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  • Is this a backgame?

    From Timothy Chow@21:1/5 to All on Sat Sep 18 19:25:22 2021
    XGID=-----bCC--bB-C--cbbbBbB---:0:0:1:52:0:0:0:0:10

    X:Player 1 O:Player 2
    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 X |
    | X O O O | | O X O X |
    | X O | | |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | X | | X |
    | X O X | | X O |
    | X O X | | X O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 184 O: 147 X-O: 0-0
    Cube: 1
    X to play 52

    ---
    Tim Chow

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From ah...Clem@21:1/5 to Timothy Chow on Mon Sep 20 10:33:48 2021
    On 9/18/2021 7:25 PM, Timothy Chow wrote:
    XGID=-----bCC--bB-C--cbbbBbB---:0:0:1:52:0:0:0:0:10

    X:Player 1   O:Player 2
    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  X       |
     | X        O  O  O |   | O  X  O  X       |
     | X        O       |   |                  |  |                  |   |                  |
     |                  |   |                  |
     |                  |BAR|                  |
     |                  |   |                  |
     |                  |   |                  |
     |                X |   | X                |  |    X  O        X |   | X  O             |  |    X  O        X |   | X  O             |  +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count  X: 184  O: 147 X-O: 0-0
    Cube: 1
    X to play 52

    I wouldn't call this a backgame. Not enough timing and O still has four checkers to bring around. "Mutual holding game" is more like it.

    And since it looks like a holding game, I'm not going to volunteer a
    shot. 13/6 for me, although Pottling with 22/15 looks sound and may be best.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Timothy Chow@21:1/5 to All on Tue Sep 21 22:18:44 2021
    XGID=-----bCC--bB-C--cbbbBbB---:0:0:1:52:0:0:0:0:10

    X:Player 1 O:Player 2
    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 X |
    | X O O O | | O X O X |
    | X O | | |
    | | | |
    | | | |
    | |BAR| |
    | | | |
    | | | |
    | X | | X |
    | X O X | | X O |
    | X O X | | X O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 184 O: 147 X-O: 0-0
    Cube: 1
    X to play 52

    Here, 13/6 looks plausible, but XG favors either jumping a checker
    over O's prime with 22/15 (despite being 30 pips down after the roll)
    or the odd-looking 13/8 6/4. Actually, I think I understand the
    rationale behind 13/8 6/4---X is playing a two-way game, meaning that
    he can fall back on a backgame if necessary, and can afford to play aggressively. It's 22/15 that still looks odd to me, since I would
    think that X wants to keep that back anchor for more contact.

    1. Rollout¹ 22/15 eq:-0.516
    Player: 37.82% (G:7.39% B:0.32%)
    Opponent: 62.18% (G:16.73% B:0.58%)
    Confidence: ±0.018 (-0.534..-0.498) - [50.1%]

    2. Rollout¹ 13/8 6/4 eq:-0.516
    Player: 38.45% (G:7.75% B:0.31%)
    Opponent: 61.55% (G:17.74% B:0.58%)
    Confidence: ±0.017 (-0.533..-0.499) - [49.9%]

    3. Rollout¹ 13/6 eq:-0.604 (-0.088)
    Player: 35.27% (G:7.05% B:0.30%)
    Opponent: 64.73% (G:15.57% B:0.46%)
    Confidence: ±0.016 (-0.619..-0.588) - [0.0%]

    ¹ 1296 Games rolled with Variance Reduction.
    Dice Seed: 271828
    Moves: 3-ply, cube decisions: XG Roller

    eXtreme Gammon Version: 2.19.207.pre-release

    ---
    Tim Chow

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Timothy Chow@21:1/5 to All on Tue Nov 15 08:21:24 2022
    XGID=--Bbb-DCB---bB---aaeB-b---:0:0:1:51:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X O O | | O X O |
    | X | | O X O |
    | | | O |
    | | | O |
    | | | O |
    | |BAR| |
    | | | |
    | | | X |
    | X | | X |
    | O X X | | X O O X |
    | O X X | | X O O X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 131 O: 163 X-O: 0-0
    Cube: 1
    X to play 51

