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  • Please stop spreading false rumours about double aces in the opening

    From [email protected]@21:1/5 to All on Sat Oct 1 23:57:10 2022
    24/22 with double aces in the opening seems counter-intuitive to me, but,
    I thought, if that's what the theory says, I'm happy to roll with it.
    But I got massively dinged for playing it here.
    Maybe the point is that 24/22 puts me under the gun too much.
    I think 8/7(2) 6/5(2) might generally be the safest from a PR standpoint,
    if you don't want to do too much memorization. When 24/22 is best,
    it might not be best by so much.
    Of course, 8/7(2) should be played with caution if it exposes a direct shot.

    Paul

    XGID=-b----E-C---cE-aac-e----B-:0:0:1:11:2:0:3:0:10
    X:Daniel O:eXtremeGammon

    Score is X:2 O:0. Unlimited Game, Jacoby Beaver
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X O O O | | O X |
    | X O | | O X |
    | X O | | O |
    | X | | O |
    | X | | O |
    | |BAR| |
    | | | X |
    | | | X |
    | O X | | X |
    | O X | | X O |
    | O X | | X O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 167 O: 160 X-O: 2-0
    Cube: 1
    X to play 11

    1. Book¹ 8/7(2) 6/5(2) eq:+0.219
    Player: 55.70% (G:16.42% B:0.92%)
    Opponent: 44.30% (G:13.89% B:0.79%)

    2. XG Roller+ 24/22 6/5(2) eq:+0.128 (-0.091)
    Player: 53.90% (G:14.23% B:0.73%)
    Opponent: 46.10% (G:13.92% B:0.50%)

    3. Book¹ 8/5 6/5 eq:+0.055 (-0.164)
    Player: 51.51% (G:15.02% B:0.75%)
    Opponent: 48.49% (G:15.27% B:0.77%)

    4. 3-ply 24/23 6/5(3) eq:+0.100 (-0.118)
    Player: 53.30% (G:14.56% B:0.78%)
    Opponent: 46.70% (G:14.35% B:0.55%)

    5. 3-ply 24/23(2) 6/5(2) eq:+0.084 (-0.135)
    Player: 52.43% (G:14.37% B:0.73%)
    Opponent: 47.57% (G:13.25% B:0.54%)


    ¹Generated by GameSite 2000, Ltd on 26/02/2011 using eXtreme Gammon 2.00
    Analyzed in XG Roller++


    eXtreme Gammon Version: 2.10

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  • From Axel Reichert@21:1/5 to [email protected] on Sun Oct 2 10:17:13 2022
    "[email protected]" <[email protected]> writes:

    I think 8/7(2) 6/5(2) might generally be the safest from a PR
    standpoint, if you don't want to do too much memorization. When 24/22
    is best, it might not be best by so much. Of course, 8/7(2) should be
    played with caution if it exposes a direct shot.

    Now you are getting close. Like you I do not want too much memorization:
    I play 6/4*(2) if possible, 24/22 6/5(2) after a non-6 split, and 8/7(2)
    6/5(2) else. See

    https://bkgm.com/articles/Reichert/first-two-rolls-flowcharts.pdf

    This heuristic is always below 0.01 equity loss. See page 53 of

    https://bkgm.com/articles/Reichert/first-two-rolls.pdf

    Best regards

    Axel

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  • From Timothy Chow@21:1/5 to [email protected] on Sun Oct 2 08:12:27 2022
    On 10/2/2022 2:57 AM, [email protected] wrote:
    24/22 with double aces in the opening seems counter-intuitive to me, but,
    I thought, if that's what the theory says, I'm happy to roll with it.
    But I got massively dinged for playing it here.
    Maybe the point is that 24/22 puts me under the gun too much.
    I think 8/7(2) 6/5(2) might generally be the safest from a PR standpoint,
    if you don't want to do too much memorization. When 24/22 is best,
    it might not be best by so much.
    Of course, 8/7(2) should be played with caution if it exposes a direct shot.

    It absolutely is *NOT* because 24/22 puts you "under the gun."
    Speaking of false rumors, the "under the gun" heuristic is one of
    the least helpful "rules" that Magriel proposed. I think I mentioned
    not long ago that I've found that it mostly applies only when you are
    choosing between two different splits, not when you are deciding whether
    to split at all.

    But otherwise, yes, if you roll 11 on the second roll and you can't
    hit, then 8/7(2) 6/5(2) is the usual play, unless it exposes a direct
    shot. What I mentioned before is that rollouts suggest that 24/22
    6/5(2) is preferred when your opponent has opened with 8/5 6/5. The
    point is that 8/5 6/5 is a stronger priming play than most people
    give it credit for. In your position here, your opponent has no prime
    to worry about, so there's no reason to favor 24/22 over 8/7(2).

    ---
    Tim Chow

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