BGonline.org Forums

We know it's a cube - Variants

Posted By: Nack Ballard
Date: Monday, 26 January 2026, at 5:41 a.m.

In Response To: Position of the Day 01-20-25 - We know it's a cube - Rollout (Stick)

		White is Player 1 score: 0 pip: 179 Unlimited Game Jacoby Beaver pip: 159 score: 0 Blue is Player 2
XGID=-a-a-aE-Ca--cDa----bab-AbB:0:0:-1:00:0:0:3:0:10
Original Position: Double, Take

Analyzed in Rollout	No double	Double/Take
Player Winning Chances:	65.95% (G:32.88% B:1.20%)	66.37% (G:34.95% B:1.26%)
Opponent Winning Chances:	34.05% (G:7.13% B:0.31%)	33.63% (G:7.29% B:0.38%)
Cubeless Equities	+0.585	+1.225
Cubeful Equities
No double:	+0.786 (-0.173)	±0.011 (+0.774..+0.797)
Double/Take:	+0.959	±0.019 (+0.940..+0.978)
Double/Pass:	+1.000 (+0.041)
Best Cube action: Double / Take
Rollout details
1296 Games rolled with Variance Reduction. Moves: 3-ply, cube decisions: XG Roller
Double Decision confidence:		100.0%
Take Decision confidence:		100.0%
Duration: 1 minute 10 seconds

Above is Stick's rollout of the original position.

Below are two cube variants: one that contrasts with the original and the other a cusp.

Nack

		White is Player 2 score: 0 pip: 179 Unlimited Game Jacoby Beaver pip: 157 score: 0 Blue is Player 1
XGID=bBa-BAB--A--dC--Ac-eA-A-A-:0:0:1:00:0:0:3:0:10
Variant 1: Blue's 11pt checker is moved up 2 pips

Analyzed in Rollout	No double	Double/Take
Player Winning Chances:	66.83% (G:35.31% B:1.30%)	67.25% (G:36.69% B:1.26%)
Opponent Winning Chances:	33.17% (G:6.99% B:0.32%)	32.75% (G:7.27% B:0.37%)
Cubeless Equities	+0.630	+1.296
Cubeful Equities
No double:	+0.821 (-0.179)	±0.012 (+0.809..+0.834)
Double/Take:	+1.040 (+0.040)	±0.022 (+1.018..+1.062)
Double/Pass:	+1.000
Best Cube action: Double / Pass
Rollout details
1296 Games rolled with Variance Reduction. Dice Seed: 48226825 Moves: 3-ply, cube decisions: XG Roller
Double Decision confidence:		100.0%
Take Decision confidence:		100.0%
Duration: 32 minutes 16 seconds

eXtreme Gammon Version: 2.10

		White is Player 2 score: 0 pip: 179 Unlimited Game Jacoby Beaver pip: 161 score: 0 Blue is Player 1
XGID=bBa-BAB-----dD--Ac-eA-A-A-:0:0:1:00:0:0:3:0:10
Variant 2: Blue's 11pt checker is moved back 2 pips

Analyzed in Rollout	No double	Double/Take
Player Winning Chances:	61.90% (G:29.09% B:1.05%)	62.17% (G:29.97% B:1.04%)
Opponent Winning Chances:	38.10% (G:8.73% B:0.41%)	37.83% (G:8.78% B:0.42%)
Cubeless Equities	+0.448	+0.923
Cubeful Equities
No double:	+0.622	±0.006 (+0.616..+0.629)
Double/Take:	+0.621 (-0.002)	±0.008 (+0.613..+0.629)
Double/Pass:	+1.000 (+0.378)
Best Cube action: No double / Take
Percentage of wrong pass needed to make the double decision right: 0.4%
Rollout details
10368 Games rolled with Variance Reduction. Dice Seed: 79965847 Moves: 3-ply, cube decisions: XG Roller
Double Decision confidence:		61.5%
Take Decision confidence:		100.0%
Duration: 3 hours 23 minutes