But looking further down in the same match, game 3, you decide to take when doubled in a dubious 2-5 backgame. (at this point, Jason have missed 7 cubes in that particular game). Score is 6-0/9 in your favor, and you risk a gammon at the rate of about 20%.
The position is a proper double, and a pass according to XG. It's by no means a big pass, only a 0,027 error, but if you were going to adjust anything in your game from low PR towards winning - this is exactly the place to do so (in my eyes).
I have done a few rollouts of backgame cube actions with XGR+ checker plays and cube decisions, search interval huge. What I noticed is that XG evaluation of backgame cube decisions is way off. It grossly undervalues chances of the backgame player. Perhaps due to its known weakness in containment game.
I have not done rollouts for that particular game, but I believe they might turn all those "missed cubes" by Jason into proper non-doubles and Mochy's "small pass" into a huge take.
Here is a sample of what I did some time ago to compare different rollout settings. Anything lower than XGR+/XGR+ is quite a bit off. Notice that changing search interval for 4-ply checker play has zero effect -- meaning XG does not play 4-ply much better than 3-ply for backgames.
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| XGID=-bbDDDC-----------cbbbb---:0:0:1:00:0:0:3:0:10 | |||||
| Blue on roll, cube action? | |||||
| Analyzed in XG Roller++ | No double | Double/Take |
| Player Winning Chances: | 64.90% (G:37.58% B:8.07%) | 65.91% (G:38.04% B:8.04%) |
| Opponent Winning Chances: | 35.10% (G:0.00% B:0.00%) | 34.09% (G:0.00% B:0.00%) |
| Cubeless Equities | +0.755 | +1.558 |
| Cubeful Equities | ||
| No double: | +1.000 | |
| Double/Take: | +1.306 (+0.306) | |
| Double/Pass: | +1.000 | |
| Best Cube action: Double / Pass | ||
eXtreme Gammon Version: 2.10
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| ||||
| XGID=-bbDDDC-----------cbbbb---:0:0:1:00:0:0:3:0:10 | |||||
| Blue on roll, cube action? | |||||
| Analyzed in Rollout | No double | Double/Take |
| Player Winning Chances: | 64.76% (G:37.10% B:8.00%) | 64.72% (G:37.24% B:8.31%) |
| Opponent Winning Chances: | 35.24% (G:0.00% B:0.00%) | 35.28% (G:0.00% B:0.00%) |
| Cubeless Equities | +0.746 | +1.500 |
| Cubeful Equities | ||
| No double: | +0.970 (-0.030) | ±0.012 (+0.958..+0.981) |
| Double/Take: | +1.176 (+0.176) | ±0.025 (+1.151..+1.201) |
| Double/Pass: | +1.000 | |
| Best Cube action: Double / Pass | ||
| Rollout details | ||
| 1296 Games rolled with Variance Reduction. Dice Seed: 31641692 Moves: 3-ply, cube decisions: XG Roller | ||
| Double Decision confidence: | 100.0% | |
| Take Decision confidence: | 100.0% | |
| Duration: 1 minute 45 seconds | ||
eXtreme Gammon Version: 2.10
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| ||||
| XGID=-bbDDDC-----------cbbbb---:0:0:1:00:0:0:3:0:10 | |||||
| Blue on roll, cube action? | |||||
| Analyzed in Rollout | No double | Double/Take |
| Player Winning Chances: | 64.48% (G:37.02% B:7.87%) | 63.79% (G:37.00% B:8.06%) |
| Opponent Winning Chances: | 35.52% (G:0.00% B:0.00%) | 36.21% (G:0.00% B:0.00%) |
| Cubeless Equities | +0.739 | +1.453 |
| Cubeful Equities | ||
| No double: | +0.968 (-0.032) | ±0.006 (+0.962..+0.975) |
| Double/Take: | +1.121 (+0.121) | ±0.019 (+1.102..+1.140) |
| Double/Pass: | +1.000 | |
| Best Cube action: Double / Pass | ||
| Rollout details | ||
| 1296 Games rolled with Variance Reduction. Dice Seed: 31641692 Moves: 4-ply, cube decisions: XG Roller+ | ||
| Double Decision confidence: | 100.0% | |
| Take Decision confidence: | 100.0% | |
| Duration: 19 minutes 49 seconds | ||
eXtreme Gammon Version: 2.10
|
| ||||
| XGID=-bbDDDC-----------cbbbb---:0:0:1:00:0:0:3:0:10 | |||||
| Blue on roll, cube action? | |||||
| Analyzed in Rollout | No double | Double/Take |
| Player Winning Chances: | 64.48% (G:37.02% B:7.87%) | 63.71% (G:36.99% B:8.05%) |
| Opponent Winning Chances: | 35.52% (G:0.00% B:0.00%) | 36.29% (G:0.00% B:0.00%) |
| Cubeless Equities | +0.739 | +1.449 |
| Cubeful Equities | ||
