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major disagreement between GnuBG 0-4 ply and rollout...or, am I doing it wrong?!

Posted By: Daniel Murphy
Date: Friday, 17 May 2013, at 8:15 a.m.

In Response To: major disagreement between GnuBG 0-4 ply and rollout...or, am I doing it wrong?! (bb766)

(1) Correct cube action is redouble/pass.

(2) Yes, you should believe the rollout. Evaluations (in this case, on 0- 1- 2- 3- and 4-ply) underestimate wins for the redoubling side. It's not unusual that rollouts, which play out a position hundreds or thousands of times, using variance reduction to get more data out of each single time, disagree with evaluations, which only look ahead none, one, two, three or four turns.

The score (after 0 games) is: White 0, Blue 0 (match to 7 points)

Move number 8: White on roll, cube decision?

White	110
Blue	60
Position ID: 7m8AANDWNgFQCA Match ID: AQHgAAAAAAAE

• White doubles

Cube decision
Rollout cubeless equity		+0.515	(Money: +0.509)
Cubeful equities:
1.	Double, pass	+1.000
2.	Double, take	+1.158	+0.158
3.	No double	+0.888	-0.112
Proper cube action:		Redouble, pass
Rollout details
Win W g W bg Lose L g L bg Cubeless Cubeful Player White owns 2-cube 0.795 0.000 0.000 - 0.205 0.076 0.004 +0.515 +0.888 Standard error 0.002 0.000 0.000 - 0.002 0.002 0.001 0.004 0.009 Player Blue owns 4-cube 0.825 0.000 0.000 - 0.175 0.075 0.011 +1.226 +1.158 Standard error 0.001 0.000 0.000 - 0.001 0.002 0.002 0.007 0.008
Full cubeful rollout with var.redn.
1090 games, Mersenne Twister dice gen. with seed 683014454 and quasi-random dice
Play: world class 2-ply cubeful prune [world class]
keep the first 0 0-ply moves and up to 8 more moves within equity 0.16
Skip pruning for 1-ply moves.
Cube: 2-ply cubeful prune [world class]

Annotation

0-ply cubeless equity +0.373 (Money: +0.378)
0.722 0.000 0.000 - 0.278 0.065 0.001
Cubeful equities:
1. No double +0.645
2. Double, pass +1.000 ( +0.355)
3. Double, take +0.636 ( -0.009)
Proper cube action: No redouble, take (2.4%)

1-ply cubeless equity +0.444 (Money: +0.449)
0.761 0.000 0.000 - 0.239 0.071 0.002
Cubeful equities:
1. Double, take +0.831
2. Double, pass +1.000 ( +0.169)
3. No double +0.672 ( -0.159)
Proper cube action: Redouble, take

2-ply cubeless equity +0.394 (Money: +0.400)
0.737 0.000 0.000 - 0.263 0.072 0.002
Cubeful equities:
1. Double, take +0.706
2. Double, pass +1.000 ( +0.294)
3. No double +0.669 ( -0.037)
Proper cube action: Redouble, take

3-ply cubeless equity +0.475 (Money: +0.481)
0.777 0.000 0.000 - 0.223 0.071 0.002
Cubeful equities:
1. Double, take +0.909
2. Double, pass +1.000 ( +0.091)
3. No double +0.755 ( -0.154)
Proper cube action: Redouble, take

4-ply cubeless equity +0.428 (Money: +0.434)
0.752 0.000 0.000 - 0.248 0.070 0.002
Cubeful equities:
1. Double, take +0.787
2. Double, pass +1.000 ( +0.213)
3. No double +0.699 ( -0.088)
Proper cube action: Redouble, take

Messages In This Thread

• major disagreement between GnuBG 0-4 ply and rollout...or, am I doing it wrong?!
  bb766 -- Friday, 17 May 2013, at 4:09 a.m.
  • How To Post a Rollout from GNU Backgammon
    Taper_Mike -- Friday, 17 May 2013, at 7:52 a.m.
    • How To Post a Rollout from GNU Backgammon
      bb766 -- Friday, 17 May 2013, at 10:00 p.m.
  • major disagreement between GnuBG 0-4 ply and rollout...or, am I doing it wrong?!
    Daniel Murphy -- Friday, 17 May 2013, at 8:15 a.m.
  • major disagreement between GnuBG 0-4 ply and rollout...or, am I doing it wrong?!
    Michael Nielsen -- Friday, 17 May 2013, at 8:40 a.m.
  • major disagreement between GnuBG 0-4 ply and rollout...or, am I doing it wrong?!
    Timothy Chow -- Friday, 17 May 2013, at 11:58 p.m.
    • major disagreement between GnuBG 0-4 ply and rollout...or, am I doing it wrong?!
      Taper_Mike -- Sunday, 19 May 2013, at 12:19 a.m.
      • Bots, cubes, and equities
        Timothy Chow -- Sunday, 19 May 2013, at 2:27 a.m.
        • Bots, cubes, and equities
          Taper_Mike -- Sunday, 19 May 2013, at 9:38 p.m.