XGID=-a-BBBB-B-ab-B---B-Ad-cbb-:1:1:1:00:0:0:0:0:10

X:Player 1 O:Player 2
Score is X:0 O:0. Unlimited Game
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X X | | X O O O O |
| X X | | O O O O |
| | | O O |
| | | O |
| | | |
| |BAR| |
| | | |
| | | |
| | | | +---+
| O X | | X X X X | | 2 |
| O O X | | X X X X O | +---+
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 131 O: 102 X-O: 0-0
Cube: 2, X own cube
X on roll, cube action

---
Tim Chow

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

XGID=-a-BBBB-B-ab-B---B-Ad-cbb-:1:1:1:00:0:0:0:0:10

X:Player 1 O:Player 2
Score is X:0 O:0. Unlimited Game
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X X | | X O O O O |
| X X | | O O O O |
| | | O O |
| | | O |
| | | |
| |BAR| |
| | | |
| | | |
| | | | +---+
| O X | | X X X X | | 2 |
| O O X | | X X X X O | +---+
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 131 O: 102 X-O: 0-0
Cube: 2, X own cube
X on roll, cube action

I was surprised that XG thought this position was way too good to
double. O is not on the bar, X is still about 30 pips down, his
five-prime is broken, and O's board, while partially crunched,
is still strong enough to cause X grief if X is hit. But a closer
look reveals that X doesn't have any really bad rolls. His worst
rolls are 62 and 41, which give O an indirect shot at the 8pt blot
that he'll have to create. Even if O hits loose on her 6pt, X
will remain a favorite.

I did spot check a few variations to look for anomalies. If X
rolls 41 and plays 8/3, and then O rolls 54 and hits, then is X
supposed to double from the bar? 3-ply, 4-ply, XGR, and even XGR+
all say no, but a rollout says yes. But I doubt that such anomalies
swing the TG verdict.

Analyzed in Rollout
No redouble
Player Winning Chances: 80.27% (G:28.69% B:1.14%)
Opponent Winning Chances: 19.73% (G:4.33% B:0.06%)
Redouble/Take
Player Winning Chances: 81.52% (G:27.81% B:1.12%)
Opponent Winning Chances: 18.48% (G:4.06% B:0.06%)

Cubeful Equities:
No redouble: +1.074
Redouble/Take: +1.641 (+0.567)
Redouble/Pass: +1.000 (-0.074)

Best Cube action: Too good to redouble / Pass
Percentage of wrong take needed to make the double decision right: 11.6%

Rollout:
1296 Games rolled with Variance Reduction.
Dice Seed: 271828
Moves: 3-ply, cube decisions: XG Roller
Confidence No Double: ± 0.008 (+1.066..+1.083)
Confidence Double: ± 0.017 (+1.624..+1.658)

eXtreme Gammon Version: 2.19.207.pre-release

---
Tim Chow

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)