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  • Worst possible roll

    From Timothy Chow@21:1/5 to All on Fri Oct 14 08:44:16 2022
    Here's another unwelcome 55 in an otherwise excellent position.
    XG says it's my worst roll here. Some years ago, Othello made up
    a quiz consisting entirely of checker plays where the roll was the
    unluckiest possible roll. Like all his quizzes, it was fascinating.

    XGID=aBaBBCBAAA--b----Aacbcb---:1:-1:1:55:0:0:0:0:10

    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 O | +---+
    | | | O O O O | | 2 |
    | | | O O | +---+
    | | | |
    | | | |
    | |BAR| |
    | | O | |
    | | | |
    | | | X |
    | O | | X X X X X |
    | O X X X | | X X X X O X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 84 O: 127 X-O: 0-0
    Cube: 2, O own cube
    X to play 55

    ---
    Tim Chow

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  • From pepstein5@gmail.com@21:1/5 to Tim Chow on Fri Oct 14 07:47:13 2022
    On Friday, October 14, 2022 at 1:44:20 PM UTC+1, Tim Chow wrote:
    Here's another unwelcome 55 in an otherwise excellent position.
    XG says it's my worst roll here. Some years ago, Othello made up
    a quiz consisting entirely of checker plays where the roll was the
    unluckiest possible roll. Like all his quizzes, it was fascinating.

    XGID=aBaBBCBAAA--b----Aacbcb---:1:-1:1:55:0:0:0:0:10

    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 O | +---+
    | | | O O O O | | 2 |
    | | | O O | +---+
    | | | |
    | | | |
    | |BAR| |
    | | O | |
    | | | |
    | | | X |
    | O | | X X X X X |
    | O X X X | | X X X X O X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 84 O: 127 X-O: 0-0
    Cube: 2, O own cube
    X to play 55

    Unlucky rolls need not be difficult to play. Don't let the bad emotion cloud your judgment.
    To me, it seems natural to play 7/2*, but we should look at the safest option too, which
    leaves the opponent with no direct shots.
    So let's see what happens with the only play that does _not_ include 7/2*. Let's count the shots here. If the number of shots in this safe play is close to 11, then
    the timidity is not warranted.
    I see hits with 52/65/61. But it won't be easy to bring the blots home even after being missed.
    I think we need 7/2*. 6/1(2) also seems mandatory -- otherwise we leave too many shots.
    So, to me, the key choice is here. Do we play 8/3 or 9/4? Keeping the 8 point blot gives more
    covers for the 2, but it also gives the opponent a more dangerous attack if they hit back on the 2.
    I judge that this latter factor is more important because I can get enough cover numbers anyway.
    7/2* 6/1(2) 8/3 is my play.
    I feel a certain degree of psychological confidence in this play. It's not the case that any other play
    seems worth considering, and I can't make up my mind.
    However, there are plenty of times I've been confident and wrong.
    If I was a non-captain in a chouette team, and the captain didn't play this, I would be quite disappointed
    and frustrated (unless they could convince me).
    7/2* 6/1(2) 8/3.

    Paul

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  • From Stick Rice@21:1/5 to Tim Chow on Fri Oct 14 12:40:04 2022
    On Friday, October 14, 2022 at 8:44:20 AM UTC-4, Tim Chow wrote:
    Here's another unwelcome 55 in an otherwise excellent position.
    XG says it's my worst roll here. Some years ago, Othello made up
    a quiz consisting entirely of checker plays where the roll was the
    unluckiest possible roll. Like all his quizzes, it was fascinating.

    XGID=aBaBBCBAAA--b----Aacbcb---:1:-1:1:55:0:0:0:0:10

    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 O | +---+
    | | | O O O O | | 2 |
    | | | O O | +---+
    | | | |
    | | | |
    | |BAR| |
    | | O | |
    | | | |
    | | | X |
    | O | | X X X X X |
    | O X X X | | X X X X O X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 84 O: 127 X-O: 0-0
    Cube: 2, O own cube
    X to play 55

    ---
    Tim Chow

    Isn't this all 'forced'? You're obviously going to hit a second checker so 7/2*. You're obviously not going to leave two inner board blots so 6/1(2). With the remaining five it's obviously better to bring in another direct cover 9/4....?

    Stick

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  • From pepstein5@gmail.com@21:1/5 to Stick Rice on Fri Oct 14 13:02:13 2022
    On Friday, October 14, 2022 at 8:40:05 PM UTC+1, Stick Rice wrote:
    On Friday, October 14, 2022 at 8:44:20 AM UTC-4, Tim Chow wrote:
    Here's another unwelcome 55 in an otherwise excellent position.
    XG says it's my worst roll here. Some years ago, Othello made up
    a quiz consisting entirely of checker plays where the roll was the unluckiest possible roll. Like all his quizzes, it was fascinating.

    XGID=aBaBBCBAAA--b----Aacbcb---:1:-1:1:55:0:0:0:0:10

    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 O | +---+
    | | | O O O O | | 2 |
    | | | O O | +---+
    | | | |
    | | | |
    | |BAR| |
    | | O | |
    | | | |
    | | | X |
    | O | | X X X X X |
    | O X X X | | X X X X O X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 84 O: 127 X-O: 0-0
    Cube: 2, O own cube
    X to play 55

    ---
    Tim Chow
    Isn't this all 'forced'? You're obviously going to hit a second checker so 7/2*. You're obviously not going to leave two inner board blots so 6/1(2). With the remaining five it's obviously better to bring in another direct cover 9/4....?