| No double: | +0.968 (-0.032) | ±0.006 (+0.962..+0.975) |
| Double/Take: | +1.117 (+0.117) | ±0.019 (+1.099..+1.136) |
| Double/Pass: | +1.000 | |
| Best Cube action: Double / Pass | ||
| Rollout details | ||
| 1296 Games rolled with Variance Reduction. Dice Seed: 31641692 Moves: 4-ply, cube decisions: XG Roller+ Search interval: Large | ||
| Double Decision confidence: | 100.0% | |
| Take Decision confidence: | 100.0% | |
| Duration: 21 minutes 58 seconds | ||
eXtreme Gammon Version: 2.10
|
| ||||
| XGID=-bbDDDC-----------cbbbb---:0:0:1:00:0:0:3:0:10 | |||||
| Blue on roll, cube action? | |||||
| Analyzed in Rollout | No double | Double/Take |
| Player Winning Chances: | 64.48% (G:37.02% B:7.87%) | 63.73% (G:37.01% B:8.04%) |
| Opponent Winning Chances: | 35.52% (G:0.00% B:0.00%) | 36.27% (G:0.00% B:0.00%) |
| Cubeless Equities | +0.739 | +1.450 |
| Cubeful Equities | ||
| No double: | +0.968 (-0.032) | ±0.006 (+0.962..+0.975) |
| Double/Take: | +1.121 (+0.121) | ±0.019 (+1.102..+1.139) |
| Double/Pass: | +1.000 | |
| Best Cube action: Double / Pass | ||
| Rollout details | ||
| 1296 Games rolled with Variance Reduction. Dice Seed: 31641692 Moves: 4-ply, cube decisions: XG Roller+ Search interval: Huge | ||
| Double Decision confidence: | 100.0% | |
| Take Decision confidence: | 100.0% | |
| Duration: 24 minutes 24 seconds | ||
eXtreme Gammon Version: 2.10
|
| ||||
| XGID=-bbDDDC-----------cbbbb---:0:0:1:00:0:0:3:0:10 | |||||
| Blue on roll, cube action? | |||||
| Analyzed in Rollout | No double | Double/Take |
| Player Winning Chances: | 64.21% (G:36.84% B:7.73%) | 63.70% (G:36.79% B:7.92%) |
| Opponent Winning Chances: | 35.79% (G:0.00% B:0.00%) | 36.30% (G:0.00% B:0.00%) |
| Cubeless Equities | +0.730 | +1.442 |
| Cubeful Equities | ||
| No double: | +0.967 (-0.033) | ±0.007 (+0.960..+0.974) |
| Double/Take: | +1.103 (+0.103) | ±0.019 (+1.084..+1.122) |
| Double/Pass: | +1.000 | |
| Best Cube action: Double / Pass | ||
| Rollout details | ||
| 1296 Games rolled with Variance Reduction. Dice Seed: 31641692 Moves and cube decisions: XG Roller+ | ||
| Double Decision confidence: | 100.0% | |
| Take Decision confidence: | 100.0% | |
| Duration: 1 hour 31 minutes | ||
eXtreme Gammon Version: 2.10
|
| ||||
| XGID=-bbDDDC-----------cbbbb---:0:0:1:00:0:0:3:0:10 | |||||
| Blue on roll, cube action? | |||||
| Analyzed in Rollout | No double | Double/Take |
| Player Winning Chances: | 63.93% (G:36.65% B:7.64%) | 63.65% (G:36.84% B:7.88%) |
| Opponent Winning Chances: | 36.07% (G:0.00% B:0.00%) | 36.35% (G:0.00% B:0.00%) |
| Cubeless Equities | +0.721 | +1.440 |
| Cubeful Equities | ||
| No double: | +0.965 (-0.035) | ±0.007 (+0.958..+0.972) |
| Double/Take: | +1.099 (+0.099) | ±0.020 (+1.079..+1.119) |
| Double/Pass: | +1.000 | |
| Best Cube action: Double / Pass | ||
| Rollout details | ||
| 1296 Games rolled with Variance Reduction. Dice Seed: 31641692 Moves and cube decisions: XG Roller+ Search interval: Large | ||
| Double Decision confidence: | 100.0% | |
| Take Decision confidence: | 100.0% | |
| Duration: 1 hour 53 minutes | ||
eXtreme Gammon Version: 2.10
|
| ||||
| XGID=-bbDDDC-----------cbbbb---:0:0:1:00:0:0:3:0:10 | |||||
| Blue on roll, cube action? | |||||
| Analyzed in Rollout | No double | Double/Take |
| Player Winning Chances: | 63.96% (G:36.66% B:7.64%) | 63.60% (G:36.63% B:7.92%) |
| Opponent Winning Chances: | 36.04% (G:0.00% B:0.00%) | 36.40% (G:0.00% B:0.00%) |
| Cubeless Equities | +0.722 | +1.435 |
| Cubeful Equities | ||
| No double: | +0.957 (-0.043) | ±0.009 (+0.948..+0.966) |
| Double/Take: | +1.094 (+0.094) | ±0.021 (+1.073..+1.116) |
| Double/Pass: | +1.000 | |
| Best Cube action: Double / Pass | ||
| Rollout details | ||
| 1296 Games rolled with Variance Reduction. Dice Seed: 24617919 Moves and cube decisions: XG Roller+ Search interval: Huge | ||
| Double Decision confidence: | 100.0% | |
| Take Decision confidence: | 100.0% | |
| Duration: 2 hours 17 minutes | ||
eXtreme Gammon Version: 2.10
About 0.2 in relative equity difference regarding the pass decision between XGR++ evaluation and XGR+/XGR+ rollout.