Double: ± 0.022 (+0.117..+0.161)

    eXtreme Gammon Version: 2.19.211.pre-release

    -------
    Variant
    -------

    XGID=-b-B-BBBAAb--Ba--bccBb--A-:0:0:1:00:0:0:0:0:10

    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 X O X |
    | X O O | | O X O |
    | O | | O |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | | | |
    | O X | | X X X O |
    | O X X X | | X X X O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 149 O: 152 X-O: 0-0
    Cube: 1
    X on roll, cube action

    Analyzed in Rollout
    No double
    Player Winning Chances: 66.42% (G:23.95% B:1.54%)
    Opponent Winning Chances: 33.58% (G:7.74% B:0.36%)
    Double/Take
    Player Winning Chances: 66.46% (G:24.88% B:1.61%)
    Opponent Winning Chances: 33.54% (G:7.92% B:0.38%)

    Cubeful Equities:
    No double: +0.751 (-0.015)
    Double/Take: +0.766
    Double/Pass: +1.000 (+0.234)

    Best Cube action: Double / Take

    Rollout:
    1296 Games rolled with Variance Reduction.
    Dice Seed: 271828
    Moves: 3-ply, cube decisions: XG Roller
    Confidence No Double: ± 0.014 (+0.737..+0.765)
    Confidence Double: ± 0.020 (+0.747..+0.786)

    eXtreme Gammon Version: 2.19.211.pre-release

    ---
    Tim Chow

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  • From Timothy Chow@21:1/5 to All on Tue Apr 18 09:51:40 2023
    Incidentally, I want to mention that this position and the
    previous position happened to arise in two separate matches
    that I played against XG on the same day. I misjudged both
    positions OTB.

    ---
    Tim Chow

    --- SoupGate-Win32 v1.05
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