BGonline.org Forums

Advanced Backgammon part 23A ROLLOUT

Posted By: Matt Cohn-Geier
Date: Monday, 4 May 2009, at 6:35 a.m.

In Response To: Advanced Backgammon part 23A (Matt Cohn-Geier)

Position 221:

This was the longest rollout to date. It took ages to get this far, even on souped up supercomputers. It's still insignificant but Robertie's play is likely at least 8th best, probably 9th or 10th. Going after the blot on the 10 point is necessary, either with 13/11 or 18/16, or both. The other deuces can be played in a variety of ways. Not extending this one anymore.

Move number 6: Blue to play 22

White	199
Blue	156
Position ID: 4Dk4AVxsG3AwIg Match ID: QQkJAAAAAAAA

• Blue moves 13/7 13/11

#		Ply	Move	Equity
	1	R	24/22 18/16(2) 13/11	+0.9866
			0.7469 0.4993 0.1380 - 0.2531 0.0198 0.0012 +1.1101 +0.9866 0.0017 0.0020 0.0022 - 0.0017 0.0003 0.0001 0.0065 0.0074
			Full cubeful rollout with var.redn.
			14205 games, Mersenne Twister dice gen. with seed 811694589 and quasi-random dice
			Play: 2-ply cubeful prune [world class]
			keep the first 0 0-ply moves and up to 12 more moves within equity 0.2
			Skip pruning for 1-ply moves.
			Cube: 2-ply cubeful prune [world class]
	2	R	18/16 13/7	+0.9820 ( -0.0046)
			0.7415 0.5038 0.1425 - 0.2585 0.0235 0.0013 +1.1044 +0.9820 0.0018 0.0020 0.0022 - 0.0018 0.0003 0.0002 0.0066 0.0083
			Full cubeful rollout with var.redn.
			14197 games, Mersenne Twister dice gen. with seed 811694589 and quasi-random dice
			Play: 2-ply cubeful prune [world class]
			keep the first 0 0-ply moves and up to 12 more moves within equity 0.2
			Skip pruning for 1-ply moves.
			Cube: 2-ply cubeful prune [world class]
	3	R	18/14(2)	+0.9806 ( -0.0060)
			0.7439 0.5019 0.1398 - 0.2561 0.0198 0.0011 +1.1088 +0.9806 0.0020 0.0023 0.0025 - 0.0020 0.0004 0.0002 0.0074 0.0083
			Full cubeful rollout with var.redn.
			11151 games, Mersenne Twister dice gen. with seed 811694589 and quasi-random dice
			Play: 2-ply cubeful prune [world class]
			keep the first 0 0-ply moves and up to 12 more moves within equity 0.2
			Skip pruning for 1-ply moves.
			Cube: 2-ply cubeful prune [world class]
•	4	R	13/7 13/11	+0.9804 ( -0.0062)
			0.7487 0.4957 0.1376 - 0.2513 0.0254 0.0013 +1.1041 +0.9804 0.0029 0.0033 0.0037 - 0.0029 0.0006 0.0002 0.0110 0.0124
			Full cubeful rollout with var.redn.
			5124 games, Mersenne Twister dice gen. with seed 810079770 and quasi-random dice
			Play: 2-ply cubeful prune [world class]
			keep the first 0 0-ply moves and up to 12 more moves within equity 0.2
			Skip pruning for 1-ply moves.
			Cube: 2-ply cubeful prune [world class]
	5	R	24/20 18/16 13/11	+0.9791 ( -0.0075)
			0.7479 0.4968 0.1345 - 0.2521 0.0239 0.0018 +1.1014 +0.9791 0.0018 0.0021 0.0023 - 0.0018 0.0003 0.0001 0.0068 0.0076
