BGonline.org Forums

Rollout: Ace-point anchor and blot vs. 4-prime: How bad is it?

Posted By: Timothy Chow
Date: Sunday, 13 June 2010, at 5:00 a.m.

In Response To: Ace-point anchor and blot vs. 4-prime: How bad is it? (Timothy Chow)

I thought this was an easy take, and the rollout indicates that it is a take but much closer than I thought. Move Blue's inner point deeper, to the 2 point, and it becomes a clear drop (see below). I would have taken in either position. I think I was misled by remembering positions that were similar but where Blue had only one checker behind the prime, and reasonable chances of escaping with a winning race.

---

gnubg	145
tchow	151
Position ID: TM/gATCw28gDIA Match ID: MAEAAMAAMAAA

Cube decision
Rollout cubeless equity		+0.562
Cubeful equities:
1.	Double, take	+0.934
2.	Double, pass	+1.000	+0.066
3.	No double	+0.848	-0.086
Proper cube action:		Double, take
Rollout details
Win W g W bg Lose L g L bg Cubeless Cubeful Centered 1-cube 0.721 0.174 0.011 - 0.279 0.065 0.001 +0.562 +0.848 Standard error 0.001 0.002 0.001 - 0.001 0.001 0.000 0.003 0.009 Player tchow owns 2-cube 0.724 0.178 0.012 - 0.276 0.062 0.002 +1.148 +0.934 Standard error 0.002 0.003 0.001 - 0.002 0.001 0.000 0.010 0.014
Full cubeful rollout with var.redn.
1296 games, Mersenne Twister dice gen. with seed 893316779 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]

---

gnubg	145
tchow	149
Position ID: Rs/gATCw28gDIA Match ID: MAEAAMAAMAAA

Cube decision
Rollout cubeless equity		+0.603
Cubeful equities:
1.	Double, pass	+1.000
2.	Double, take	+1.050	+0.050
3.	No double	+0.895	-0.105
Proper cube action:		Double, pass
Rollout details
Win W g W bg Lose L g L bg Cubeless Cubeful Centered 1-cube 0.736 0.182 0.010 - 0.264 0.061 0.001 +0.603 +0.895 Standard error 0.001 0.002 0.001 - 0.001 0.001 0.000 0.003 0.011 Player tchow owns 2-cube 0.741 0.181 0.011 - 0.259 0.056 0.002 +1.233 +1.050 Standard error 0.002 0.002 0.001 - 0.002 0.001 0.000 0.009 0.015
Full cubeful rollout with var.redn.
1296 games, Mersenne Twister dice gen. with seed 891429787 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

• Ace-point anchor and blot vs. 4-prime: How bad is it?
  Timothy Chow -- Saturday, 12 June 2010, at 1:41 a.m.
  • Ace-point anchor and blot vs. 4-prime: How bad is it?
    Casper van der Tak -- Saturday, 12 June 2010, at 5:44 a.m.
  • Ace-point anchor and blot vs. 4-prime: How bad is it?
    Grigorij Perel -- Saturday, 12 June 2010, at 7:46 a.m.
  • Rollout: Ace-point anchor and blot vs. 4-prime: How bad is it?
    Timothy Chow -- Sunday, 13 June 2010, at 5:00 a.m.
    • Rollout: Ace-point anchor and blot vs. 4-prime: How bad is it?
      Alexandre Le Siege -- Monday, 14 June 2010, at 4:22 a.m.
      • Rollout: Ace-point anchor and blot vs. 4-prime: How bad is it?
        Casper van der Tak -- Monday, 14 June 2010, at 6:55 a.m.
        • Rollout: Ace-point anchor and blot vs. 4-prime: How bad is it?
          Alexandre Le Siege -- Monday, 14 June 2010, at 4:52 p.m.
          • Rollout: Ace-point anchor and blot vs. 4-prime: How bad is it?
            Casper van der Tak -- Tuesday, 15 June 2010, at 12:54 a.m.
        • Rollout: Ace-point anchor and blot vs. 4-prime: How bad is it?
          Timothy Chow -- Monday, 14 June 2010, at 11:38 p.m.
          • Rollout: Ace-point anchor and blot vs. 4-prime: How bad is it?
            Casper van der Tak -- Tuesday, 15 June 2010, at 12:55 a.m.
  • Ace-point anchor and blot vs. 4-prime: How bad is it?
    Bob Koca -- Sunday, 13 June 2010, at 6:57 a.m.
    • Ace-point anchor and blot vs. 4-prime: How bad is it?
      Timothy Chow -- Sunday, 13 June 2010, at 5:16 p.m.
      • Ace-point anchor and blot vs. 4-prime: How bad is it?
        Bob Koca -- Sunday, 13 June 2010, at 5:33 p.m.
    • Rollout of your positionn
      Timothy Chow -- Monday, 14 June 2010, at 11:54 p.m.
      • Rollout of your positionn
        bob koca -- Tuesday, 15 June 2010, at 10:27 p.m.
        • Rollout of your positionn
          bob koca -- Wednesday, 16 June 2010, at 12:39 a.m.