The choice is between the attacking play 9/7(2) 6/4(2), the defensive play 24/20(2), and then there is a middling play 24/22(2) 6/4(2). Robertie suggest the middling play, but both attacking and defensive plays are so strong that the choice should really be between these two.
          
 
          
 | | White is Player 2
score: 0
pip: 151 | Unlimited Game
Jacoby | pip: 163
score: 0
Blue is Player 1 |
|
| XGID=-b----E-CBB-b---acbe---AB-:0:0:1:22:0:0:1:0:10 |
| Blue to play 22 |
| 1. | Rollout1 | 9/7(2) 6/4(2) | eq: +0.123 |
| Player:
Opponent: | 53.02% (G:16.97% B:1.05%)
46.98% (G:14.97% B:1.00%) | Conf.: ± 0.006 (+0.117...+0.129) - [100.0%]
Duration: 41 minutes 49 seconds |
|
| 2. | Rollout1 | 24/20(2) | eq: +0.106 (-0.017) |
| Player:
Opponent: | 51.43% (G:14.42% B:0.53%)
48.57% (G:9.55% B:0.38%) | Conf.: ± 0.005 (+0.101...+0.111) - [0.0%]
Duration: 58 minutes 17 seconds |
|
| 3. | Rollout1 | 24/22(2) 6/4(2) | eq: +0.105 (-0.019) |
| Player:
Opponent: | 51.65% (G:16.84% B:0.85%)
48.35% (G:12.72% B:0.60%) | Conf.: ± 0.006 (+0.099...+0.110) - [0.0%]
Duration: 50 minutes 40 seconds |
|
| |
1 10368 Games rolled with Variance Reduction.
Dice Seed: 94782038
Moves: 3-ply, cube decisions: XG Roller
|
eXtreme Gammon Version: 2.10
Three self-explanatory AtS rollouts:
| | White is Player 2
score: 0
pip: 151 | | 1 point match | pip: 163
score: 0
Blue is Player 1 |
|
| XGID=-b----E-CBB-b---acbe---AB-:0:0:1:22:0:0:0:1:10 |
| Blue to play 22 |
| 1. | Rollout1 | 9/7(2) 6/4(2) | eq: +0.063 |
| Player:
Opponent: | 53.17% (G:18.86% B:3.32%)
46.83% (G:16.89% B:3.54%) | Conf.: ± 0.005 (+0.059...+0.068) - [100.0%]
Duration: 6 minutes 23 seconds |
|
| 2. | Rollout1 | 24/20(2) | eq: +0.031 (-0.033) |
| Player:
Opponent: | 51.54% (G:15.43% B:1.30%)
48.46% (G:13.02% B:1.17%) | Conf.: ± 0.004 (+0.027...+0.035) - [0.0%]
Duration: 6 minutes 49 seconds |
|
| 3. | Rollout1 | 24/22(2) 6/4(2) | eq: +0.028 (-0.036) |
| Player:
Opponent: | 51.39% (G:18.64% B:2.96%)
48.61% (G:15.60% B:1.65%) | Conf.: ± 0.004 (+0.024...+0.032) - [0.0%]
Duration: 6 minutes 37 seconds |
|
| |
1 2592 Games rolled with Variance Reduction.
Dice Seed: 94782038
Moves: 3-ply, cube decisions: XG Roller
|
eXtreme Gammon Version: 2.10, MET: Kazaross XG2
| | White is Player 2
score: 0
pip: 151 | 2 point match
Crawford | pip: 163
score: 1
Blue is Player 1 |
|
| XGID=-b----E-CBB-b---acbe---AB-:0:0:1:22:1:0:1:2:10 |
| Blue to play 22 |
| 1. | Rollout1 | 24/20(2) | eq: -0.151 |
| Player:
Opponent: | 50.34% (G:14.12% B:1.47%)
49.66% (G:7.88% B:0.52%) | Conf.: ± 0.007 (-0.158...-0.144) - [100.0%]
Duration: 2 minutes 59 seconds |
|
| 2. | Rollout1 | 24/22(2) 6/4(2) | eq: -0.225 (-0.074) |
| Player:
Opponent: | 50.53% (G:18.17% B:2.63%)
49.47% (G:11.79% B:1.10%) | Conf.: ± 0.008 (-0.233...-0.217) - [0.0%]
Duration: 2 minutes 53 seconds |
|
| 3. | Rollout1 | 9/7(2) 6/4(2) | eq: -0.237 (-0.087) |
| Player:
Opponent: | 52.43% (G:18.22% B:3.13%)
47.57% (G:14.30% B:2.65%) | Conf.: ± 0.008 (-0.245...-0.229) - [0.0%]
Duration: 2 minutes 40 seconds |
|
| |
1 1296 Games rolled with Variance Reduction.
