If you don't double and roll one of your 31 non-jokers, will White double? If yes, then Blue should double now. If not, then Blue should not double.
Should White double if Blue doesn't bear off all 3 checkers? The answer is yes. The reason is risk/risk+gain. The risk is the match winning chances lost by losing two points rather than one. Losing 1/2 points gives White 60%/50% MWC so the risk from doubling is 10%. Now the gain. If White wins 1/2 points his MWC are 81.5%/100% so the gain from doubling is 18.5%. R/R+G = 10/28.5 which is 35%. White wins 17/36 so it's a clear double in a last roll of the game position.
If Blue knows that White will double after the 31/36 non-jokers, then Blue should double now. Using the same R/R+G approach, we get: Don't double and lose this game and you'll lose the match with 0% MWC, do double and lose this game will also lose the match so the risk from doubling is 0. Now for the gain: Don't double and win this game gives you 50% MWC 31/36ths and 40% MWC 5/36ths of the time. Do double and win always gives you 50% MWC so the gain from doubling is an extra 10% MWC when you roll one of your 5 jokers. So doubling is risking nothing to gain a little bit.
If Blue knows that White won't double after one of Blue's immediate non-winners, then not doubling is better. Don't double and lose gives Blue 18.5% MWC, do double and lose loses the match with 0% MWC so the risk is 18.5%. Don't double and win gives Blue 40% MWC while double and win gives Blue 50% MWC so the gain is 10% Minimum doubling point is then 18.5/28.5, ~65%. Blue only wins around 60% here so not doubling is correct. I think lots of players would make the mistake of not doubling as White. They'd think something like "I'm ahead in the match and an underdog in the game so doubling can't be correct."
                  |
| ||||
| XGID=-AAA-----------------aa---:0:0:1:00:3:5:0:7:10 | |||||
| Blue on roll, cube action? | |||||
| Analyzed in Rollout | No double | Double/Take |
| Player Winning Chances: | 59.34% (G:0.00% B:0.00%) | 59.34% (G:0.00% B:0.00%) |
| Opponent Winning Chances: | 40.66% (G:0.00% B:0.00%) | 40.66% (G:0.00% B:0.00%) |
| Cubeless Equities | +0.187 | +0.033 |
| Cubeful Equities | ||
| No double: | -0.095 (-0.129) | ±0.000 (-0.095..-0.095) |
| Double/Take: | +0.033 | ±0.000 (+0.033..+0.033) |
| Double/Pass: | +1.000 (+0.967) | |
| Best Cube action: Double / Take | ||
| Rollout details | ||
| 1296 Games rolled with Variance Reduction. First 12 moves: 3-ply, cube decisions: XG Roller Remaining moves: 3-ply Red, cube decisions: 4-ply Search interval: Large | ||
| Double Decision confidence: | 100.0% | |
| Take Decision confidence: | 100.0% | |
| Duration: 0.2 second | ||
eXtreme Gammon Version: 2.10, MET: Kazaross XG2