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OTB and rollout

Posted By: Timothy Chow
Date: Saturday, 25 June 2011, at 5:04 p.m.

In Response To: A decision you're unlikely to face when playing a bot (Timothy Chow)

I had already cashed earlier in the game so I was observing passively. The team captain played 13/5 at first, but then after some discussion with the team (our chouette is a consulting chouette), switched to 13/10 13/8. The rollout indicates that this is a whopper. My explanation is that though 13/10 13/8 leaves fewer shots, it is much more painful if White, in addition to hitting, escapes a back checker and potentially picks up a second blot. Indeed, the box did in fact hit immediately and subsequently cruise to a win.

6/3 6/1 is unnecessarily cautious given White's damaged board.

However, the variant position indicates that we should be a little cautious about jumping to conclusions. Giving White a strong board, not too surprisingly, turns 6/3 6/1 into a candidate, but more surprisingly to me at least, also apparently turns 13/5 into the whopper. We could explain this by arguing that in the variant, getting hit after either play is so bad that one should minimize shots. That's plausible, but just how bad is it? Is it a cash? XG finds the cube decision after 13/5, hit/dance to be a difficult question, with 3-ply, 4-ply, and XGR+ having different opinions. Therefore I'm not sure how much to trust the rollout figures.

		White is Player 2 score: 0 pip: 113 Money session Jacoby Beaver pip: 81 score: 0 Blue is Player 1
XGID=-BbCBBBB----bB----c--bbbb-:1:-1:1:53:0:0:3:0:10
Blue to play 53

1.	Rollout1	13/5	eq: +0.732
	Player: Opponent: 84.01% (G:11.23% B:0.24%) 15.99% (G:0.65% B:0.02%) Conf: ± 0.006 (+0.726...+0.738) Duration: 24 minutes 41 seconds
2.	Rollout1	13/10 13/8	eq: +0.593 (-0.139)
	Player: Opponent: 78.69% (G:11.90% B:0.24%) 21.31% (G:2.02% B:0.04%) Conf: ± 0.007 (+0.586...+0.600) Duration: 24 minutes 28 seconds
1 1296 Games rolled with Variance Reduction. Dice Seed: 2 Moves and cube decisions: 3 ply

eXtreme Gammon Version: 1.21

Rollout of variant:

		White is Player 2 score: 0 pip: 129 Money session Jacoby Beaver pip: 81 score: 0 Blue is Player 1
XGID=-BbCBBBB----bB----cbbbb---:1:-1:1:53:0:0:3:0:10
Blue to play 53

1.	Rollout1	13/10 13/8	eq: +0.254
	Player: Opponent: 65.82% (G:10.69% B:0.30%) 34.18% (G:5.85% B:0.31%) Conf: ± 0.006 (+0.248...+0.260) Duration: 3 hours 12 minutes
2.	Rollout1	6/3 6/1	eq: +0.236 (-0.018)
	Player: Opponent: 65.55% (G:8.39% B:0.12%) 34.45% (G:4.68% B:0.18%) Conf: ± 0.007 (+0.229...+0.243) Duration: 3 hours 06 minutes
3.	Rollout1	13/5	eq: +0.154 (-0.100)
	Player: Opponent: 63.04% (G:9.39% B:0.18%) 36.96% (G:5.46% B:0.19%) Conf: ± 0.010 (+0.144...+0.164) Duration: 2 hours 53 minutes
1 1296 Games rolled with Variance Reduction. Dice Seed: 2 First 4 moves and cube decisions: 4 ply Remaining moves and cube decisions: 3 ply

eXtreme Gammon Version: 1.21

Messages In This Thread

• A decision you're unlikely to face when playing a bot
  Timothy Chow -- Friday, 24 June 2011, at 3:32 p.m.
  • A decision you're unlikely to face when playing a bot
    BenF -- Friday, 24 June 2011, at 3:48 p.m.
  • A decision you're unlikely to face when playing a bot
    Fender -- Friday, 24 June 2011, at 3:48 p.m.
  • A decision you're unlikely to face when playing a bot
    Kevin Whyte -- Friday, 24 June 2011, at 4:18 p.m.
    • A decision you're unlikely to face when playing a bot
      BenF -- Friday, 24 June 2011, at 4:38 p.m.
      • A decision you're unlikely to face when playing a bot
        Kevin Whyte -- Friday, 24 June 2011, at 5:48 p.m.
  • A decision you're unlikely to face when playing a bot
    neilkaz -- Friday, 24 June 2011, at 5:24 p.m.
    • A decision you're unlikely to face when playing a bot
      Steve Mellen -- Friday, 24 June 2011, at 7:43 p.m.
  • Variant: Same play or different play?
    Timothy Chow -- Friday, 24 June 2011, at 9:15 p.m.
  • A decision you're unlikely to face when playing a bot
    ah_clem -- Saturday, 25 June 2011, at 12:46 p.m.
  • OTB and rollout
    Timothy Chow -- Saturday, 25 June 2011, at 5:04 p.m.