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42 to play (ROLLOUT and VARIANTS)

Posted By: Nack Ballard
Date: Saturday, 6 October 2018, at 1:13 a.m.

In Response To: 42 to play (Dmitriy Obukhov)

		White is Player 2 score: 0 pip: 125 7 point match pip: 144 score: 0 Blue is Player 1
XGID=--a-B-D-C--BbBb--bbbBb-b--:0:0:1:42:0:0:0:7:10
Original position

1.	Rollout1	8/4 6/4	eq: -0.088
	Player: Opponent: 46.10% (G:10.35% B:0.27%) 53.90% (G:8.27% B:0.30%) Conf.: ± 0.006 (-0.094...-0.082) - [100.0%] Duration: 48 minutes 29 seconds
2.	Rollout1	8/2*	eq: -0.129 (-0.040)
	Player: Opponent: 45.51% (G:12.03% B:0.35%) 54.49% (G:11.54% B:0.42%) Conf.: ± 0.006 (-0.135...-0.123) - [0.0%] Duration: 52 minutes 21 seconds
3.	Rollout2	13/11 13/9	eq: -0.171 (-0.083)
	Player: Opponent: 43.99% (G:9.28% B:0.34%) 56.01% (G:7.55% B:0.24%) Conf.: ± 0.010 (-0.182...-0.161) - [0.0%] Duration: 10 minutes 26 seconds
1 5184 Games rolled with Variance Reduction. Dice Seed: 45589264 Moves: 3-ply, cube decisions: XG Roller 2 1296 Games rolled with Variance Reduction. Dice Seed: 45589264 Moves: 3-ply, cube decisions: XG Roller

This thread appears to have been abandoned.

My rollout for Dmitriy's original position is shown above. The double-dilly play of 8/4 6/4 is cringeworthy but correct nevertheless.

Anyone deciding not to hit just because Blue is up 19 pips is missing much of the point. The strength of White's board is a major factor; it is the tipping point that justifies holding one's nose and stacking up on the 4pt rather than making the more natural hitting play.

In Variant 1 below, Blue has the same 19-point lead but White doesn't own her 4pt. In this case, Blue should hit:

		White is Player 2 score: 0 pip: 125 7 point match pip: 144 score: 0 Blue is Player 1
XGID=--a-B-D-C--BbBb--bbcB--c--:0:0:1:42:0:0:0:7:10
Variant 1 Instead of owning her 4pt, White has spares on 6pt and 2pt

1.	Rollout1	8/2*	eq: +0.126
	Player: Opponent: 51.79% (G:16.06% B:0.51%) 48.21% (G:10.67% B:0.42%) Conf.: ± 0.007 (+0.119...+0.133) - [100.0%] Duration: 53 minutes 46 seconds
2.	Rollout1	8/4 6/4	eq: +0.100 (-0.026)
	Player: Opponent: 51.03% (G:13.80% B:0.39%) 48.97% (G:8.06% B:0.30%) Conf.: ± 0.006 (+0.093...+0.106) - [0.0%] Duration: 48 minutes 21 seconds
3.	Rollout2	13/11 13/9	eq: +0.025 (-0.100)
	Player: Opponent: 49.34% (G:12.36% B:0.38%) 50.66% (G:7.27% B:0.23%) Conf.: ± 0.013 (+0.013...+0.038) - [0.0%] Duration: 11 minutes 29 seconds
1 5184 Games rolled with Variance Reduction. Dice Seed: 93559422 Moves: 3-ply, cube decisions: XG Roller 2 1296 Games rolled with Variance Reduction. Dice Seed: 93559422 Moves: 3-ply, cube decisions: XG Roller

In Variant 2 below, White still does not own her 4pt. The margin has swung back partway so that, as in the original position, not hitting is best but now the decision is very close. It is unclear how much of the .036 difference in margin (between Variant 1 and Variant 2) is due to putting White's 2pt spare back into play, and how much if it is due to Blue's race lead being increased (from 19) to 23 pips.

