XGID=-a-bBBC-D--BcB----acabb---:0:0:1:00:5:2:0:7:10

Score is X:5 O:2 7 pt.(s) match.
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X O | | O O O O |
| X | | O O O |
| | | O |
| | | |
| | | |
| |BAR| |
| | | |
| X | | |
| O X | | X |
| O X X | | X X X O |
| O X X | | X X X O O |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 116 O: 151 X-O: 5-2/7
Cube: 1
X on roll, cube action

---
Tim Chow

XGID=-a-bBBC-D--BcB----acabb---:0:0:1:00:5:2:0:7:10

Score is X:5 O:2 7 pt.(s) match.
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X O | | O O O O |
| X | | O O O |
| | | O |
| | | |
| | | |
| |BAR| |
| | | |
| X | | |
| O X | | X |
| O X X | | X X X O |
| O X X | | X X X O O |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 116 O: 151 X-O: 5-2/7
Cube: 1
X on roll, cube action

When leading 2-away, one should be cautious about doubling when
gammons are still non-negligible. In a holding game, however, if
it's a clear double for money, then it's often a double ATS.

This is a holding game cube, and it's a big pass for money.
So I doubled. But XG says I made a huge mistake by doubling.
What I neglected was that despite its being a holding game, a
significant part of my equity comes from gammon wins, since O
has a third checker back. I kill these gammons by doubling,
and the extra checker back gives O additional winning chances.

In the variant, O's third checker back has been moved to her
midpoint. For money, this change is an improvement for O (though
XG says it's still a pass), but it's a downgrade ATS.

Analyzed in Rollout
No double
Player Winning Chances: 75.75% (G:18.18% B:1.35%)
Opponent Winning Chances: 24.25% (G:3.13% B:0.09%)
Double/Take
Player Winning Chances: 74.48% (G:29.05% B:2.30%)
Opponent Winning Chances: 25.52% (G:3.57% B:0.22%)

Cubeful Equities:
No double: +0.860
Double/Take: +0.698 (-0.162)
Double/Pass: +1.000 (+0.140)

Best Cube action: No double / Take
Percentage of wrong pass needed to make the double decision right: 53.5%

Rollout:
1296 Games rolled with Variance Reduction.
Dice Seed: 271828
Moves: 3-ply, cube decisions: XG Roller
Confidence No Double: ± 0.011 (+0.848..+0.871)
Confidence Double: ± 0.020 (+0.678..+0.717)

eXtreme Gammon Version: 2.19.211.pre-release, MET: Kazaross XG2

-------
Variant
-------

XGID=---bBBC-D--BdB----acabb---:0:0:1:00:5:2:0:7:10

Score is X:5 O:2 7 pt.(s) match.
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X O | | O O O O |
| X | | O O O |
| | | O |
| | | |
| | | |
| |BAR| |
| | | |
| O X | | |
| O X | | X |
| O X X | | X X X O |
| O X X | | X X X O |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 116 O: 140 X-O: 5-2/7
Cube: 1
X on roll, cube action

Analyzed in Rollout
No double
Player Winning Chances: 77.27% (G:7.17% B:0.26%)
Opponent Winning Chances: 22.73% (G:1.81% B:0.01%)
Double/Take
Player Winning Chances: 78.06% (G:8.84% B:0.41%)
Opponent Winning Chances: 21.94% (G:1.72% B:0.03%)

Cubeful Equities:
No double: +0.920 (-0.080)
Double/Take: +1.046 (+0.046)
Double/Pass: +1.000

Best Cube action: Double / Pass

Rollout:
1296 Games rolled with Variance Reduction.
Dice Seed: 271828
Moves: 3-ply, cube decisions: XG Roller
Confidence No Double: ± 0.010 (+0.910..+0.931)
Confidence Double: ± 0.014 (+1.032..+1.061)

eXtreme Gammon Version: 2.19.211.pre-release, MET: Kazaross XG2

---
Tim Chow