There are two reasons I posted this position. First, XGR++ puts 24/20(2) 13/9(2) ahead of running by 0.21, and this is a natural move you'd expect to make in this position:
         
 
        
 | | White is Player 2
score: 0
pip: 155 | Unlimited Game
Jacoby Beaver | pip: 157
score: 0
Blue is Player 1 |
|
| XGID=--B-b-D-B---cE-b-c-e----B-:0:0:1:44:0:0:3:0:10 |
| Blue to play 44 |
| 1. | XG Roller++ | 24/20(2) 13/9(2) | eq: +0.118 |
| Player:
Opponent: | 53.05% (G:9.12% B:0.26%)
46.95% (G:7.11% B:0.25%) | |
|
| 2. | XG Roller++ | 24/16(2) | eq: +0.097 (-0.021) |
| Player:
Opponent: | 53.88% (G:5.60% B:0.18%)
46.12% (G:7.97% B:0.21%) | |
|
eXtreme Gammon Version: 2.10
However, the rollout completely overturns this and puts running ahead by 0.024:
| | White is Player 2
score: 0
pip: 155 | Unlimited Game
Jacoby Beaver | pip: 157
score: 0
Blue is Player 1 |
|
| XGID=--B-b-D-B---cE-b-c-e----B-:0:0:1:44:0:0:3:0:10 |
| Blue to play 44 |
| 1. | Rollout1 | 24/16(2) | eq: +0.148 |
| Player:
Opponent: | 54.16% (G:5.82% B:0.24%)
45.84% (G:8.46% B:0.25%) | Conf.: ± 0.006 (+0.143...+0.154) - [100.0%]
Duration: 26 minutes 50 seconds |
|
| 2. | Rollout1 | 24/20(2) 13/9(2) | eq: +0.124 (-0.024) |
| Player:
Opponent: | 53.43% (G:9.32% B:0.31%)
46.57% (G:7.41% B:0.25%) | Conf.: ± 0.006 (+0.118...+0.130) - [0.0%]
Duration: 24 minutes 04 seconds |
|
| |
1 5184 Games rolled with Variance Reduction.
Dice Seed: 36914453
Moves: 3-ply, cube decisions: XG Roller
|
eXtreme Gammon Version: 2.10
So, my two reasons for posting this position are these: (1) I've never seen a rollout differ from XGR++ by 0.045 in an opening position; and (2) I don't understand why running is best here.