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  • 5pt problem 3

    From Timothy Chow@21:1/5 to All on Fri Oct 28 09:10:45 2022
    XGID=--bBB-DBCA-ab---abad-Ab---:1:-1:1:41:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | O O O | | O X O | +---+
    | O | | O O | | 2 |
    | | | O | +---+
    | | | O |
    | | | |
    | |BAR| |
    | | | |
    | | | X |
    | X | | X |
    | O X X | | X X X O |
    | O O X X X | | X X X O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 106 O: 148 X-O: 0-0
    Cube: 2, O own cube
    X to play 41

    ---
    Tim Chow

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From ah....Clem@21:1/5 to Timothy Chow on Fri Oct 28 21:18:45 2022
    On 10/28/2022 9:10 AM, Timothy Chow wrote:
    XGID=--bBB-DBCA-ab---abad-Ab---:1:-1:1:41:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
     +13-14-15-16-17-18------19-20-21-22-23-24-+
     |          O  O  O |   | O     X  O       | +---+
     |             O    |   | O        O       | | 2 |
     |                  |   | O                | +---+
     |                  |   | O                |
     |                  |   |                  |
     |                  |BAR|                  |
     |                  |   |                  |
     |                  |   | X                |
     |             X    |   | X                |
     | O           X  X |   | X     X  X  O    |
     | O  O     X  X  X |   | X     X  X  O    |
     +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count  X: 106  O: 148 X-O: 0-0
    Cube: 2, O own cube
    X to play 41

    Making the five point builds a full prime. Usually that's the best choice.

    Is hitting better? It appears to win more gammons, although often the
    play that wins more gammons does that because it wins more games.

    O has 13 checkers ready to pounce on the straggler, so perhaps taking
    away half O's roll is the right idea, and there are a few rolls that
    trap the runner and break the prime. But I can't resist making the full
    prime.

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

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  • From [email protected]@21:1/5 to Tim Chow on Sat Oct 29 04:16:55 2022
    On Friday, October 28, 2022 at 2:10:47 PM UTC+1, Tim Chow wrote:
    XGID=--bBB-DBCA-ab---abad-Ab---:1:-1:1:41:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | O O O | | O X O | +---+
    | O | | O O | | 2 |
    | | | O | +---+
    | | | O |
    | | | |
    | |BAR| |
    | | | |
    | | | X |
    | X | | X |
    | O X X | | X X X O |
    | O O X X X | | X X X O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 106 O: 148 X-O: 0-0
    Cube: 2, O own cube
    X to play 41

    I'd definitely hit on the 16 here.
    Making the full prime gives plenty of opportunities for the opponent to attack and trap
    and then win when we have to disintegrate our prime.
    So I think hitting on 16 is also the DMP play.
    Note the duplication in that 5 is an entering number as well as a return-hitting number.

    Paul

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  • From Timothy Chow@21:1/5 to All on Sun Oct 30 08:47:47 2022
    XGID=--bBB-DBCA-ab---abad-Ab---:1:-1:1:41:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | O O O | | O X O | +---+
    | O | | O O | | 2 |
    | | | O | +---+
    | | | O |
    | | | |
    | |BAR| |
    | | | |
    | | | X |
    | X | | X |
    | O X X | | X X X O |
    | O O X X X | | X X X O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 106 O: 148 X-O: 0-0
    Cube: 2, O own cube
    X to play 41

    Making the 5pt *and* completing a six-prime---what's not to like?
    Well, for starters, O has enough counterplay against X's straggler
    that the six-prime is far from the "guaranteed win" that it often is
    (when I say "guaranteed," I mean ~90%, not 100%). Note for example
    that after 9/5 6/5, any 6 that X can't play with his straggler will
    crack his six-prime. X's five-prime already contains much of the
    power of the six-prime here, and hitting certainly wins a lot more
    gammons---X has good chances of picking up yet another blot.

    1. Rollout¹ 21/16* eq:+0.649
    Player: 73.28% (G:30.82% B:1.82%)
    Opponent: 26.72% (G:3.36% B:0.12%)
    Confidence: ±0.008 (+0.641..+0.657) - [100.0%]

    2. Rollout¹ 9/5 6/5 eq:+0.487 (-0.161)
    Player: 71.39% (G:19.59% B:1.00%)
    Opponent: 28.61% (G:3.61% B:0.14%)
    Confidence: ±0.008 (+0.479..+0.496) - [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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