Dice Seed: 94782038
Moves: 3-ply, cube decisions: XG Roller
|
eXtreme Gammon Version: 2.10, MET: Kazaross XG2
| | White is Player 2
score: 1
pip: 151 | 2 point match
Crawford | pip: 163
score: 0
Blue is Player 1 |
|
| XGID=-b----E-CBB-b---acbe---AB-:0:0:1:22:0:1:1:2:10 |
| Blue to play 22 |
| 1. | Rollout1 | 9/7(2) 6/4(2) | eq: +0.414 |
| Player:
Opponent: | 53.55% (G:17.18% B:2.52%)
46.45% (G:17.22% B:3.67%) | Conf.: ± 0.006 (+0.408...+0.421) - [100.0%]
Duration: 5 minutes 17 seconds |
|
| 2. | Rollout1 | 24/22(2) 6/4(2) | eq: +0.383 (-0.032) |
| Player:
Opponent: | 51.85% (G:17.28% B:1.94%)
48.15% (G:16.05% B:1.49%) | Conf.: ± 0.006 (+0.377...+0.389) - [0.0%]
Duration: 5 minutes 27 seconds |
|
| 3. | Rollout2 | 24/20(2) | eq: +0.333 (-0.081) |
| Player:
Opponent: | 51.77% (G:14.88% B:1.10%)
48.23% (G:13.35% B:1.05%) | Conf.: ± 0.008 (+0.325...+0.341) - [0.0%]
Duration: 2 minutes 58 seconds |
|
| |
1 2592 Games rolled with Variance Reduction.
Dice Seed: 94782038
Moves: 3-ply, cube decisions: XG Roller
2 1296 Games rolled with Variance Reduction.
Dice Seed: 94782038
Moves: 3-ply, cube decisions: XG Roller
|
eXtreme Gammon Version: 2.10, MET: Kazaross XG2
Now, let's see how changes to white forward position affect the outcome.
 
| | White is Player 2
score: 0
pip: 152 | Unlimited Game
Jacoby | pip: 163
score: 0
Blue is Player 1 |
|
| XGID=-b----E-CBB-b---accd---AB-:0:0:1:22:0:0:1:0:10 |
| Blue to play 22 |
| 1. | Rollout1 | 24/20(2) | eq: +0.067 |
| Player:
Opponent: | 50.29% (G:13.97% B:0.49%)
49.71% (G:9.14% B:0.36%) | Conf.: ± 0.014 (+0.053...+0.082) - [100.0%]
Duration: 7 minutes 37 seconds |
|
| 2. | Rollout1 | 24/22(2) 6/4(2) | eq: -0.029 (-0.096) |
| Player:
Opponent: | 48.36% (G:15.57% B:0.80%)
51.64% (G:13.79% B:0.71%) | Conf.: ± 0.015 (-0.044...-0.014) - [0.0%]
Duration: 6 minutes 22 seconds |
|
| 3. | Rollout1 | 9/7(2) 6/4(2) | eq: -0.049 (-0.116) |
| Player:
Opponent: | 49.11% (G:15.69% B:1.00%)
50.89% (G:16.69% B:1.11%) | Conf.: ± 0.018 (-0.067...-0.031) - [0.0%]
Duration: 5 minutes 29 seconds |
|
| |
1 1296 Games rolled with Variance Reduction.
