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OTB and Rollout

Posted By: Alfred Mamlet
Date: Thursday, 14 January 2010, at 2:51 a.m.

In Response To: Double action in 2-4-5 backgame (Alfred Mamlet)

This position arose in a side event in NY. I doubled, figuring I was likely to cover my 5 point, reading my opponent as possibly passing, and thinking I could lose my market. My opponent passed.

I was far from sure my double was theoretically correct.

XG struggles with this too.

The 5-ply evaluation is +.334 and ND

	is Player 2 score: 5 pip: 92 7 point match pip: 197 score: 1 is Player 1
XGID=----BABAAA------bbbgCB-Bb-:0:0:1:00:1:5:0:7:10
on roll, cube action?

Analyzed in 5 ply
Player Winning Chances:	56.73% (G: 9.63% B: 0.37%)
Opponent Winning Chances:	43.27% (G: 21.93% B: 0.92%)
Cubeless Equities
No Double:	-0.096
Double:	+0.300
Cubeful Equities
No Double:	+0.334
Double/Take:	+0.300 (-0.035)
Double/Drop:	+1.000 (+0.666)
Best Cube action: No Double / Take

eXtreme Gammon Version: 1.11, MET: GnuBG 11 point

The 5K rollout increased the evaluation by .148 to .582 but the double is still TCTC. I will extend the rollout to 10k but not sure that will be enough to get a clear answer on the double.

	is Player 2 score: 5 pip: 92 7 point match pip: 197 score: 1 is Player 1
XGID=----BABAAA------bbbgCB-Bb-:0:0:1:00:1:5:0:7:10
on roll, cube action?

Analyzed in Rollout
No Double
Player Winning Chances:	60.00% (G: 14.03% B: 0.80%)
Opponent Winning Chances:	40.00% (G: 25.94% B: 4.03%)
Double/Take
Player Winning Chances:	59.79% (G: 14.76% B: 0.88%)
Opponent Winning Chances:	40.21% (G: 27.86% B: 3.47%)
Cubeless Equities
No Double:	-0.043
Double:	+0.603
Cubeful Equities
No Double:	+0.578 (-0.004)
Double/Take:	+0.582
Double/Drop:	+1.000 (+0.418)
Best Cube action: Double / Take
Rollout details
5184 Games rolled with Variance Reduction. Moves and cube decisions: 3 ply
Confidence No Double:	± 0.014 (+0.563...+0.592)
Confidence Double:	± 0.016 (+0.566...+0.597)
Double Decision confidence:	64.3%
Take Decision confidence:	100.0%
Duration: 5 hours 01 minute 56 seconds

eXtreme Gammon Version: 1.11, MET: GnuBG 11 point

Messages In This Thread

• Double action in 2-4-5 backgame
  Alfred Mamlet -- Wednesday, 13 January 2010, at 2:59 a.m.
  • Double action in 2-4-5 backgame
    John O'Hagan -- Wednesday, 13 January 2010, at 3:33 a.m.
  • Double action in 2-4-5 backgame
    joe freedman -- Wednesday, 13 January 2010, at 4:05 a.m.
    • Double action in 2-4-5 backgame
      Bob Koca -- Wednesday, 13 January 2010, at 4:33 a.m.
  • Double action in 2-4-5 backgame
    Rich Munitz -- Wednesday, 13 January 2010, at 5:28 a.m.
    • Double action in 2-4-5 backgame
      Rich Munitz -- Wednesday, 13 January 2010, at 5:35 a.m.
  • Double action in 2-4-5 backgame
    Nack Ballard -- Wednesday, 13 January 2010, at 3:52 p.m.
    • Double action in 2-4-5 backgame
      neilkaz -- Wednesday, 13 January 2010, at 7:26 p.m.
      • Double action in 2-4-5 backgame
        Stick -- Wednesday, 13 January 2010, at 9:05 p.m.
    • Double action in 2-4-5 backgame
      joe freedman -- Thursday, 14 January 2010, at 5:43 a.m.
      • Double action in 2-4-5 backgame
        Nack Ballard -- Thursday, 14 January 2010, at 7:04 a.m.
  • OTB and Rollout
    Alfred Mamlet -- Thursday, 14 January 2010, at 2:51 a.m.
    • OTB and Rollout
      neilkaz -- Thursday, 14 January 2010, at 3:48 p.m.
      • OTB and Rollout
        Alfred Mamlet -- Friday, 15 January 2010, at 2:17 a.m.
        • OTB and Rollout
          Bob Koca -- Friday, 15 January 2010, at 3:49 a.m.
          • OTB and Rollout
            joe freedman -- Saturday, 16 January 2010, at 6:28 a.m.
            • OTB and Rollout
              Bob Koca -- Saturday, 16 January 2010, at 7:23 a.m.
              • OTB and Rollout
                joe freedman -- Sunday, 17 January 2010, at 4:07 a.m.