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  • Time to split? Or not?

    From ah....Clem@21:1/5 to All on Wed Oct 18 11:10:49 2023
    XGID=--ab-CCBBA--AAba-b-cbb--B-:0:0:1:62:0:0:3:0:10

    X:Player 1 O:Player 2
    Score is X:0 O:0. Unlimited Game, Jacoby Beaver
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X O O O | | O O O X |
    | O O | | O O O X |
    | | | O |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | | | X X |
    | X X | | X X O |
    | X X X X | | X X O O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 145 O: 151 X-O: 0-0
    Cube: 1
    X to play 62


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

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Timothy Chow@21:1/5 to ah....Clem on Thu Oct 19 09:14:32 2023
    On 10/18/2023 11:10 AM, ah....Clem wrote:


    XGID=--ab-CCBBA--AAba-b-cbb--B-:0:0:1:62:0:0:3:0:10

    X:Player 1   O:Player 2
    Score is X:0 O:0. Unlimited Game, Jacoby Beaver
     +13-14-15-16-17-18------19-20-21-22-23-24-+
     | X  O  O     O    |   | O  O  O        X |
     |    O        O    |   | O  O  O        X |
     |                  |   | O                |
     |                  |   |                  |
     |                  |   |                  |
     |                  |BAR|                  |
     |                  |   |                  |
     |                  |   |                  |
     |                  |   | X  X             |
     |             X  X |   | X  X     O       |
     | X        X  X  X |   | X  X     O  O    |
     +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count  X: 145  O: 151 X-O: 0-0
    Cube: 1
    X to play 62

    Tough call. When the opponent has made an advanced anchor, or even
    the 3pt anchor as in this position, and we're still on the 24pt, then
    that is usually a strong indication that we need to split. This is
    especially true if we're ahead in the pip count and facing a serious
    priming threat. So that would suggest 24/18, and then I guess 9/7 to
    reduce our blot count.

    On the other hand, the main alternative play I see, 9/4 6/4, makes a
    five-prime and uses our spare on the 6pt efficiently. It also
    equalizes board strength. OTB, I think I would go for the five-prime,
    but it wouldn't shock me to learn that the bot prefers to split.

    ---
    Tim Chow

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Timothy Chow@21:1/5 to All on Thu Oct 19 09:15:44 2023
    On 10/19/2023 9:14 AM, I wrote:
    On the other hand, the main alternative play I see, 9/4 6/4

    Wait, what nonsense is this? 9/4 6/4 is illegal. So my play
    is 24/18 9/7.

    ---
    Tim Chow

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From ah...Clem@21:1/5 to All on Fri Oct 20 14:43:57 2023
    XGID=--ab-CCBBA--AAba-b-cbb--B-:0:0:1:62:0:0:3:0:10

    X:Player 1 O:Player 2
    Score is X:0 O:0. Unlimited Game, Jacoby Beaver
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X O O O | | O O O X |
    | O O | | O O O X |
    | | | O |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | | | X X |
    | X X | | X X O |
    | X X X X | | X X O O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 145 O: 151 X-O: 0-0
    Cube: 1
    X to play 62

    I don't like sitting on the ace point waiting patiently to lose, so I
    split to the 18 and moved the blot on the nine to safety. And that is
    XG's play at three ply.

    The rollout tells a very different story, with that play being nearly a
    blunder at .071 error. And XG hates splitting to the 22.

    David Potter had this to say:

    "This one is very tricky. The top move cleans up all our blots so it
    becomes safer for us to escape in the next few rolls. It's also
    difficult for both sides to make a prime and escape their checkers, so
    blitzing goes up in importance which is why we shouldn't split the back checkers yet."

    In the variant I've moved O's blot on the 15 to the 14 and moved X's
    blot on the 13 to the 12 to tidy up. With fewer shots at the 18 and
    fewer blots to shoot at the split is massively favored according to XGR++.