			Full cubeful rollout with var.redn.
			13166 games, Mersenne Twister dice gen. with seed 811694589 and quasi-random dice
			Play: 2-ply cubeful prune [world class]
			keep the first 0 0-ply moves and up to 12 more moves within equity 0.2
			Skip pruning for 1-ply moves.
			Cube: 2-ply cubeful prune [world class]
	6	R	18/16(2) 13/9	+0.9756 ( -0.0110)
			0.7448 0.5004 0.1346 - 0.2552 0.0199 0.0016 +1.1031 +0.9756 0.0029 0.0033 0.0035 - 0.0029 0.0004 0.0002 0.0108 0.0121
			Full cubeful rollout with var.redn.
			5561 games, Mersenne Twister dice gen. with seed 811694589 and quasi-random dice
			Play: 2-ply cubeful prune [world class]
			keep the first 0 0-ply moves and up to 12 more moves within equity 0.2
			Skip pruning for 1-ply moves.
			Cube: 2-ply cubeful prune [world class]
	7	R	18/16(2) 13/11(2)	+0.9718 ( -0.0149)
			0.7472 0.4925 0.1326 - 0.2528 0.0208 0.0013 +1.0975 +0.9718 0.0027 0.0036 0.0043 - 0.0027 0.0005 0.0001 0.0112 0.0122
			Full cubeful rollout with var.redn.
			5557 games, Mersenne Twister dice gen. with seed 811694589 and quasi-random dice
			Play: 2-ply cubeful prune [world class]
			keep the first 0 0-ply moves and up to 12 more moves within equity 0.2
			Skip pruning for 1-ply moves.
			Cube: 2-ply cubeful prune [world class]
	8	R	24/16	+0.9565 ( -0.0301)
			0.7474 0.4824 0.1237 - 0.2526 0.0209 0.0011 +1.0789 +0.9565 0.0026 0.0030 0.0030 - 0.0026 0.0005 0.0001 0.0095 0.0107
			Full cubeful rollout with var.redn.
			5531 games, Mersenne Twister dice gen. with seed 811694589 and quasi-random dice
			Play: 2-ply cubeful prune [world class]
			keep the first 0 0-ply moves and up to 12 more moves within equity 0.2
			Skip pruning for 1-ply moves.
			Cube: 2-ply cubeful prune [world class]
	9	R	24/22 13/7	+0.9485 ( -0.0382)
			0.7412 0.4870 0.1276 - 0.2588 0.0241 0.0014 +1.0715 +0.9485 0.0029 0.0035 0.0037 - 0.0029 0.0006 0.0002 0.0110 0.0124
			Full cubeful rollout with var.redn.
			4641 games, Mersenne Twister dice gen. with seed 811694589 and quasi-random dice
			Play: 2-ply cubeful prune [world class]
			keep the first 0 0-ply moves and up to 12 more moves within equity 0.2
			Skip pruning for 1-ply moves.
			Cube: 2-ply cubeful prune [world class]
	10	R	24/18 13/11	+0.9479 ( -0.0387)
			0.7460 0.4810 0.1223 - 0.2540 0.0219 0.0012 +1.0721 +0.9479 0.0030 0.0033 0.0034 - 0.0030 0.0005 0.0001 0.0107 0.0120
			Full cubeful rollout with var.redn.
			4088 games, Mersenne Twister dice gen. with seed 811694589 and quasi-random dice
			Play: 2-ply cubeful prune [world class]
			keep the first 0 0-ply moves and up to 12 more moves within equity 0.2
			Skip pruning for 1-ply moves.
			Cube: 2-ply cubeful prune [world class]

