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Meh checker play problem. Bot Data

Posted By: Michael Depreli
Date: Saturday, 2 February 2013, at 12:48 p.m.

In Response To: Meh checker play problem. (Michael Depreli)

Like all the other respondents I played 8/5 6/4 in a heartbeat. XG 3-Ply had that tied with 13/8 but XGR++ dinged me for it (-0.011).

Really? I thought. I took a look at some of white's follow up plays after each move. It did play some moves differently but no glaring errors.

The rollout insists 13/8 is better and 8/5 6/4 is third behind 6/4 6/3

GNU likes 8/5 6/4 on 2-ply but it too overturned this on a rollout preferring 13/8

Assume blue plays 13/8, white rolls 51 and plays 8/3 6/5 and once again blue rolls 32. XGR++ again prefers 13/8.

		White is Player 2 score: 0 pip: 142 7 point match pip: 139 score: 0 Blue is Player 1
XGID=------EbE---dC-B-bacb-a---:0:0:1:32:0:0:0:7:10
Blue to play 32

1.	XG Roller++	13/8	eq: +0.123
	Player: Opponent: 54.13% (G:2.10% B:0.06%) 45.87% (G:2.93% B:0.05%)
2.	XG Roller++	8/5 6/4	eq: +0.109 (-0.014)
	Player: Opponent: 53.79% (G:2.10% B:0.07%) 46.21% (G:2.85% B:0.05%)
3.	XG Roller++	6/4 6/3	eq: +0.105 (-0.018)
	Player: Opponent: 53.68% (G:2.11% B:0.06%) 46.32% (G:2.94% B:0.05%)

eXtreme Gammon Version: 2.03, MET: Kazaross XG2

So unless someone can show XG is misplaying this position or some other explanation then as Stick suggested:

13/8 could well be correct preparing to get the midpoint down to 2 checkers thus allowing some doublets to play better bringing both outfield points closer to home.

		White is Player 2 score: 0 pip: 148 7 point match pip: 144 score: 0 Blue is Player 1
XGID=------EbD---dD-B-cada-----:0:0:1:32:0:0:0:7:10
Blue to play 32

1.	Rollout1	13/8	eq: +0.163
	Player: Opponent: 54.94% (G:2.09% B:0.08%) 45.06% (G:2.90% B:0.08%) Conf.: ± 0.002 (+0.161...+0.165) - [99.9%] Duration: 1 hour 34 minutes
2.	Rollout1	6/4 6/3	eq: +0.158 (-0.005)
	Player: Opponent: 54.78% (G:2.12% B:0.08%) 45.22% (G:3.03% B:0.09%) Conf.: ± 0.002 (+0.156...+0.160) - [0.1%] Duration: 1 hour 35 minutes
3.	Rollout2	8/5 6/4	eq: +0.156 (-0.007)
	Player: Opponent: 54.79% (G:2.08% B:0.08%) 45.21% (G:2.94% B:0.09%) Conf.: ± 0.002 (+0.154...+0.158) - [0.0%] Duration: 1 hour 29 minutes
1 22389 Games rolled with Variance Reduction. Moves and cube decisions: 3-ply 2 22388 Games rolled with Variance Reduction. Moves and cube decisions: 3-ply

eXtreme Gammon Version: 2.03, MET: Kazaross XG2

Like I said it's a bit Meh with not of equity at stake but for those who worry about each little 0.001...

Michael