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Rollout

Posted By: Timothy Chow
Date: Wednesday, 2 December 2009, at 12:13 a.m.

In Response To: Too good to double (John O'Hagan)

The rollout agrees with you. Over the board, I played 12/6 9/7, thinking that 9/3 7/5 buried a checker and made it likely that I would have to leave an indirect shot the next turn or two as I tried to bring my back two checkers in. However, I overlooked that my opponent would hit with double-4's. It surprises me a little that a single joker roll would make that much difference, but I guess it does. For example, if I move my back checkers from the 12-point to the 11-point, then GNU 4-ply definitely prefers 11/5 9/7. (Of course the comparison is complicated by the fact that 11/5 creates another builder for the 4-point, which 12/6 doesn't.)

gnubg	106
tchow	80
Position ID: eHczAEDb7BIDAA Match ID: UQkLAJAAAAAA

#		Ply	Move	Equity
•	1	R	9/3 7/5	+1.013
			0.892 0.083 0.001 - 0.108 0.004 0.000 +0.864 +1.013 0.001 0.001 0.000 - 0.001 0.000 0.000 0.002 0.002
			Full cubeful rollout with var.redn.
			1296 games, Mersenne Twister dice gen. with seed 841321761 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]
	2	R	12/6 9/7	+0.986 ( -0.027)
			0.908 0.084 0.000 - 0.092 0.002 0.000 +0.899 +0.986 0.001 0.001 0.002 - 0.001 0.000 0.000 0.002 0.002
			Full cubeful rollout with var.redn.
			1296 games, Mersenne Twister dice gen. with seed 841321761 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

• Too good to double
  Timothy Chow -- Tuesday, 1 December 2009, at 1:30 a.m.
  • Too good to double
    John O'Hagan -- Tuesday, 1 December 2009, at 5:17 a.m.
    • Too good to double
      John O'Hagan -- Tuesday, 1 December 2009, at 5:22 a.m.
    • Rollout
      Timothy Chow -- Wednesday, 2 December 2009, at 12:13 a.m.
      • Rollout
        Matt Cohn-Geier -- Wednesday, 2 December 2009, at 12:47 a.m.
        • Rollout
          Matt Cohn-Geier -- Wednesday, 2 December 2009, at 12:50 a.m.
  • GG?
    Chuck Bower -- Thursday, 3 December 2009, at 5:42 p.m.