Position 222:

This one's pretty clear, making the 3 point is best for all the usual reasons. Crashing is a possibility but it's a remote one and if it does happen White would have to roll perfect to take advantage of it.

Move number 5: Blue to play 25

White	135
Blue	111
Position ID: lHsbADBmdyYAAw Match ID: QQkVAAAAAAAA

• Blue moves 8/3 5/3

#		Ply	Move	Equity
•	1	R	8/3 5/3	+0.6170
			0.7716 0.1842 0.0099 - 0.2284 0.0356 0.0008 +0.7009 +0.6170 0.0034 0.0052 0.0021 - 0.0034 0.0022 0.0006 0.0074 0.0104
			Full cubeful rollout with var.redn.
			244 games, Mersenne Twister dice gen. with seed 812421792 and quasi-random dice
			Play: 2-ply cubeful prune [world class]
			keep the first 0 0-ply moves and up to 12 more moves within equity 0.2
			Skip pruning for 1-ply moves.
			Cube: 2-ply cubeful prune [world class]
	2	R	10/3	+0.4664 ( -0.1506)
			0.7158 0.1940 0.0102 - 0.2842 0.0527 0.0023 +0.5807 +0.4664 0.0034 0.0052 0.0020 - 0.0034 0.0026 0.0005 0.0083 0.0113
			Full cubeful rollout with var.redn.
			244 games, Mersenne Twister dice gen. with seed 812421792 and quasi-random dice
			Play: 2-ply cubeful prune [world class]
			keep the first 0 0-ply moves and up to 12 more moves within equity 0.2
			Skip pruning for 1-ply moves.
			Cube: 2-ply cubeful prune [world class]
	3	R	20/13	+0.3620 ( -0.2550)
			0.6723 0.1985 0.0169 - 0.3277 0.0590 0.0026 +0.4985 +0.3620 0.0047 0.0051 0.0023 - 0.0047 0.0026 0.0005 0.0094 0.0161
			Full cubeful rollout with var.redn.
			243 games, Mersenne Twister dice gen. with seed 812421792 and quasi-random dice
			Play: 2-ply cubeful prune [world class]
			keep the first 0 0-ply moves and up to 12 more moves within equity 0.2
			Skip pruning for 1-ply moves.
			Cube: 2-ply cubeful prune [world class]

Position 223:

D/T, standard. Everyone escaped plus tactical threats and 11 in the zone is good. Blue's position isn't crushing yet, and White has counterchances.

Move number 3: Blue on roll, cube decision?

White	159
Blue	125
Position ID: jM/ggDCMz4kjAA Match ID: cAkAAAAAAAAA

• Blue doubles

Cube decision
Rollout cubeless equity		+0.5367
Cubeful equities:
1.	Double, take	+0.8691
2.	Double, pass	+1.0000	+0.1309
3.	No double	+0.7831	-0.0861
Proper cube action:		Double, take
Rollout details
Win W g W bg Lose L g L bg Cubeless Cubeful Centered 1-cube 0.6960 0.1958 0.0127 - 0.3040 0.0619 0.0019 +0.5367 +0.7831 Standard error 0.0014 0.0018 0.0009 - 0.0014 0.0010 0.0002 0.0032 0.0100 Player White owns 2-cube 0.7000 0.2008 0.0145 - 0.3000 0.0619 0.0022 +1.1026 +0.8691 Standard error 0.0011 0.0014 0.0005 - 0.0011 0.0008 0.0001 0.0052 0.0086
Full cubeful rollout with var.redn.
3222 games, Mersenne Twister dice gen. with seed 812286745 and quasi-random dice
Play: 2-ply cubeful prune [world class]
keep the first 0 0-ply moves and up to 12 more moves within equity 0.2
Skip pruning for 1-ply moves.
Cube: 2-ply cubeful prune [world class]

Messages In This Thread

• Advanced Backgammon part 23A
  Matt Cohn-Geier -- Friday, 1 May 2009, at 8:49 p.m.
  • Advanced Backgammon part 23A
    Coolrey -- Saturday, 2 May 2009, at 3:48 a.m.
  • Advanced Backgammon part 23A
    Christian Munk-Christensen -- Saturday, 2 May 2009, at 7:45 a.m.
  • Advanced Backgammon part 23A
    misja -- Saturday, 2 May 2009, at 8:24 a.m.
  • Advanced Backgammon part 23A
    Chuck Bower -- Saturday, 2 May 2009, at 12:08 p.m.
  • Robertie's picks
    Matt Cohn-Geier -- Sunday, 3 May 2009, at 4:00 a.m.
  • Advanced Backgammon part 23A
    garyo -- Sunday, 3 May 2009, at 5:35 a.m.
  • Advanced Backgammon part 23A
    garyo -- Sunday, 3 May 2009, at 5:39 a.m.
  • Advanced Backgammon part 23A ROLLOUT
    Matt Cohn-Geier -- Monday, 4 May 2009, at 6:35 a.m.