    ---
    Tim Chow

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From ah...Clem@21:1/5 to Timothy Chow on Tue Nov 15 13:44:13 2022
    On 11/15/2022 8:21 AM, Timothy Chow wrote:
    XGID=--Bbb-DCB---bB---aaeB-b---:0:0:1:51:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game  +13-14-15-16-17-18------19-20-21-22-23-24-+
     | X           O  O |   | O  X     O       |
     | X                |   | O  X     O       |  |                  |   | O                |
     |                  |   | O                |
     |                  |   | O                |
     |                  |BAR|                  |
     |                  |   |                  |
     |                  |   | X                |
     |                X |   | X                |  | O           X  X |   | X     O  O  X    |
     | O           X  X |   | X     O  O  X    |  +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count  X: 131  O: 163 X-O: 0-0
    Cube: 1
    X to play 51

    ~30 pips of timing does not a backgame make. So, I'd say no. If X hits another checker (which may or may not be correct) it could turn into
    one. Most likely it will turn into a 3 or 4 point holding game.

    But since X may not want to hit, O may not want to hit either (where
    "want" is what XG would do, not necessarily the patzer across the
    board). That gives X the opportunity to run off the anchor, so I'll do
    that. Not sure it's right, but up by ~30 pips I want (in the normal
    sense of the word) to press the race advantage. 20/14.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Timothy Chow@21:1/5 to All on Thu Nov 17 09:19:41 2022
    XGID=--Bbb-DCB---bB---aaeB-b---:0:0:1:51:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X O O | | O X O |
    | X | | O X O |
    | | | O |
    | | | O |
    | | | O |
    | |BAR| |
    | | | |
    | | | X |
    | X | | X |
    | O X X | | X O O X |
    | O X X | | X O O X |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 131 O: 163 X-O: 0-0
    Cube: 1
    X to play 51

    I have no strong opinion about whether this is a backgame. Regardless,
    X's position is currently rather inflexible, but he does have the golden anchor, so now is a reasonable time to make a bid for better structure.
    The bot play of 13/8 6/5 risks a lot of shots, but unless O rolls 11 or
    22, she will have to break a point to hit, giving X ample opportunity to counterattack, at a moment when O's board isn't very strong and she
    already has two blots lying around. And of course, if O doesn't hit,
    then X has excellent chances of making his 5pt and thereby significantly improving his position.

    1. Rollout¹ 13/8 6/5 eq:+0.473
    Player: 60.42% (G:19.95% B:0.97%)
    Opponent: 39.58% (G:8.67% B:0.32%)
    Confidence: ±0.016 (+0.457..+0.488) - [100.0%]

    2. Rollout¹ 6/1 2/1 eq:+0.396 (-0.076)
    Player: 58.46% (G:18.71% B:0.54%)
    Opponent: 41.54% (G:9.49% B:0.35%)
    Confidence: ±0.015 (+0.382..+0.411) - [0.0%]

    3. Rollout¹ 7/2 6/5 eq:+0.393 (-0.080)
    Player: 58.06% (G:19.19% B:0.76%)
    Opponent: 41.94% (G:9.89% B:0.38%)
    Confidence: ±0.015 (+0.378..+0.408) - [0.0%]

    4. Rollout¹ 13/7 eq:+0.391 (-0.082)
    Player: 58.67% (G:17.05% B:0.58%)
    Opponent: 41.33% (G:8.95% B:0.34%)
    Confidence: ±0.014 (+0.377..+0.405) - [0.0%]

    5. Rollout¹ 6/5 6/1 eq:+0.378 (-0.095)
    Player: 58.20% (G:19.30% B:0.69%)
    Opponent: 41.80% (G:10.42% B:0.42%)
    Confidence: ±0.016 (+0.362..+0.395) - [0.0%]

    6. Rollout¹ 13/8 7/6 eq:+0.367 (-0.106)
    Player: 58.04% (G:16.82% B:0.58%)
    Opponent: 41.96% (G:9.02% B:0.34%)
    Confidence: ±0.013 (+0.354..+0.380) - [0.0%]

    7. Rollout¹ 13/8 2/1 eq:+0.352 (-0.120)
    Player: 57.94% (G:16.97% B:0.54%)
    Opponent: 42.06% (G:9.20% B:0.35%)
    Confidence: ±0.014 (+0.338..+0.367) - [0.0%]

    8. Rollout¹ 7/1 eq:+0.352 (-0.121)
    Player: 57.61% (G:18.11% B:0.55%)
    Opponent: 42.39% (G:10.01% B:0.38%)
    Confidence: ±0.014 (+0.337..+0.366) - [0.0%]

