As Mike guessed, I Pottled. Not completely sure what's going on here, but I suspect that the "simple" explanation that many intermediates would give may be correct: bar/18 just allows White to attack.
I wanted to look at some variants here so the rollouts below are truncated to save CPU time.
         
 
        
 | | White is Player 2
score: 0
pip: 155 | Money session
Jacoby | pip: 148
score: 0
Blue is Player 1 |
|
| XGID=-----bE-C-C-dC-a-c-da----A:0:0:1:43:0:0:1:0:10 |
| Blue to play 43 |
| 1. | Rollout1 | Bar/22 8/4 | eq: -0.077 |
| Player:
Opponent: | 49.57% (G:7.31% B:0.25%)
50.43% (G:12.39% B:0.31%) | Conf: ± 0.009 (-0.086...-0.068)
Duration: 9 minutes 43 seconds |
|
| 2. | Rollout1 | Bar/22 6/2 | eq: -0.103 (-0.026) |
| Player:
Opponent: | 49.20% (G:7.23% B:0.25%)
50.80% (G:13.01% B:0.32%) | Conf: ± 0.009 (-0.112...-0.094)
Duration: 9 minutes 18 seconds |
|
| 3. | Rollout1 | Bar/22 10/6 | eq: -0.106 (-0.029) |
| Player:
Opponent: | 48.97% (G:7.30% B:0.25%)
51.03% (G:12.89% B:0.32%) | Conf: ± 0.009 (-0.115...-0.097)
Duration: 9 minutes 15 seconds |
|
| 4. | Rollout1 | Bar/18 | eq: -0.131 (-0.054) |
| Player:
Opponent: | 48.46% (G:6.36% B:0.23%)
51.54% (G:12.28% B:0.25%) | Conf: ± 0.007 (-0.138...-0.124)
Duration: 9 minutes 30 seconds |
|
| 5. | Rollout1 | Bar/21 6/3 | eq: -0.149 (-0.072) |
| Player:
Opponent: | 48.08% (G:7.09% B:0.25%)
51.92% (G:13.71% B:0.32%) | Conf: ± 0.009 (-0.158...-0.140)
Duration: 8 minutes 33 seconds |
|
| 6. | Rollout1 | Bar/21 13/10 | eq: -0.160 (-0.083) |
| Player:
Opponent: | 47.77% (G:6.78% B:0.24%)
52.23% (G:13.49% B:0.29%) | Conf: ± 0.009 (-0.169...-0.151)
Duration: 8 minutes 31 seconds |
|
| |
1 Truncated at 7 moves using 3 ply.
648 Games rolled with Variance Reduction.
Dice Seed: 46746
First 2 moves and cube decisions: 3 ply
Remaining moves: 2 ply, cube decisions: 3 ply
|
eXtreme Gammon Version: 1.21
| | White is Player 2
score: 0
pip: 154 | Money session
Jacoby | pip: 148
score: 0
Blue is Player 1 |
|
| XGID=-----bE-C-C-dC--ac-da----A:0:0:1:43:0:0:1:0:10 |
| Blue to play 43 |
| 1. | Rollout1 | Bar/21 13/10 | eq: -0.104 |
| Player:
Opponent: | 49.24% (G:6.98% B:0.26%)
50.76% (G:12.91% B:0.30%) | Conf: ± 0.009 (-0.113...-0.095)
Duration: 9 minutes 53 seconds |
|
| 2. | Rollout1 | Bar/21 6/3 | eq: -0.107 (-0.004) |
| Player:
Opponent: | 49.14% (G:7.09% B:0.25%)
50.86% (G:12.98% B:0.32%) | Conf: ± 0.009 (-0.116...-0.098)
Duration: 10 minutes 41 seconds |
|
| 3. | Rollout1 | Bar/18 | eq: -0.138 (-0.034) |
| Player:
Opponent: | 48.59% (G:5.95% B:0.22%)
51.41% (G:12.03% B:0.26%) | Conf: ± 0.008 (-0.146...-0.130)
Duration: 10 minutes 02 seconds |
|
| 4. | Rollout1 | Bar/22 8/4 | eq: -0.138 (-0.034) |
| Player:
Opponent: | 48.17% (G:7.38% B:0.28%)
51.83% (G:13.10% B:0.32%) | Conf: ± 0.009 (-0.147...-0.129)
Duration: 10 minutes 43 seconds |
|
| |
1 Truncated at 7 moves using 3 ply.
648 Games rolled with Variance Reduction.
Dice Seed: 2
First 2 moves and cube decisions: 3 ply
Remaining moves: 2 ply, cube decisions: 3 ply
|
eXtreme Gammon Version: 1.21
 
