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  • 4pt vs 7pt 1

    From Timothy Chow@21:1/5 to All on Mon Jun 12 08:49:10 2023
    The position below kicks off a series of "4pt vs 7pt" problems.
    These are positions that I had trouble with at one point in time,
    so they are not necessarily the most useful positions for other
    people to study, but it's what I've got.

    XGID=-a---BEAAa--cD---cbe----B-:0:0:1:11:0:0:0:0:10

    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 |
    | X O | | O |
    | X | | O |
    | | | O |
    | |BAR| |
    | | | X |
    | | | X |
    | O | | X |
    | O | | X X |
    | O O X X | | X X O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 155 O: 147 X-O: 0-0
    Cube: 1
    X to play 11

    ---
    Tim Chow

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  • From ah....Clem@21:1/5 to Timothy Chow on Mon Jun 12 12:01:03 2023
    On 6/12/2023 8:49 AM, Timothy Chow wrote:
    The position below kicks off a series of "4pt vs 7pt" problems.
    These are positions that I had trouble with at one point in time,
    so they are not necessarily the most useful positions for other
    people to study, but it's what I've got.

    XGID=-a---BEAAa--cD---cbe----B-:0:0:1:11:0:0:0:0:10

    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 |
     | X           O    |   | O                |
     | X                |   | O                |
     |                  |   | O                |
     |                  |BAR|                  |
     |                  |   | X                |
     |                  |   | X                |
     | O                |   | X                |
     | O                |   | X  X             |
     | O        O  X  X |   | X  X           O |
     +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count  X: 155  O: 147 X-O: 0-0
    Cube: 1
    X to play 11

    Using all four ones to make the four point leaves the blots on the 7 and
    8 points, so making the bar point seems to be better. Then I have three
    more aces to play so I'll unstack the six point and step up to the 22 point.

    24/22 8/7 6/5.

    --
    Ah....Clem
    The future is fun, the future is fair.

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  • From Timothy Chow@21:1/5 to All on Wed Jun 14 08:29:52 2023
    XGID=-a---BEAAa--cD---cbe----B-:0:0:1:11:0:0:0:0:10

    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 |
    | X O | | O |
    | X | | O |
    | | | O |
    | |BAR| |
    | | | X |
    | | | X |
    | O | | X |
    | O | | X X |
    | O O X X | | X X O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 155 O: 147 X-O: 0-0
    Cube: 1
    X to play 11

    After you've made your 5pt, making your 4pt with snake eyes is usually
    better than making your bar point plus some other random aces. This is especially true when you might be hitting some blots soon, as here.

    This position also illustrates something that I have been slow to learn,
    which is that covering a blot on the bar point is not always better than leaving the bar point slotted and making the 4pt.

    1. Rollout¹ 6/4(2) eq:+0.002
    Player: 49.18% (G:16.62% B:0.55%)
    Opponent: 50.82% (G:13.73% B:0.90%)
    Confidence: ±0.015 (-0.013..+0.017) - [100.0%]

    2. Rollout¹ 24/22 8/7 6/5 eq:-0.061 (-0.063)
    Player: 47.62% (G:14.04% B:0.45%)
    Opponent: 52.38% (G:12.84% B:0.52%)
    Confidence: ±0.013 (-0.074..-0.049) - [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

    ---
    Tim Chow

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