    ¹ 1296 Games rolled with Variance Reduction.
    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 Timothy Chow@21:1/5 to All on Tue Oct 24 08:53:09 2023
    XGID=---b-bE-C-B-bD---bbd-A-a--:0:0:1:54:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X O O | | O X O |
    | X O O | | O |
    | X | | O |
    | X | | O |
    | | | |
    | |BAR| |
    | | | X |
    | | | X |
    | X | | X |
    | O X X | | X O O |
    | O X X | | X O O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 147 O: 166 X-O: 0-0
    Cube: 1
    X to play 54

    ---
    Tim Chow

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Stick Rice@21:1/5 to Timothy Chow on Tue Oct 24 10:38:16 2023
    On Tuesday, October 24, 2023 at 8:53:12 AM UTC-4, Timothy Chow wrote:
    XGID=---b-bE-C-B-bD---bbd-A-a--:0:0:1:54:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X O O | | O X O |
    | X O O | | O |
    | X | | O |
    | X | | O |
    | | | |
    | |BAR| |
    | | | X |
    | | | X |
    | X | | X |
    | O X X | | X O O |
    | O X X | | X O O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 147 O: 166 X-O: 0-0
    Cube: 1
    X to play 54

    ---
    Tim Chow

    No.

    Stick

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Frank Berger@21:1/5 to All on Wed Oct 25 03:56:42 2023
    The points are unusual high and it lacks a race deficit.
    Maybe this is a backgame: XGID=---bBbDBC-B-bB---bbd---a--:0:0:1:54:2:4:0:11:10

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Timothy Chow@21:1/5 to All on Thu Oct 26 23:35:13 2023
    XGID=---b-bE-C-B-bD---bbd-A-a--:0:0:1:54:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X O O | | O X O |
    | X O O | | O |
    | X | | O |
    | X | | O |
    | | | |
    | |BAR| |
    | | | X |
    | | | X |
    | X | | X |
    | O X X | | X O O |
    | O X X | | X O O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 147 O: 166 X-O: 0-0
    Cube: 1
    X to play 54

    I didn't like the look of 6/2 but XG thinks that anything other than
    21/16 6/2 is horrible. Changing the spare distribution makes some
    difference, but not enough to swing the play.

    1. Rollout¹ 21/16 6/2 eq:+0.425
    Player: 61.20% (G:11.39% B:0.37%)
    Opponent: 38.80% (G:8.78% B:0.26%)
    Confidence: ±0.014 (+0.410..+0.439) - [100.0%]

    2. Rollout¹ 13/8 6/2 eq:+0.292 (-0.133)
    Player: 57.39% (G:13.47% B:0.50%)
    Opponent: 42.61% (G:11.23% B:0.28%)
    Confidence: ±0.016 (+0.275..+0.308) - [0.0%]

    3. Rollout¹ 21/16 13/9 eq:+0.262 (-0.163)
    Player: 57.29% (G:12.01% B:0.48%)
    Opponent: 42.71% (G:11.36% B:0.39%)
    Confidence: ±0.015 (+0.247..+0.276) - [0.0%]

    4. Rollout¹ 21/16 8/4 eq:+0.256 (-0.168)
    Player: 57.69% (G:11.43% B:0.46%)
    Opponent: 42.31% (G:11.83% B:0.37%)
    Confidence: ±0.015 (+0.242..+0.271) - [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

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

    XGID=---b-bD-D-B-bD---bbd-A-a--:0:0:1:54:0:0:0:0:10

    Score is X:0 O:0. Unlimited Game
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X O O | | O X O |
    | X O O | | O |
    | X | | O |
    | X | | O |
    | | | |
    | |BAR| |
    | | | |
    | X | | X |
    | X | | X |
    | O X X | | X O O |
    | O X X | | X O O |
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 149 O: 166 X-O: 0-0
    Cube: 1
    X to play 54

    1. Rollout¹ 21/16 6/2 eq:+0.416
    Player: 61.26% (G:10.78% B:0.39%)
    Opponent: 38.74% (G:8.67% B:0.26%)
    Confidence: ±0.019 (+0.396..+0.435) - [100.0%]

    2. Rollout¹ 21/16 8/4 eq:+0.355 (-0.061)
    Player: 59.96% (G:11.04% B:0.45%)
    Opponent: 40.04% (G:10.03% B:0.26%)
    Confidence: ±0.015 (+0.339..+0.370) - [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)