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Attack or Anchor? -- Rollout + Variants

Posted By: Igor
Date: Saturday, 20 July 2013, at 4:02 p.m.

In Response To: Attack or Anchor? (Igor)

I also hit OtB for all the same reasons spelled out below and was surprised to see that XG suggests making an anchor.

White is Player 2 score: 0 pip: 157 Unlimited Game Jacoby Beaver pip: 153 score: 0 Blue is Player 1 XGID=----a-EbCB--dC---bAd-b--A-:0:0:1:42:0:0:3:0:10 Blue to play 42

1. Rollout1 24/18 eq: +0.165 Player: Opponent: 54.56% (G:9.58% B:0.31%) 45.44% (G:8.33% B:0.30%) Conf.: ± 0.007 (+0.158...+0.171) - [99.8%] Duration: 1 hour 05 minutes 2. Rollout1 8/4* 6/4 eq: +0.150 (-0.014) Player: Opponent: 53.68% (G:14.51% B:0.58%) 46.32% (G:11.67% B:0.43%) Conf.: ± 0.008 (+0.142...+0.158) - [0.2%] Duration: 1 hour 05 minutes 1 5184 Games rolled with Variance Reduction. Dice Seed: 63578012 Moves: 3-ply, cube decisions: XG Roller

eXtreme Gammon Version: 2.10

So, I started looking at variants trying to understand what features of the OP incline us to anchor. First off, my favorite distribution of spares thing. It surely should tip the scales towards the attacking play:

White is Player 2 score: 0 pip: 157 Unlimited Game Jacoby Beaver pip: 148 score: 0 Blue is Player 1 XGID=----a-EbDB--dB---bAd-b--A-:0:0:1:42:0:0:3:0:10 Blue to play 42

1. Rollout1 24/18 eq: +0.243 Player: Opponent: 56.75% (G:9.64% B:0.27%) 43.25% (G:8.01% B:0.27%) Conf.: ± 0.013 (+0.230...+0.256) - [100.0%] Duration: 15 minutes 17 seconds 2. Rollout1 8/4* 6/4 eq: +0.203 (-0.040) Player: Opponent: 54.88% (G:16.31% B:0.68%) 45.12% (G:11.40% B:0.41%) Conf.: ± 0.015 (+0.189...+0.218) - [0.0%] Duration: 15 minutes 17 seconds 1 1296 Games rolled with Variance Reduction. Dice Seed: 95792454 Moves: 3-ply, cube decisions: XG Roller

eXtreme Gammon Version: 2.10

Nope. OK, let's move white's home board point around. Let's start with 5pt -- I expect anchoring come out on top now since otherwise we'll be making a comparatively inferior home board point.

White is Player 2 score: 0 pip: 159 Unlimited Game Jacoby Beaver pip: 153 score: 0 Blue is Player 1 XGID=----a-EbCB--dC---bAdb---A-:0:0:1:42:0:0:3:0:10 Blue to play 42

1. Rollout1 24/18 eq: +0.169 Player: Opponent: 54.79% (G:9.31% B:0.26%) 45.21% (G:8.63% B:0.29%) Conf.: ± 0.014 (+0.155...+0.183) - [100.0%] Duration: 16 minutes 12 seconds 2. Rollout1 8/4* 6/4 eq: +0.094 (-0.075) Player: Opponent: 52.43% (G:13.93% B:0.50%) 47.57% (G:11.94% B:0.41%) Conf.: ± 0.014 (+0.079...+0.108) - [0.0%] Duration: 16 minutes 58 seconds 1 1296 Games rolled with Variance Reduction. Dice Seed: 42515511 Moves: 3-ply, cube decisions: XG Roller

eXtreme Gammon Version: 2.10

Aha! That's probably it. Now, let's move white's home board point to the 2pt. Now we are making a superior point and attacking should be the right move.

White is Player 2 score: 0 pip: 153 Unlimited Game Jacoby Beaver pip: 153 score: 0 Blue is Player 1 XGID=----a-EbCB--dC---bAd---bA-:0:0:1:42:0:0:3:0:10 Blue to play 42

1. Rollout1 8/4* 6/4 eq: +0.290 Player: Opponent: 57.19% (G:16.30% B:0.58%) 42.81% (G:10.65% B:0.40%) Conf.: ± 0.015 (+0.275...+0.305) - [100.0%] Duration: 15 minutes 28 seconds 2. Rollout1 24/18 eq: +0.178 (-0.112) Player: Opponent: 54.86% (G:9.63% B:0.36%) 45.14% (G:7.36% B:0.24%) Conf.: ± 0.011 (+0.167...+0.189) - [0.0%] Duration: 15 minutes 57 seconds 1 1296 Games rolled with Variance Reduction. Dice Seed: 95792454 Moves: 3-ply, cube decisions: XG Roller

eXtreme Gammon Version: 2.10

Yep! Well, that's probably what the idea is. Move the point to the 3pt:

White is Player 2 score: 0 pip: 155 Unlimited Game Jacoby Beaver pip: 153 score: 0 Blue is Player 1 XGID=----a-EbCB--dC---bAd--b-A-:0:0:1:42:0:0:3:0:10 Blue to play 42

1. Rollout1 8/4* 6/4 eq: +0.207 Player: Opponent: 55.21% (G:15.51% B:0.59%) 44.79% (G:11.41% B:0.44%) Conf.: ± 0.014 (+0.193...+0.221) - [100.0%] Duration: 15 minutes 52 seconds 2. Rollout1 24/18 eq: +0.148 (-0.059) Player: Opponent: 54.12% (G:9.36% B:0.36%) 45.88% (G:8.21% B:0.29%) Conf.: ± 0.013 (+0.135...+0.160) - [0.0%] Duration: 15 minutes 42 seconds 1 1296 Games rolled with Variance Reduction. Dice Seed: 95792454 Moves: 3-ply, cube decisions: XG Roller

eXtreme Gammon Version: 2.10

Did we figure it out? I hope so...

Messages In This Thread

• Attack or Anchor?
  Igor -- Thursday, 18 July 2013, at 3:18 p.m.
  • Attack or Anchor?
    John O'Hagan -- Thursday, 18 July 2013, at 3:36 p.m.
    • Attack or Anchor?
      Taper_Mike -- Thursday, 18 July 2013, at 4:07 p.m.
    • Attack or Anchor?
      Dmitriy Obukhov -- Thursday, 18 July 2013, at 4:43 p.m.
  • Attack or Anchor?
    onur alan -- Thursday, 18 July 2013, at 3:52 p.m.
  • Attack or Anchor?
    Keene -- Thursday, 18 July 2013, at 3:55 p.m.
  • Attack or Anchor?
    ah_clem -- Thursday, 18 July 2013, at 7:01 p.m.
  • Attack or Anchor?
    Terrapin -- Friday, 19 July 2013, at 12:51 p.m.
  • Attack or Anchor?
    mandm1951 -- Friday, 19 July 2013, at 2:05 p.m.
  • Attack or Anchor? -- Rollout + Variants
    Igor -- Saturday, 20 July 2013, at 4:02 p.m.
    • Attack or Anchor? -- Rollout + Variants
      Terrapin -- Tuesday, 23 July 2013, at 10:28 a.m.
      • Attack or Anchor? -- Rollout + Variants
        Igor -- Tuesday, 23 July 2013, at 4:55 p.m.