    Not to me it wasn't. I played 8/3 instead of 9/4 because I didn't want to be too vulnerable if my opponent rehit me on the 2.

    Paul

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  • From Stick Rice@21:1/5 to peps...@gmail.com on Fri Oct 14 13:51:41 2022
    On Friday, October 14, 2022 at 4:02:14 PM UTC-4, peps...@gmail.com wrote:
    On Friday, October 14, 2022 at 8:40:05 PM UTC+1, Stick Rice wrote:
    On Friday, October 14, 2022 at 8:44:20 AM UTC-4, Tim Chow wrote:
    Here's another unwelcome 55 in an otherwise excellent position.
    XG says it's my worst roll here. Some years ago, Othello made up
    a quiz consisting entirely of checker plays where the roll was the unluckiest possible roll. Like all his quizzes, it was fascinating.

    XGID=aBaBBCBAAA--b----Aacbcb---:1:-1:1:55:0:0:0:0:10

    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 O | +---+
    | | | O O O O | | 2 |
    | | | O O | +---+
    | | | |
    | | | |
    | |BAR| |
    | | O | |
    | | | |
    | | | X |
    | O | | X X X X X |
    | O X X X | | X X X X O X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 84 O: 127 X-O: 0-0
    Cube: 2, O own cube
    X to play 55

    ---
    Tim Chow
    Isn't this all 'forced'? You're obviously going to hit a second checker so 7/2*. You're obviously not going to leave two inner board blots so 6/1(2). With the remaining five it's obviously better to bring in another direct cover 9/4....?
    Not to me it wasn't. I played 8/3 instead of 9/4 because I didn't want to be too vulnerable if my opponent rehit me on the 2.

    Paul

    So you're preparing for 11/36 instead of 25/36? Generally doesn't sound like a winning game plan.

    Stick

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  • From ah...Clem@21:1/5 to Timothy Chow on Sat Oct 15 09:57:38 2022
    On 10/14/2022 8:44 AM, Timothy Chow wrote:
    Here's another unwelcome 55 in an otherwise excellent position.
    XG says it's my worst roll here.  Some years ago, Othello made up
    a quiz consisting entirely of checker plays where the roll was the
    unluckiest possible roll.  Like all his quizzes, it was fascinating.

    XGID=aBaBBCBAAA--b----Aacbcb---:1:-1:1:55:0:0:0:0:10

    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  O       | +---+  |                  |   | O  O  O  O       | | 2 |
     |                  |   | O     O          | +---+
     |                  |   |                  |
     |                  |   |                  |
     |                  |BAR|                  |
     |                  | O |                  |
     |                  |   |                  |
     |                  |   |    X             |
     | O                |   | X  X  X  X     X |
     | O        X  X  X |   | X  X  X  X  O  X |  +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count  X: 84  O: 127 X-O: 0-0
    Cube: 2, O own cube
    X to play 55

    X will still be ahead in the race by a lot with O on the bar after this
    play, so seems to me that minimizing shots would be the right approach.
    So, I'll play 9/4 8/3 6/1(2).

    The other option would be to hit loose, clear the six point, and then
    either 9/4 or 8/3 for the fourth five. I don't think exposing two blots
    in the homeboard is correct.

    I'll minimize shots.

    (PS - been traveling for the last two weeks without usenet access hence
    the radio silence)

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    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Timothy Chow@21:1/5 to All on Sun Oct 16 08:49:02 2022
    XGID=aBaBBCBAAA--b----Aacbcb---:1:-1:1:55:0:0:0:0:10

    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 O | +---+
    | | | O O O O | | 2 |
    | | | O O | +---+
    | | | |
    | | | |
    | |BAR| |
    | | O | |
    | | | |
    | | | X |
    | O | | X X X X X |
    | O X X X | | X X X X O X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 84 O: 127 X-O: 0-0
    Cube: 2, O own cube
    X to play 55

    The "safe" play still leaves some shots from the bar, and we still have
    work to do even if missed. After putting the second checker up with
    7/2* 6/1(2), do we play 9/4 or 8/3? Like Paul, I focused only on O's
    good rolls from the bar. But in highly volatile positions, there's a
    basic principle one should follow: consider both the opponent's good
    rolls and the opponent's bad rolls, and weigh them against each other.
    If we're not hit (and the opponent doesn't roll 66), then we definitely
    gain a lot by having three builders for the 2pt. If we are hit, then
    it doesn't make all that much difference whether our remaining blot is
    on the 9pt or the 8pt. Furthermore, there are fewer hitting rolls than non-hitting rolls. So 9/4 is the play.

    1. Rollout¹ 9/4 7/2* 6/1(2) eq:+0.640
    Player: 71.52% (G:40.26% B:0.26%)
    Opponent: 28.48% (G:9.21% B:0.60%)
    Confidence: ±0.006 (+0.634..+0.646) - [100.0%]

    2. Rollout¹ 8/3 7/2* 6/1(2) eq:+0.527 (-0.112)
    Player: 68.47% (G:37.38% B:0.26%)
    Opponent: 31.53% (G:10.24% B:0.67%)
    Confidence: ±0.005 (+0.522..+0.533) - [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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