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CA 5prime vs 1 back ROs

Posted By: Daniel Murphy
Date: Thursday, 18 August 2011, at 10:03 p.m.

In Response To: Cube action with 5 prime vs 1 back (Daniel Murphy)

Here are Gnubg rollouts and even-ply evaluations for the three positions -- my original and Stick's two alternates -- where Blue has a checker on the bar. To keep a multi-position post shorter, I've abbreviated the rollout output to show the D/T data only, since they are clearly not "No Doubles." All the Gnubg evaluations are wrong.

Bring on the XG rollouts, please! I'm looking for more wins and fewer gammon losses in all three positions.

Money game. Blue on roll.

White	57
Blue	158
Position ID: 7+4BAAhw2wZgQQ Match ID: UQkAAAAAAAAE

Rollout	W	W(G)	W(BG)	L(G)	L(BG)	CL	CF	95% CI	Cube Action
2-ply WC 1296	0.7767	0.0556	0.0014	0.1250	0.0004	+0.9700	+0.9051	+-0.0199	D/T

Annotation

Cube analysis
2-ply cubeless equity +0.2846
0.7015 0.0471 0.0002 - 0.2985 0.1652 0.0006
Cubeful equities:
1. No double +0.5453
2. Double, pass +1.0000 ( +0.4547)
3. Double, take +0.3733 ( -0.1720)
Proper cube action: No redouble, take (27.4%)

Cube analysis
4-ply cubeless equity +0.2997
0.7083 0.0444 0.0002 - 0.2917 0.1610 0.0006
Cubeful equities:
1. No double +0.5947
2. Double, pass +1.0000 ( +0.4053)
3. Double, take +0.4132 ( -0.1815)
Proper cube action: No redouble, take (30.9%)

White	58
Blue	148
Position ID: 7+4BABDYbQNgQQ Match ID: UQkAAAAAAAAE

Rollout	W	W(G)	W(BG)	L(G)	L(BG)	CL	CF	95% CI	Cube Action
2-ply WC 1296	0.7853	0.0555	0.0013	>0.1026	0.0003	+1.0490	+0.9887	+-0.0160	D/T

Annotation

Cube analysis
2-ply cubeless equity +0.3835
0.7300 0.0462 0.0001 - 0.2700 0.1223 0.0005
Cubeful equities:
1. No double +0.6824
2. Double, pass +1.0000 ( +0.3176)
3. Double, take +0.5884 ( -0.0941)
Proper cube action: No redouble, take (22.9%)

Cube analysis
4-ply cubeless equity +0.3919
0.7341 0.0450 0.0001 - 0.2659 0.1211 0.0005
Cubeful equities:
1. No double +0.7128
2. Double, pass +1.0000 ( +0.2872)
3. Double, take +0.6177 ( -0.0951)
Proper cube action: No redouble, take (24.9%)

White	59
Blue	138
Position ID: 7+4BACBstwFgQQ Match ID: UQkAAAAAAAAE

Rollout	W	W(G)	W(BG)	L(G)	L(BG)	CL	CF	95% CI	Cube Action
2-ply WC 1296	0.7937	0.0521	0.0012	0.0864	0.0004	+1.1077	+1.0412	+-0.0129	D/P

Annotation

Cube analysis
2-ply cubeless equity +0.4538
0.7508 0.0475 0.0002 - 0.2492 0.0950 0.0004
Cubeful equities:
1. No double +0.7733
2. Double, pass +1.0000 ( +0.2267)
3. Double, take +0.7411 ( -0.0322)
Proper cube action: No redouble, take (12.4%)

Cube analysis
4-ply cubeless equity +0.4460
0.7489 0.0455 0.0002 - 0.2511 0.0971 0.0004
Cubeful equities:
1. No double +0.7681
2. Double, pass +1.0000 ( +0.2319)
3. Double, take +0.7340 ( -0.0342)
Proper cube action: No redouble, take (12.8%)

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About the other position with the checker moved from the bar to the 18 point:

Gnubg also evaluates this as No Double/Take, and, because of many bad takes, rolls it out as "too good to double" and, I think, about a 1.300 drop -- I did this rollout twice and had Gnubg crash on me trying to save it. I might do it a third time.

---

I found the first position above on Fabrice Liardet's backgammon page.

Messages In This Thread

• Cube action with 5 prime vs 1 back
  Daniel Murphy -- Wednesday, 17 August 2011, at 12:51 p.m.
  • Cube action with 5 prime vs 1 back - and 2 more
    Stick -- Wednesday, 17 August 2011, at 1:12 p.m.
  • Cube action with 5 prime vs 1 back
    Casper van der Tak -- Wednesday, 17 August 2011, at 1:45 p.m.
  • CA 5prime vs 1 back ROs
    Daniel Murphy -- Thursday, 18 August 2011, at 10:03 p.m.