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  • Rolling a prime with 44

    From Timothy Chow@tchow12000@yahoo.com to rec.games.backgammon on Mon Jan 22 09:38:50 2024
    From Newsgroup: rec.games.backgammon

    XGID=-aB--CCBBB-A--------bcdbc-:1:-1:1:44:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | | | O O O O O | +---+
    | | | O O O O O | | 2 |
    | | | O O O | +---+
    | | | O |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | | | X X |
    | X X X | | X X X |
    | X X X X | | X X X O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 96 O: 65 X-O: 0-0
    Cube: 2, O own cube
    X to play 44

    ---
    Tim Chow
    --- Synchronet 3.21b-Linux NewsLink 1.2
  • From ah...Clem@ah_clem@ymail.com to rec.games.backgammon on Tue Jan 23 12:29:16 2024
    From Newsgroup: rec.games.backgammon

    On 1/22/2024 9:38 AM, Timothy Chow wrote:
    XGID=-aB--CCBBB-A--------bcdbc-:1:-1:1:44:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game -a+13-14-15-16-17-18------19-20-21-22-23-24-+ -a|-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a |-a-a |-a-a-a O-a O-a O-a O-a O | +---+ -a|-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a |-a-a |-a-a-a O-a O-a O-a O-a O | | 2 | -a|-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a |-a-a |-a-a-a-a-a-a O-a O-a-a-a-a O | +---+
    -a|-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a |-a-a |-a-a-a-a-a-a-a-a-a O-a-a-a-a-a-a |
    -a|-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a |-a-a |-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a |
    -a|-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a |BAR|-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a |
    -a|-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a |-a-a |-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a |
    -a|-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a |-a-a |-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a |
    -a|-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a |-a-a | X-a X-a-a-a-a-a-a-a-a-a-a-a-a | -a|-a-a-a-a-a-a-a-a-a X-a X-a X |-a-a | X-a X-a-a-a-a-a-a-a X-a-a-a | -a|-a-a-a X-a-a-a-a X-a X-a X |-a-a | X-a X-a-a-a-a-a-a-a X-a O | -a+12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count-a X: 96-a O: 65 X-O: 0-0
    Cube: 2, O own cube
    X to play 44

    Making the four point seems obvious as does keeping the bar point. X
    will be down by 15 pips after this play so don't give O sixes to escape
    and cash.

    I don't think hitting loose is the right idea - it just gives her two
    more rolls to step up to where she can see daylight. Pointing on her
    head also seems to accomplish little - we want her on to stay on the ace
    point.

    So, 8/4(2) 11/7 6/2. Hope she doesn't roll a 52.
    --- Synchronet 3.21b-Linux NewsLink 1.2
  • From Timothy Chow@tchow12000@yahoo.com to rec.games.backgammon on Thu Jan 25 09:20:47 2024
    From Newsgroup: rec.games.backgammon

    XGID=-aB--CCBBB-A--------bcdbc-:1:-1:1:44:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | | | O O O O O | +---+
    | | | O O O O O | | 2 |
    | | | O O O | +---+
    | | | O |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | | | X X |
    | X X X | | X X X |
    | X X X X | | X X X O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 96 O: 65 X-O: 0-0
    Cube: 2, O own cube
    X to play 44

    As ah...clem said, 8/4(2) is pretty obvious. For the remaining two 4's,
    XG recommends slotting with 11/3. This is great when it works, but is
    it too bold? If O had a closed board (see variant below) then XG would
    shy away from the slot, but even with a five-point board, XG judges
    that the risk is worth it. Part of what one has to consider is that X
    is still behind in the pip count, and so will be losing if he plays
    11/7 9/5 8/4(2) and if O then escapes with a roll of 52.

    1. Rollout-| 11/3 8/4(2) eq:+0.586
    Player: 80.35% (G:3.80% B:0.09%)
    Opponent: 19.65% (G:1.60% B:0.01%)
    Confidence: -#0.003 (+0.583..+0.590) - [100.0%]

    2. Rollout-| 11/7 9/5 8/4(2) eq:+0.514 (-0.073)
    Player: 78.11% (G:2.50% B:0.06%)
    Opponent: 21.89% (G:0.55% B:0.00%)
    Confidence: -#0.003 (+0.510..+0.517) - [0.0%]

    3. Rollout-| 11/7 8/4(2) 5/1* eq:+0.510 (-0.076)
    Player: 77.58% (G:3.66% B:0.09%)
    Opponent: 22.42% (G:1.33% B:0.01%)
    Confidence: -#0.004 (+0.506..+0.514) - [0.0%]

    4. Rollout-| 11/7 8/4(2) 6/2 eq:+0.492 (-0.095)
    Player: 77.41% (G:2.43% B:0.05%)
    Opponent: 22.59% (G:0.93% B:0.01%)
    Confidence: -#0.004 (+0.487..+0.496) - [0.0%]

    -| 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=-aB--CCBBB-A-------bbcbbc-:1:-1:1:44:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | | | O O O O O O | +---+
    | | | O O O O O O | | 2 |
    | | | O O | +---+
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | | | X X |
    | X X X | | X X X |
    | X X X X | | X X X O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 96 O: 71 X-O: 0-0
    Cube: 2, O own cube
    X to play 44

    1. Rollout-| 11/7 9/5 8/4(2) eq:+0.514
    Player: 77.53% (G:2.53% B:0.06%)
    Opponent: 22.47% (G:0.80% B:0.01%)
    Confidence: -#0.004 (+0.510..+0.518) - [100.0%]

    2. Rollout-| 11/3 8/4(2) eq:+0.493 (-0.021)
    Player: 75.78% (G:3.74% B:0.10%)
    Opponent: 24.22% (G:2.55% B:0.01%)
    Confidence: -#0.004 (+0.489..+0.497) - [0.0%]

    3. Rollout-| 11/7 8/4(2) 6/2 eq:+0.484 (-0.030)
    Player: 77.02% (G:2.42% B:0.05%)
    Opponent: 22.98% (G:1.17% B:0.02%)
    Confidence: -#0.005 (+0.479..+0.489) - [0.0%]

    -| 1296 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
    --- Synchronet 3.21b-Linux NewsLink 1.2