3-away/7-away cube action

[Timothy Chow]

XGID=-ABBBBBa-----Ba----cBb--h-:0:0:1:00:4:0:0:7:10

Score is X:4 O:0 7 pt.(s) match.
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X O | | O X O O |
| X | | O X O O |
| | | O O |
| | | O |
| | | 8 |
| |BAR| |
| | | |
| | | |
| | | |
| | | X X X X X |
| O | | X X X X X X |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 107 O: 63 X-O: 4-0/7
Cube: 1
X on roll, cube action

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Tim Chow

[Timothy Chow]

Stick's rule is not to double at 3-away/many-away in gammonish
positions. The exception that I have learned is that if the 3-away
player *loses* very few gammons, then it can still be a double if
it's close to pass. Here, X indeed loses very few gammons, but it's
not all that close to being a pass. Nevertheless, XG insists on
doubling. So, is this another class of exceptions? It's a rather
unusual position so I hesitate to draw a general conclusion.

Analyzed in Rollout
No double
Player Winning Chances: 74.31% (G:26.06% B:0.96%)
Opponent Winning Chances: 25.69% (G:2.66% B:0.01%)
Double/Take
Player Winning Chances: 74.70% (G:25.23% B:1.44%)
Opponent Winning Chances: 25.30% (G:2.59% B:0.15%)

Cubeful Equities:
No double: +0.701 (-0.190)
Double/Take: +0.891
Double/Pass: +1.000 (+0.109)

Best Cube action: Double / Take

Rollout:
1296 Games rolled with Variance Reduction.
Dice Seed: 271828
Moves: 3-ply, cube decisions: XG Roller
Confidence No Double: ± 0.009 (+0.692..+0.710)
Confidence Double: ± 0.013 (+0.878..+0.905)

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

---
Tim Chow

[Stick Rice]

The rule is for 3a 7a or greater. Given that that's where we (I) decided to begin the rule it should be intuitive that there will be more exceptions at 3a 7a than 3a 8a or 3a 9a etc...It's not really surprising to see an exception and like you said, you can narrow down when they happen and incorporate that into your game. That's what over reaching adages are for, to give the end user a generalized building block that works the vast majority of the time. Hopefully they incorporate it into their game and realize when the maxim falls short, figure out the why, and add that addendum mentally to your banked knowledge. Constantly building on that you can end up with some cutting axioms. Or, the short version, make the dmp play ;)

Stick