1. Forum
  2. Usenet
  3. REC.GAMES.BACKGAMMON

  • 2-4 backgamee play

    From Timothy Chow@21:1/5 to All on Wed Jun 28 08:27:58 2023
    XGID=aBbcBBCCB---A--a---cbab---:1:-1:1:42:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | O | | O O O O | +---+
    | | | O O O | | 2 |
    | | | O | +---+
    | | | |
    | | | |
    | |BAR| |
    | | O | |
    | | | |
    | X | | X O |
    | X X | | X X X O O X |
    | X X X | | X X X O O X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 87 O: 185 X-O: 0-0
    Cube: 2, O own cube
    X to play 42

    ---
    Tim Chow

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Stick Rice@21:1/5 to Timothy Chow on Wed Jun 28 08:38:32 2023
    On Wednesday, June 28, 2023 at 8:28:01 AM UTC-4, Timothy Chow wrote:
    XGID=aBbcBBCCB---A--a---cbab---:1:-1:1:42:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | O | | O O O O | +---+
    | | | O O O | | 2 |
    | | | O | +---+
    | | | |
    | | | |
    | |BAR| |
    | | O | |
    | | | |
    | X | | X O |
    | X X | | X X X O O X |
    | X X X | | X X X O O X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 87 O: 185 X-O: 0-0
    Cube: 2, O own cube
    X to play 42

    ---
    Tim Chow

    Obviously break up the points while the opponent is on the bar and his board is not tidied up. We want our checkers on the 7pt and 8pt to end up on our high inner board points for a safer bear off. This is a perfect roll to start doing that.

    Stick

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From ah....Clem@21:1/5 to Timothy Chow on Wed Jun 28 20:12:47 2023
    On 6/28/2023 8:27 AM, Timothy Chow wrote:
    XGID=aBbcBBCCB---A--a---cbab---:1:-1:1:42:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
     +13-14-15-16-17-18------19-20-21-22-23-24-+
     |       O          |   | O  O  O  O       | +---+
     |                  |   | O  O     O       | | 2 |
     |                  |   | O                | +---+
     |                  |   |                  |
     |                  |   |                  |
     |                  |BAR|                  |
     |                  | O |                  |
     |                  |   |                  |
     |                X |   | X        O       |
     |             X  X |   | X  X  X  O  O  X |
     | X           X  X |   | X  X  X  O  O  X |
     +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count  X: 87  O: 185 X-O: 0-0
    Cube: 2, O own cube
    X to play 42


    Why not clear the eight right now? "A point that's cleared is not to be feared."

    The blot on the 12 is in no danger, we're not in a hurry to bear off,
    and clearing the eight leaves us even-ended.

    I recall someone once observing that in bearins against contact "make
    sure you can play 65". It meets that criteria for what it's worth.

    8/4 8/6.

    --
    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 All on Fri Jun 30 08:44:44 2023
    XGID=aBbcBBCCB---A--a---cbab---:1:-1:1:42:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | O | | O O O O | +---+
    | | | O O O | | 2 |
    | | | O | +---+
    | | | |
    | | | |
    | |BAR| |
    | | O | |
    | | | |
    | X | | X O |
    | X X | | X X X O O X |
    | X X X | | X X X O O X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 87 O: 185 X-O: 0-0
    Cube: 2, O own cube
    X to play 42

    There are a couple of things to realize here. The first is that X
    is not too worried about leaving a blot on the 8pt. Since O is on
    the bar, there aren't too many rolls that hit it, and even if it is
    hit, that is not so bad for X, because it will likely improve his
    timing (this is what Walter Trice called the "early blot" principle).
    A second thing to remember is that particularly against a 2-3 backgame, clearing the bar point is usually a priority, because having too many
    checkers on the bar point can lead to awkward sixes later on. Finally,
    12/8 is the wrong idea, because keeping that checker further away gives
    X more flexibility when it comes to playing a 5 or a 6.

    1. Rollout¹ 12/10 8/4 eq:+0.119
    Player: 50.77% (G:34.46% B:2.74%)
    Opponent: 49.23% (G:5.29% B:0.20%)
    Confidence: ±0.012 (+0.106..+0.131) - [68.5%]

    2. Rollout¹ 8/4 7/5 eq:+0.114 (-0.004)
    Player: 50.95% (G:34.47% B:2.84%)
    Opponent: 49.05% (G:5.55% B:0.23%)
    Confidence: ±0.013 (+0.102..+0.127) - [31.5%]

    3. Rollout¹ 8/6 8/4 eq:+0.065 (-0.054)
    Player: 49.44% (G:33.66% B:2.40%)
    Opponent: 50.56% (G:5.53% B:0.20%)
    Confidence: ±0.014 (+0.051..+0.079) - [0.0%]

    4. Rollout¹ 12/8 7/5 eq:+0.026 (-0.093)
    Player: 49.01% (G:31.52% B:2.07%)
    Opponent: 50.99% (G:6.60% B:0.23%)
    Confidence: ±0.015 (+0.012..+0.041) - [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)
  • From Stick Rice@21:1/5 to Timothy Chow on Fri Jun 30 07:03:19 2023
    On Friday, June 30, 2023 at 8:44:48 AM UTC-4, Timothy Chow wrote:
    XGID=aBbcBBCCB---A--a---cbab---:1:-1:1:42:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | O | | O O O O | +---+
    | | | O O O | | 2 |
    | | | O | +---+
    | | | |
    | | | |
    | |BAR| |
    | | O | |
    | | | |
    | X | | X O |
    | X X | | X X X O O X |
    | X X X | | X X X O O X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 87 O: 185 X-O: 0-0
    Cube: 2, O own cube
    X to play 42
    There are a couple of things to realize here. The first is that X
    is not too worried about leaving a blot on the 8pt. Since O is on
    the bar, there aren't too many rolls that hit it, and even if it is
    hit, that is not so bad for X, because it will likely improve his
    timing (this is what Walter Trice called the "early blot" principle).
    A second thing to remember is that particularly against a 2-3 backgame, clearing the bar point is usually a priority, because having too many checkers on the bar point can lead to awkward sixes later on. Finally,
    12/8 is the wrong idea, because keeping that checker further away gives
    X more flexibility when it comes to playing a 5 or a 6.

    1. Rollout¹ 12/10 8/4 eq:+0.119
    Player: 50.77% (G:34.46% B:2.74%)
    Opponent: 49.23% (G:5.29% B:0.20%)
    Confidence: ±0.012 (+0.106..+0.131) - [68.5%]

    2. Rollout¹ 8/4 7/5 eq:+0.114 (-0.004)
    Player: 50.95% (G:34.47% B:2.84%)
    Opponent: 49.05% (G:5.55% B:0.23%)
    Confidence: ±0.013 (+0.102..+0.127) - [31.5%]

    3. Rollout¹ 8/6 8/4 eq:+0.065 (-0.054)
    Player: 49.44% (G:33.66% B:2.40%)
    Opponent: 50.56% (G:5.53% B:0.20%)
    Confidence: ±0.014 (+0.051..+0.079) - [0.0%]

    4. Rollout¹ 12/8 7/5 eq:+0.026 (-0.093)
    Player: 49.01% (G:31.52% B:2.07%)
    Opponent: 50.99% (G:6.60% B:0.23%)
    Confidence: ±0.015 (+0.012..+0.041) - [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

    It's not only sixes that be awkward later on against a 23/22 backgame, it's fives and fours.

    Stick

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