• A more sophisticated Axelisation gives the right answer -- a must-read

    From pepstein5@gmail.com@21:1/5 to All on Sun May 29 08:15:23 2022
    If XG had all six checkers on the ace, it's a clear (clear in the
    sense of everyone knows it) D/P.
    However, XG's position is clearly worse than that, so it may not
    be obvious that the position below is still a pass.
    I think that for variantizations of 3 rolls vs 3 rolls to be a take,
    the on-roll player needs to have an anti-joker. Here, XG doesn't
    have any -- a 21 would not be as bad as a can't-import-module error
    when you're trying to code in python.

    So I was pretty confident about the pass, but not quite 100% confident.
    But how does this position Axelise?
    Here, we have to realise that mathematically, the position is exactly equivalent to what it would be if I had 6 checkers on my ace instead of 5. There are two equivalent representations of exactly the same position.
    So it would be absurd to say that one of these postions is a pass and the
    other is a take. Let's Axelise both and take the mean.
    For the current position, the raw pip counts are 10 and 5.
    XG's stack penalty is 2 and mine is 6.
    14 - 11 = 3.
    But there's another equally valid representation.
    How would we Axelise if I had six checkers on my ace point?
    Then my count would be 6, and my penalty would be 8 leading to
    a score of 14-14 = 0.
    Now take the average: (0 + 3)/2 = 1.5 which is the correct pass zone.

    Paul




    XGID=-E--------------------abc-:1:-1:-1:00:0:5:3:0:10
    X:eXtremeGammon O:Daniel

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

    Analyzed in 4-ply
    Player Winning Chances: 76.58% (G:0.00% B:0.00%)
    Opponent Winning Chances: 23.42% (G:0.00% B:0.00%)

    Cubeless Equities: No Double=+0.532, Double=+1.063

    Cubeful Equities:
    No redouble: +0.745 (-0.255)
    Redouble/Take: +1.026 (+0.026)
    Redouble/Pass: +1.000

    Best Cube action: Redouble / Pass

    eXtreme Gammon Version: 2.10

    --- SoupGate-Win32 v1.05
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