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Rollout: Double from the bar?

Posted By: Timothy Chow
Date: Sunday, 30 May 2010, at 5:18 a.m.

In Response To: Double from the bar? (Timothy Chow)

I was (and am) surprised to find that GNU thinks it's a huge error not to double in the first position. The second position is nearly a pass, so I guess that explains why Blue has market losers. I guess that part of what's going on is that White has so many checkers back and is (therefore) so far behind in the race. Move one of White's checkers from White's 21 point to White's 3 point and I think it's a borderline double at best. Still, I would have thought that White's strong forward position would count for more than it apparently does.

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tchow on roll; cube action?

gnubg	152
tchow	119
Position ID: NtsAwAvDbgcDQA Match ID: cAkAAAAAAAAA

Alert: missed double ( -0.100)! [bad]

Cube decision
Rollout cubeless equity		+0.525
Cubeful equities:
1.	Double, take	+0.832
2.	Double, pass	+1.000	+0.168
3.	No double	+0.732	-0.100
Proper cube action:		Double, take
Rollout details
Win W g W bg Lose L g L bg Cubeless Cubeful Centered 1-cube 0.686 0.224 0.005 - 0.314 0.073 0.002 +0.525 +0.732 Standard error 0.001 0.002 0.000 - 0.001 0.001 0.000 0.003 0.008 Player gnubg owns 2-cube 0.692 0.227 0.004 - 0.308 0.069 0.002 +1.089 +0.832 Standard error 0.002 0.002 0.000 - 0.002 0.001 0.000 0.008 0.012
Full cubeful rollout with var.redn.
1296 games, Mersenne Twister dice gen. with seed 853376975 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]

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tchow on roll; cube action?

gnubg	142
tchow	113
Position ID: NtsQgAvD3gYDBA Match ID: cAkAAAAAAAAA

Alert: missed double ( -0.177)! [very bad]

Cube decision
Rollout cubeless equity		+0.563
Cubeful equities:
1.	Double, take	+0.963
2.	Double, pass	+1.000	+0.037
3.	No double	+0.785	-0.177
Proper cube action:		Double, take
Rollout details
Win W g W bg Lose L g L bg Cubeless Cubeful Centered 1-cube 0.710 0.199 0.004 - 0.290 0.059 0.002 +0.563 +0.785 Standard error 0.001 0.001 0.000 - 0.001 0.001 0.000 0.002 0.005 Player gnubg owns 2-cube 0.717 0.208 0.003 - 0.283 0.056 0.002 +1.177 +0.963 Standard error 0.001 0.002 0.000 - 0.001 0.001 0.000 0.007 0.009
Full cubeful rollout with var.redn.
1296 games, Mersenne Twister dice gen. with seed 852881963 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]

Messages In This Thread

• Double from the bar?
  Timothy Chow -- Saturday, 29 May 2010, at 2:58 a.m.
  • Double from the bar?
    garyo -- Saturday, 29 May 2010, at 7:35 a.m.
  • Rollout: Double from the bar?
    Timothy Chow -- Sunday, 30 May 2010, at 5:18 a.m.