• Prime cube action

    From Timothy Chow@21:1/5 to All on Sat Nov 11 11:25:02 2023
    XGID=--b-B-CBC--AAA--bb-ccBaaa-:0:0:1:00:0:0:0:0:10

    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 O X |
    | | | O O |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | X | | X |
    | X X | | X X O |
    | X X X X | | X X O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 142 O: 119 X-O: 0-0
    Cube: 1
    X on roll, cube action

    ---
    Tim Chow

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From ah....Clem@21:1/5 to Timothy Chow on Sat Nov 11 12:21:46 2023
    On 11/11/2023 11:25 AM, Timothy Chow wrote:
    XGID=--b-B-CBC--AAA--bb-ccBaaa-:0:0:1:00:0:0:0:0:10

    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  O  X          |
     |                  |   | O  O             |
     |                  |   |                  |
     |                  |   |                  |
     |                  |BAR|                  |
     |                  |   |                  |
     |                  |   |                  |
     |             X    |   | X                |
     |             X  X |   | X     X     O    |
     | X  X        X  X |   | X     X     O    |
     +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count  X: 142  O: 119 X-O: 0-0
    Cube: 1
    X on roll, cube action


    X has the better position, O is ahead in the race, and there are no
    direct threats so PRAT would say ND/T.

    But X stands to improve his position while O is on the verge of
    collapsing. So I'll ship it. Some will pass this, so a good practical
    double even if XG says hold.

    D/T.

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

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Stick Rice@21:1/5 to ah....Clem on Sun Nov 12 12:12:51 2023
    On Saturday, November 11, 2023 at 12:21:48 PM UTC-5, ah....Clem wrote:
    On 11/11/2023 11:25 AM, Timothy Chow wrote:
    XGID=--b-B-CBC--AAA--bb-ccBaaa-:0:0:1:00:0:0:0:0:10

    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 O X |
    | | | O O |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | X | | X |
    | X X | | X X O |
    | X X X X | | X X O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 142 O: 119 X-O: 0-0
    Cube: 1
    X on roll, cube action
    X has the better position, O is ahead in the race, and there are no
    direct threats so PRAT would say ND/T.

    But X stands to improve his position while O is on the verge of
    collapsing. So I'll ship it. Some will pass this, so a good practical
    double even if XG says hold.

    D/T.

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

    Doesn't matter if you're up in the race if you can't race.

    Stick

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Timothy Chow@21:1/5 to All on Tue Nov 14 09:39:26 2023
    XGID=--b-B-CBC--AAA--bb-ccBaaa-:0:0:1:00:0:0:0:0:10

    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 O X |
    | | | O O |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | X | | X |
    | X X | | X X O |
    | X X X X | | X X O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 142 O: 119 X-O: 0-0
    Cube: 1
    X on roll, cube action

    X has a big advantage in this priming battle, and O's blots in
    her home board don't help---they mean that even if O hits a fly
    shot, it won't help her much. According to the rollout, this is
    a big pass.

    Ah...clem mentioned PRAT, and so might be interested in what Marc
    Olsen has to say in his book with Mochy, "Backgammon Masterclass."
    In a nutshell, his modification of PRAT says that you always need
    threats (read: market losers) to double (unless you've already lost
    your market), and he splits Position into Prime and Blitz. So now
    you're looking for 2 out of the 3 areas Prime, Blitz, and Race. One
    final nuance is that a big enough priming threat can be enough all
    by itself. That final nuance applies here. The other thing to be
    aware of, as Stick briefly alluded to, is that in a priming battle,
    it's often an advantage to be *behind* in the race because it often
    means you have a timing advantage.

    Analyzed in Rollout
    No double
    Player Winning Chances: 74.76% (G:18.67% B:0.82%)
    Opponent Winning Chances: 25.24% (G:5.52% B:0.17%)
    Double/Take
    Player Winning Chances: 75.41% (G:19.08% B:0.95%)
    Opponent Winning Chances: 24.59% (G:5.81% B:0.22%)

    Cubeful Equities:
    No double: +0.912 (-0.088)
    Double/Take: +1.132 (+0.132)
    Double/Pass: +1.000

    Best Cube action: Double / Pass

    Rollout:
    1296 Games rolled with Variance Reduction.
    Dice Seed: 271828
    Moves: 3-ply, cube decisions: XG Roller
    Confidence No Double: ± 0.010 (+0.902..+0.922)
    Confidence Double: ± 0.014 (+1.118..+1.147)

    eXtreme Gammon Version: 2.19.211.pre-release

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

    XGID=--b-B-CBC--AAA--bb-ccBba--:0:0:1:00:0:0:0:0:10

    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 |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | X | | X |
    | X X | | X X O |
    | X X X X | | X X O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 142 O: 121 X-O: 0-0
    Cube: 1
    X on roll, cube action

    Analyzed in Rollout
    No double
    Player Winning Chances: 72.90% (G:16.81% B:0.58%)
    Opponent Winning Chances: 27.10% (G:5.76% B:0.16%)
    Double/Take
    Player Winning Chances: 73.24% (G:16.85% B:0.63%)
    Opponent Winning Chances: 26.76% (G:5.80% B:0.18%)

    Cubeful Equities:
    No double: +0.840 (-0.137)
    Double/Take: +0.977
    Double/Pass: +1.000 (+0.023)

    Best Cube action: Double / Take

    Rollout:
    1296 Games rolled with Variance Reduction.
    Dice Seed: 271828
    Moves: 3-ply, cube decisions: XG Roller
    Confidence No Double: ± 0.009 (+0.831..+0.849)
    Confidence Double: ± 0.014 (+0.964..+0.991)

    eXtreme Gammon Version: 2.19.211.pre-release

    ---
    Tim Chow

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