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Rollout, and a related question

Posted By: Timothy Chow
Date: Thursday, 12 November 2009, at 9:39 p.m.

In Response To: Bearing in against contact (Timothy Chow)

The correct play here is the obvious one of making the 5-point. I posted the position, however, because there is a very similar position (see below) where one might assume that making the 5-point is also the right play, but where the rollout suggests otherwise. (In fact, I was tempted to post the position below instead of the position I actually posted, but the position I actually posted was the one that actually came up. Plus, it's good to post some problems where the QF answer isn't the right one, just to keep us honest!) I'm surprised that the two positions roll out so differently. Would those of you who made the 5-point in my original position have also made the 5-point here?

gnubg	78
tchow	54
Position ID: 7e4GAEBvmxsAAA Match ID: QYkIABAAMAAA

#		Ply	Move	Equity
•	1	R	6/3	+0.754
			0.889 0.005 0.000 - 0.111 0.001 0.000 +0.782 +0.754 0.000 0.000 0.000 - 0.000 0.000 0.000 0.000 0.001
			Full cubeful rollout with var.redn.
			5184 games, Mersenne Twister dice gen. with seed 869612543 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	7/4	+0.737 ( -0.017)
			0.881 0.008 0.000 - 0.119 0.001 0.000 +0.769 +0.737 0.000 0.000 0.000 - 0.000 0.000 0.000 0.000 0.001
			Full cubeful rollout with var.redn.
			5184 games, Mersenne Twister dice gen. with seed 869612543 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]
	3	R	7/5 6/5	+0.734 ( -0.020)
			0.877 0.015 0.000 - 0.123 0.000 0.000 +0.768 +0.734 0.000 0.000 0.000 - 0.000 0.000 0.000 0.001 0.001
			Full cubeful rollout with var.redn.
			5184 games, Mersenne Twister dice gen. with seed 869612543 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]

For completeness, here's the rollout of the original position.

gnubg	78
tchow	56
Position ID: 7e4GAEBvmzMAAA Match ID: QYkFABAAMAAA

#		Ply	Move	Equity
•	1	R	8/5 6/5	+0.793
			0.903 0.014 0.000 - 0.097 0.000 0.000 +0.821 +0.793 0.000 0.000 0.000 - 0.000 0.000 0.000 0.001 0.001
			Full cubeful rollout with var.redn.
			5184 games, Mersenne Twister dice gen. with seed 869832439 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	8/4	+0.735 ( -0.058)
			0.879 0.009 0.000 - 0.121 0.001 0.000 +0.766 +0.735 0.000 0.000 0.000 - 0.000 0.000 0.000 0.000 0.001
			Full cubeful rollout with var.redn.
			5184 games, Mersenne Twister dice gen. with seed 869832439 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]
	3	R	6/2	+0.672 ( -0.122)
			0.852 0.005 0.000 - 0.148 0.002 0.000 +0.706 +0.672 0.000 0.000 0.000 - 0.000 0.000 0.000 0.001 0.001
			Full cubeful rollout with var.redn.
			5184 games, Mersenne Twister dice gen. with seed 869832439 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

• Bearing in against contact
  Timothy Chow -- Thursday, 12 November 2009, at 4:20 a.m.
  • Bearing in against contact
    lenny -- Thursday, 12 November 2009, at 7:07 a.m.
  • Bearing in against contact
    Chuck Bower -- Thursday, 12 November 2009, at 5:33 p.m.
    • Bearing in against contact
      neilkaz -- Thursday, 12 November 2009, at 5:53 p.m.
  • Bearing in against contact
    Keene -- Thursday, 12 November 2009, at 8:14 p.m.
  • Rollout, and a related question
    Timothy Chow -- Thursday, 12 November 2009, at 9:39 p.m.
    • Rollout, and a related question
      Sam Pottle -- Thursday, 12 November 2009, at 10:08 p.m.
      • Rollout, and a related question
        Chuck Bower -- Thursday, 12 November 2009, at 11:33 p.m.