    1. Rollout¹ 12/6 9/7 eq:-0.195
    Player: 45.61% (G:13.72% B:0.74%)
    Opponent: 54.39% (G:17.54% B:0.99%)
    Confidence: ±0.016 (-0.211..-0.180) - [100.0%]
    Duration: 4 minutes 58 seconds

    2. Rollout¹ 13/7 9/7 eq:-0.236 (-0.041)
    Player: 44.61% (G:13.51% B:0.68%)
    Opponent: 55.39% (G:18.12% B:0.98%)
    Confidence: ±0.016 (-0.252..-0.220) - [0.0%]
    Duration: 4 minutes 34 seconds

    3. Rollout¹ 24/18 9/7 eq:-0.266 (-0.071)
    Player: 46.72% (G:14.52% B:0.92%)
    Opponent: 53.28% (G:23.00% B:1.74%)
    Confidence: ±0.018 (-0.284..-0.248) - [0.0%]
    Duration: 5 minutes 16 seconds

    4. Rollout¹ 24/16 eq:-0.330 (-0.135)
    Player: 45.37% (G:12.69% B:0.75%)
    Opponent: 54.63% (G:28.26% B:3.94%)
    Confidence: ±0.015 (-0.345..-0.315) - [0.0%]
    Duration: 3 minutes 53 seconds

    5. XG Roller++ 24/22 13/7 eq:-0.403 (-0.207)
    Player: 42.02% (G:12.66% B:0.77%)
    Opponent: 57.98% (G:24.19% B:2.11%)


    ¹ 1296 Games rolled with Variance Reduction.
    Moves: 3-ply, cube decisions: XG Roller


    eXtreme Gammon Version: 2.10






    ///////////////////////
    //variant
    //////////////////////

    XGID=--ab-CCBBA--B-c--b-cbb--B-:0:0:1:62:0:0:3:0:10

    X:Player 1 O:Player 2
    Score is X:0 O:0. Unlimited Game, Jacoby Beaver
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | O O | | O O O X |
    | O O | | O O O X |
    | O | | O |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | | | X X |
    | X X X | | X X O |
    | X X X X | | X X O O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 144 O: 152 X-O: 0-0
    Cube: 1
    X to play 62

    1. XG Roller++ 24/18 9/7 eq:+0.115
    Player: 53.70% (G:14.85% B:0.78%)
    Opponent: 46.30% (G:15.02% B:0.62%)

    2. XG Roller++ 24/16 eq:-0.095 (-0.210)
    Player: 49.75% (G:13.64% B:0.70%)
    Opponent: 50.25% (G:19.45% B:1.10%)

    3. XG Roller++ 12/6 9/7 eq:-0.154 (-0.269)
    Player: 46.40% (G:13.59% B:0.61%)
    Opponent: 53.60% (G:16.36% B:0.84%)

    4. XG Roller++ 24/22 24/18 eq:-0.371 (-0.486)
    Player: 44.01% (G:12.09% B:0.64%)
    Opponent: 55.99% (G:24.88% B:1.48%)




    eXtreme Gammon Version: 2.10

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Timothy Chow@21:1/5 to All on Sat Oct 21 18:21:22 2023
    Interesting position. Here's another variant.


    XGID=--ab-BCCBA--AAba-b-cbb--B-:0:0:1:62:0:0:3:0:10

    Score is X:0 O:0. Unlimited Game, Jacoby Beaver
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X O O O | | O O O X |
    | O O | | O O O X |
    | | | O |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | X | | X |
    | X X | | X X O |
    | X X X X | | X X O O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 147 O: 151 X-O: 0-0
    Cube: 1
    X to play 62

    1. Rollout¹ 24/18 9/7 eq:-0.250
    Player: 46.38% (G:13.63% B:0.81%)
    Opponent: 53.62% (G:22.74% B:1.68%)
    Confidence: ±0.017 (-0.267..-0.233) - [59.8%]

    2. Rollout¹ 12/6 9/7 eq:-0.253 (-0.003)
    Player: 44.43% (G:13.15% B:0.78%)
    Opponent: 55.57% (G:18.24% B:0.96%)
    Confidence: ±0.016 (-0.268..-0.237) - [40.2%]

    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)