Robertie Position 365

GNU agrees with Robertie here, but as with Position 362, I am posting the rollout anyway because I think the position is sufficiently interesting. Note that backgames are not GNU’s strength; however, eXtreme Gammon rollouts by neilkaz and by KenB come to the same qualitative conclusion (though XG and GNU assign quite different absolute equities to the given position, and XG thinks the decision is closer than GNU thinks).

Alert: wrong double ( -0.050)! [doubtful]

Cube decision

Rollout cubeless equity

+0.471

Cubeful equities:

No double

+0.611

Double, pass

+1.000

+0.389

Double, take

+0.561

-0.050

Proper cube action:

No double, take (11.3%)

Rollout details

	Win	W g	W bg		Lose	L g	L bg	Cubeless	Cubeful
Centered 1-cube	0.611	0.295	0.018	-	0.389	0.063	0.002	+0.471	+0.611
Standard error	0.001	0.001	0.001	-	0.001	0.001	0.000	0.003	0.007
Player gnubg owns 2-cube	0.612	0.288	0.016	-	0.388	0.063	0.002	+0.925	+0.561
Standard error	0.001	0.001	0.001	-	0.001	0.001	0.000	0.006	0.008

Full cubeful rollout with var.redn.

15552 games, Mersenne Twister dice gen. with seed 840277921 and quasi-random dice

Play: supremo 2-ply cubeful prune [world class]

keep the first 0 0-ply moves and up to 16 more moves within equity 0.32

Skip pruning for 1-ply moves.

Cube: 2-ply cubeful prune [world class]