Dice Seed: 39609970
Moves: 3-ply, cube decisions: XG Roller
|
eXtreme Gammon Version: 2.10
| | White is Player 2
score: 0
pip: 153 | Unlimited Game
Jacoby | pip: 163
score: 0
Blue is Player 1 |
|
| XGID=-b----E-CBB-b---adbd---AB-:0:0:1:22:0:0:1:0:10 |
| Blue to play 22 |
| 1. | Rollout1 | 24/20(2) | eq: +0.094 |
| Player:
Opponent: | 51.02% (G:14.25% B:0.48%)
48.98% (G:9.08% B:0.36%) | Conf.: ± 0.009 (+0.086...+0.103) - [100.0%]
Duration: 30 minutes 36 seconds |
|
| 2. | Rollout1 | 9/7(2) 6/4(2) | eq: +0.062 (-0.032) |
| Player:
Opponent: | 51.31% (G:16.61% B:1.06%)
48.69% (G:15.21% B:1.00%) | Conf.: ± 0.008 (+0.054...+0.071) - [0.0%]
Duration: 21 minutes 37 seconds |
|
| 3. | Rollout2 | 24/22(2) 6/4(2) | eq: +0.037 (-0.058) |
| Player:
Opponent: | 50.04% (G:16.50% B:0.79%)
49.96% (G:12.91% B:0.62%) | Conf.: ± 0.012 (+0.024...+0.049) - [0.0%]
Duration: 13 minutes 02 seconds |
|
| |
1 5184 Games rolled with Variance Reduction.
Dice Seed: 39609970
Moves: 3-ply, cube decisions: XG Roller
2 2592 Games rolled with Variance Reduction.
Dice Seed: 39609970
Moves: 3-ply, cube decisions: XG Roller
|
eXtreme Gammon Version: 2.10
| | White is Player 2
score: 0
pip: 155 | Unlimited Game
Jacoby | pip: 163
score: 0
Blue is Player 1 |
|
| XGID=-b----E-CBB-b--aacbd---AB-:0:0:1:22:0:0:1:0:10 |
| Blue to play 22 |
| 1. | Rollout1 | 24/20(2) | eq: +0.064 |
| Player:
Opponent: | 50.30% (G:14.37% B:0.64%)
49.70% (G:9.62% B:0.43%) | Conf.: ± 0.014 (+0.050...+0.079) - [100.0%]
Duration: 8 minutes 00 second |
|
| 2. | Rollout1 | 24/22(2) 6/4(2) | eq: -0.119 (-0.184) |
| Player:
Opponent: | 46.32% (G:14.72% B:0.81%)
53.68% (G:14.45% B:0.73%) | Conf.: ± 0.021 (-0.141...-0.098) - [0.0%]
Duration: 6 minutes 17 seconds |
|
| 3. | Rollout1 | 9/7(2) 6/4(2) | eq: -0.123 (-0.188) |
| Player:
Opponent: | 47.06% (G:15.18% B:0.98%)
52.94% (G:17.44% B:1.19%) | Conf.: ± 0.016 (-0.140...-0.107) - [0.0%]
Duration: 5 minutes 18 seconds |
|
| |
1 1296 Games rolled with Variance Reduction.
Dice Seed: 39609970
Moves: 3-ply, cube decisions: XG Roller
|
eXtreme Gammon Version: 2.10
| | White is Player 2
score: 0
pip: 154 | Unlimited Game
Jacoby | pip: 163
score: 0
Blue is Player 1 |
|
| XGID=-b----E-CBB-b---bcbd---AB-:0:0:1:22:0:0:1:0:10 |
| Blue to play 22 |
| 1. | Rollout1 | 24/20(2) | eq: -0.073 |
| Player:
Opponent: | 46.73% (G:12.23% B:0.35%)
53.27% (G:8.90% B:0.34%) | Conf.: ± 0.015 (-0.088...-0.059) - [100.0%]
Duration: 8 minutes 15 seconds |
|
| 2. | Rollout1 | 9/7(2) 6/4(2) | eq: -0.149 (-0.075) |
| Player:
Opponent: | 46.19% (G:14.46% B:0.88%)
53.81% (G:16.53% B:1.00%) | Conf.: ± 0.017 (-0.166...-0.132) - [0.0%]
Duration: 5 minutes 50 seconds |
|
| 3. | Rollout1 | 24/22(2) 6/4(2) | eq: -0.294 (-0.220) |
| Player:
Opponent: | 41.34% (G:12.85% B:0.66%)
58.66% (G:14.07% B:0.64%) | Conf.: ± 0.016 (-0.309...-0.278) - [0.0%]
Duration: 6 minutes 19 seconds |
|
| |
1 1296 Games rolled with Variance Reduction.