| | White is Player 2
score: 0
pip: 153 | Money session
Jacoby | pip: 148
score: 0
Blue is Player 1 |
|
| XGID=-----bE-C-C-dC-a-b-ea----A:0:0:1:43:0:0:1:0:10 |
| Blue to play 43 |
| 1. | Rollout1 | Bar/22 8/4 | eq: -0.043 |
| Player:
Opponent: | 50.65% (G:7.76% B:0.30%)
49.35% (G:12.40% B:0.30%) | Conf: ± 0.009 (-0.052...-0.034)
Duration: 15 minutes 22 seconds |
|
| 2. | Rollout1 | Bar/22 6/2 | eq: -0.051 (-0.008) |
| Player:
Opponent: | 50.67% (G:7.23% B:0.26%)
49.33% (G:12.71% B:0.30%) | Conf: ± 0.008 (-0.059...-0.043)
Duration: 14 minutes 24 seconds |
|
| 3. | Rollout1 | Bar/18 | eq: -0.066 (-0.023) |
| Player:
Opponent: | 50.23% (G:6.02% B:0.22%)
49.77% (G:11.58% B:0.22%) | Conf: ± 0.008 (-0.074...-0.058)
Duration: 15 minutes 15 seconds |
|
| 4. | Rollout1 | Bar/22 10/6 | eq: -0.067 (-0.024) |
| Player:
Opponent: | 50.17% (G:7.00% B:0.25%)
49.83% (G:12.45% B:0.29%) | Conf: ± 0.008 (-0.075...-0.059)
Duration: 12 minutes 50 seconds |
|
| 5. | Rollout1 | Bar/21 6/3 | eq: -0.093 (-0.050) |
| Player:
Opponent: | 49.63% (G:7.08% B:0.27%)
50.37% (G:13.53% B:0.29%) | Conf: ± 0.009 (-0.102...-0.084)
Duration: 12 minutes 43 seconds |
|
| |
1 Truncated at 7 moves using 3 ply.
648 Games rolled with Variance Reduction.
Dice Seed: 2
First 2 moves and cube decisions: 3 ply
Remaining moves: 2 ply, cube decisions: 3 ply
|
eXtreme Gammon Version: 1.21
| | White is Player 2
score: 0
pip: 157 | Money session
Jacoby | pip: 148
score: 0
Blue is Player 1 |
|
| XGID=----b-E-C-C-dC-a-c-da----A:0:0:1:43:0:0:1:0:10 |
| Blue to play 43 |
| 1. | Rollout1 | Bar/22 6/2 | eq: +0.002 |
| Player:
Opponent: | 51.65% (G:8.42% B:0.30%)
48.35% (G:12.42% B:0.32%) | Conf: ± 0.009 (-0.007...+0.011)
Duration: 8 minutes 10 seconds |
|
| 2. | Rollout1 | Bar/18 | eq: -0.011 (-0.013) |
| Player:
Opponent: | 51.45% (G:8.02% B:0.30%)
48.55% (G:12.26% B:0.28%) | Conf: ± 0.008 (-0.019...-0.003)
Duration: 8 minutes 30 seconds |
|
| |
1 Truncated at 7 moves using 3 ply.
648 Games rolled with Variance Reduction.
Dice Seed: 2
First 2 moves and cube decisions: 3 ply
Remaining moves: 2 ply, cube decisions: 3 ply
|
eXtreme Gammon Version: 1.21