		White is Player 2 score: 0 pip: 129 7 point match pip: 144 score: 0 Blue is Player 1
XGID=--a-B-D-C--BbBb--bbdB--b--:0:0:1:42:0:0:0:7:10
Variant 2 (Both of White's 4pt checkers have been moved to the 6pt)

1.	Rollout1	8/4 6/4	eq: +0.058
	Player: Opponent: 49.89% (G:13.18% B:0.40%) 50.11% (G:8.23% B:0.36%) Conf.: ± 0.004 (+0.053...+0.062) - [99.9%] Duration: 45 minutes 46 seconds
2.	Rollout1	8/2*	eq: +0.048 (-0.010)
	Player: Opponent: 49.85% (G:14.59% B:0.43%) 50.15% (G:10.02% B:0.41%) Conf.: ± 0.005 (+0.043...+0.053) - [0.1%] Duration: 52 minutes 10 seconds
3.	Rollout2	13/11 13/9	eq: -0.021 (-0.079)
	Player: Opponent: 48.14% (G:11.05% B:0.33%) 51.86% (G:6.68% B:0.22%) Conf.: ± 0.012 (-0.033...-0.010) - [0.0%] Duration: 9 minutes 29 seconds
1 10368 Games rolled with Variance Reduction. Dice Seed: 78160250 Moves: 3-ply, cube decisions: XG Roller 2 1296 Games rolled with Variance Reduction. Dice Seed: 78160250 Moves: 3-ply, cube decisions: XG Roller

Variant 3 below is a 2-pip difference from the original position, but that is a negligible factor. Not only does White not own her 4pt, but she has an inside blot. Blue should happily hit, knowing that if he is hit back he will, more often than not, have a nice return shot of his own.

Stacking on the 4pt is repugnant, when you think about it. :)

Nack

		White is Player 2 score: 0 pip: 127 7 point match pip: 144 score: 0 Blue is Player 1
XGID=--a-B-D-C--BbBb--bbcBa-b--:0:0:1:42:0:0:0:7:10
Variant 3 (One of White's 4pt checkers has been moved to her 6pt)

1.	Rollout1	8/2*	eq: +0.046
	Player: Opponent: 49.66% (G:15.23% B:0.49%) 50.34% (G:11.23% B:0.47%) Conf.: ± 0.007 (+0.039...+0.053) - [100.0%] Duration: 44 minutes 34 seconds
2.	Rollout1	6/4 6/2*	eq: +0.003 (-0.043)
	Player: Opponent: 48.67% (G:14.03% B:0.45%) 51.33% (G:11.25% B:0.49%) Conf.: ± 0.007 (-0.004...+0.010) - [0.0%] Duration: 44 minutes 06 seconds
3.	Rollout1	8/4 6/4	eq: -0.014 (-0.060)
	Player: Opponent: 47.91% (G:11.92% B:0.35%) 52.09% (G:8.29% B:0.32%) Conf.: ± 0.006 (-0.020...-0.008) - [0.0%] Duration: 42 minutes 03 seconds
4.	Rollout1	11/9 6/2*	eq: -0.017 (-0.063)
	Player: Opponent: 48.62% (G:14.22% B:0.55%) 51.38% (G:12.42% B:0.55%) Conf.: ± 0.007 (-0.024...-0.010) - [0.0%] Duration: 45 minutes 39 seconds
5.	Rollout1	13/11 13/9	eq: -0.021 (-0.067)
	Player: Opponent: 48.00% (G:10.95% B:0.35%) 52.00% (G:6.97% B:0.26%) Conf.: ± 0.006 (-0.027...-0.015) - [0.0%] Duration: 45 minutes 49 seconds
1 5184 Games rolled with Variance Reduction. Dice Seed: 93559422 Moves: 3-ply, cube decisions: XG Roller

Messages In This Thread

• 42 to play
  Dmitriy Obukhov -- Saturday, 15 September 2018, at 6:29 a.m.
  • 42 to play
    Casper Van der Tak -- Saturday, 15 September 2018, at 7:55 a.m.
  • 42 to play
    ah_clem -- Saturday, 15 September 2018, at 11:23 p.m.
  • 42 to play
    neilkaz -- Monday, 17 September 2018, at 2:25 p.m.
  • 42 to play (ROLLOUT and VARIANTS)
    Nack Ballard -- Saturday, 6 October 2018, at 1:13 a.m.