Dice Seed: 39609970
Moves: 3-ply, cube decisions: XG Roller
|
eXtreme Gammon Version: 2.10
| | White is Player 2
score: 0
pip: 149 | Unlimited Game
Jacoby | pip: 163
score: 0
Blue is Player 1 |
|
| XGID=-b----E-CBB-b----cce---AB-:0:0:1:22:0:0:1:0:10 |
| Blue to play 22 |
| 1. | Rollout1 | 9/7(2) 6/4(2) | eq: +0.148 |
| Player:
Opponent: | 53.43% (G:16.88% B:0.89%)
46.57% (G:14.22% B:0.94%) | Conf.: ± 0.015 (+0.133...+0.164) - [100.0%]
Duration: 5 minutes 03 seconds |
|
| 2. | Rollout1 | 24/22(2) 6/4(2) | eq: +0.081 (-0.067) |
| Player:
Opponent: | 51.23% (G:16.05% B:0.86%)
48.77% (G:12.47% B:0.59%) | Conf.: ± 0.015 (+0.066...+0.096) - [0.0%]
Duration: 6 minutes 13 seconds |
|
| 3. | Rollout1 | 24/20(2) | eq: +0.056 (-0.092) |
| Player:
Opponent: | 50.25% (G:13.82% B:0.53%)
49.75% (G:9.84% B:0.35%) | Conf.: ± 0.014 (+0.042...+0.070) - [0.0%]
Duration: 7 minutes 21 seconds |
|
| |
1 1296 Games rolled with Variance Reduction.
Dice Seed: 39609970
Moves: 3-ply, cube decisions: XG Roller
|
eXtreme Gammon Version: 2.10
| | White is Player 2
score: 0
pip: 150 | Unlimited Game
Jacoby | pip: 163
score: 0
Blue is Player 1 |
|
| XGID=-b----E-CBB-b----cdd---AB-:0:0:1:22:0:0:1:0:10 |
| Blue to play 22 |
| 1. | Rollout1 | 9/7(2) 6/4(2) | eq: +0.074 |
| Player:
Opponent: | 51.63% (G:16.56% B:0.91%)
48.37% (G:15.25% B:1.04%) | Conf.: ± 0.008 (+0.066...+0.082) - [100.0%]
Duration: 21 minutes 05 seconds |
|
| 2. | Rollout1 | 24/20(2) | eq: +0.043 (-0.031) |
| Player:
Opponent: | 49.95% (G:13.51% B:0.45%)
50.05% (G:9.55% B:0.36%) | Conf.: ± 0.007 (+0.036...+0.051) - [0.0%]
Duration: 30 minutes 09 seconds |
|
| 3. | Rollout2 | 24/22(2) 6/4(2) | eq: +0.010 (-0.063) |
| Player:
Opponent: | 49.48% (G:15.30% B:0.74%)
50.52% (G:13.00% B:0.63%) | Conf.: ± 0.015 (-0.005...+0.025) - [0.0%]
Duration: 6 minutes 26 seconds |
|
| |
1 5184 Games rolled with Variance Reduction.
Dice Seed: 39609970
Moves: 3-ply, cube decisions: XG Roller
2 1296 Games rolled with Variance Reduction.
Dice Seed: 39609970
Moves: 3-ply, cube decisions: XG Roller
|
eXtreme Gammon Version: 2.10
The above variants show that the choice between attacking and defensive play is determined by the relative strength of the white forward position. The middling play is never right.
A little later I will post several more rollouts changing the position of two white checkers on the 24pt.