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  • Slot to contain? 6

    From Timothy Chow@21:1/5 to All on Wed Oct 11 08:53:08 2023
    Final problem in this series.

    XGID=-aBBBCB--A----A---bccbBbb-:0:0:1:21:0:0:0:0:10

    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 O |
    | O | | O O O X O O |
    | | | O O |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | | | 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: 112 O: 85 X-O: 0-0
    Cube: 1
    X to play 21

    ---
    Tim Chow

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From ah...Clem@21:1/5 to Timothy Chow on Wed Oct 11 14:02:36 2023
    On 10/11/2023 8:53 AM, Timothy Chow wrote:
    Final problem in this series.

    XGID=-aBBBCB--A----A---bccbBbb-:0:0:1:21:0:0:0:0:10

    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  O |  |                O |   | O  O  O  X  O  O |  |                  |   | O  O             |  |                  |   |                  |
     |                  |   |                  |
     |                  |BAR|                  |
     |                  |   |                  |
     |                  |   |                  |
     |                  |   |    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: 112  O: 85 X-O: 0-0
    Cube: 1
    X to play 21

    I missed problems 3, 4, and 5. My usenet connection seems to be on the blink...

    The "proposition" move looks like 14/13 9/7. Slot the back of the prime
    and bring a builder in range. 17 rolls cover but O only has 11 to hit.
    It looks viable, but X is not gin if he makes the bar point (small rolls
    force him to crunch), X might want to leap with a 65, and there's decent outfield coverage after just shuffling with something like 14/13 5/3.

    So, I'll shuffle here instead of the bold play. Not sure.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Timothy Chow@21:1/5 to ah...Clem on Thu Oct 12 08:38:03 2023
    On 10/11/2023 2:02 PM, ah...Clem wrote:
    I missed problems 3, 4, and 5. My usenet connection seems to be on the blink...

    You should be able to find them here:

    https://bglog.org/rgbnews.html

    ---
    Tim Chow

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Timothy Chow@21:1/5 to All on Fri Oct 13 09:42:35 2023
    XGID=-aBBBCB--A----A---bccbBbb-:0:0:1:21:0:0:0:0:10

    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 O |
    | O | | O O O X O O |
    | | | O O |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | | | 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: 112 O: 85 X-O: 0-0
    Cube: 1
    X to play 21

    This is another subtle one, especially if you compare the position with
    the variant below, in which X's anchor has been shifted by a pip. XG
    favors slotting in the given position, but in the variant, where X's
    back checkers are less boxed in, XG deems the risk not worth taking.
    Notice that, in keeping with the "one-roll proposition" idea, the bold
    slotting play has approximately the same equity in both positions. It's
    the equity of the safe play(s) that change significantly.

    1. Rollout¹ 14/13 9/7 eq:+0.376
    Player: 61.55% (G:6.30% B:0.14%)
    Opponent: 38.45% (G:14.66% B:0.31%)
    Confidence: ±0.004 (+0.372..+0.380) - [100.0%]

    2. Rollout¹ 14/13 5/3 eq:+0.332 (-0.044)
    Player: 60.08% (G:5.59% B:0.15%)
    Opponent: 39.92% (G:9.16% B:0.17%)
    Confidence: ±0.008 (+0.324..+0.340) - [0.0%]

    3. Rollout¹ 9/6 eq:+0.298 (-0.078)
    Player: 60.04% (G:5.44% B:0.14%)
    Opponent: 39.96% (G:7.40% B:0.10%)
    Confidence: ±0.009 (+0.289..+0.306) - [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

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

    XGID=-aBBBCB--A----A---bccBbbb-:0:0:1:21:0:0:0:0:10

    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 O O O |
    | O | | O O X O O O |
    | | | O O |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | | | 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: 110 O: 83 X-O: 0-0
    Cube: 1
    X to play 21

    1. Rollout¹ 14/13 5/3 eq:+0.448
    Player: 63.26% (G:4.58% B:0.13%)
    Opponent: 36.74% (G:8.48% B:0.12%)
    Confidence: ±0.008 (+0.439..+0.456) - [100.0%]

    2. Rollout¹ 9/6 eq:+0.386 (-0.062)
    Player: 62.89% (G:4.84% B:0.12%)
    Opponent: 37.11% (G:6.89% B:0.08%)
    Confidence: ±0.010 (+0.376..+0.396) - [0.0%]

    3. Rollout¹ 9/8 5/3 eq:+0.385 (-0.063)
    Player: 61.42% (G:4.62% B:0.11%)
    Opponent: 38.58% (G:8.91% B:0.14%)
    Confidence: ±0.009 (+0.375..+0.394) - [0.0%]

    4. Rollout¹ 5/2 eq:+0.379 (-0.069)
    Player: 60.97% (G:4.54% B:0.10%)
    Opponent: 39.03% (G:8.60% B:0.11%)
    Confidence: ±0.009 (+0.370..+0.388) - [0.0%]

    5. Rollout¹ 14/13 9/7 eq:+0.360 (-0.088)
    Player: 62.50% (G:5.59% B:0.13%)
    Opponent: 37.50% (G:15.38% B:0.26%)
    Confidence: ±0.003 (+0.357..+0.363) - [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

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)