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Deliberate practice with XG

Posted By: Albert Steg
Date: Saturday, 11 June 2016, at 1:11 p.m.

The other day I enjoyed hitting a first checker in a 'coup classique' position. Though I succeeded in eventually closing out both checkers and winning after a recipe, there were a lot of plays where I wasn't sure what I should be trying to do, so I thought it would be worthwhile spending some time playing it out repeatedly as a 'Deliberate Practice' exercise.

Right away, though, as I started cycling through the 21 dice rolls for the opening position, I found the evaluation depth for some of the likely plays were so low that the results were way off. With an initial 23 for example, it buries 13/8 way down in 10th place, while if you roll out both plays you get 13/8 beating out 8/5 6/4 by .013.

Okay . . so I get that XG tends to be unreliable in back game / lopsided containment positions. But then, when I tried "Play from Position" in Coaching Mode with "Champion" as my opponent, XG promptly affirms that 13/8 is the right play (see second position below) -- via a '+' level evaluation. (Though I'm still thinking just making the 8-pt should be right by a larger margin?). It also quickly picks 13/8 if I use "++ Roller" as opponent.

So, my question is

a) If I want to go through all 21 rolls in this position, what's the most efficient and reliable way for me to go about it?

and

b) If I practice playing out this position on, say 'Champion' level, can I be confident I'm getting good guidance from XG in 'Coaching' mode?

Any help appreciated.

Evaluating a 23 in "++" mode:

 White is Player 2 score: 0 pip: 25 Unlimited GameJacoby Beaver pip: 175 score: 0 Blue is Player 1
XGID=--a-BBC-A----B-----AB-AaA-:1:1:1:32:0:0:3:0:10
Blue to play 32

1.XG Roller++8/5 6/4eq: -0.243
 Player:Opponent: 47.48% (G:0.00% B:0.00%)52.52% (G:23.00% B:13.01%)
2.XG Roller++19/16 8/6eq: -0.276 (-0.033)
 Player:Opponent: 46.71% (G:0.00% B:0.00%)53.29% (G:24.08% B:13.42%)
3.XG Roller++20/17 8/6eq: -0.290 (-0.047)
 Player:Opponent: 46.15% (G:0.00% B:0.00%)53.85% (G:24.40% B:13.21%)
4.XG Roller++22/20 8/5eq: -0.329 (-0.086)
 Player:Opponent: 45.32% (G:0.00% B:0.00%)54.68% (G:25.16% B:14.35%)
5.4-ply19/17 8/5eq: -0.399 (-0.156)
 Player:Opponent: 43.07% (G:0.00% B:0.00%)56.93% (G:25.19% B:16.02%)
6.4-ply22/19 8/6eq: -0.466 (-0.223)
 Player:Opponent: 42.51% (G:0.00% B:0.00%)57.49% (G:28.40% B:18.25%)
7.3-ply20/18 8/5eq: -0.400 (-0.157)
 Player:Opponent: 42.67% (G:0.00% B:0.00%)57.33% (G:24.62% B:15.72%)
8.2-ply20/17 19/17eq: -0.598 (-0.355)
 Player:Opponent: 37.27% (G:0.00% B:0.00%)62.73% (G:29.52% B:17.99%)
9.2-ply13/10 8/6eq: -0.601 (-0.358)
 Player:Opponent: 39.32% (G:0.00% B:0.00%)60.68% (G:29.87% B:22.73%)
10.2-ply13/8eq: -0.622 (-0.379)
 Player:Opponent: 38.07% (G:0.00% B:0.00%)61.93% (G:29.61% B:22.13%)

eXtreme Gammon Version: 2.10

Playing from Position on "Champion" level opponent:

 White is Champion score: 0 pip: 25 Unlimited GameJacoby Beaver pip: 175 score: 0 Blue is Player 1
XGID=--a-BBC-A----B-----AB-AaA-:1:1:1:32:0:0:3:0:10
Blue to play 32

1.XG Roller++20/17 8/6eq: -0.290
 Player:Opponent: 46.15% (G:0.00% B:0.00%)53.85% (G:24.40% B:13.21%)
2.XG Roller++22/20 8/5eq: -0.329 (-0.039)
 Player:Opponent: 45.32% (G:0.00% B:0.00%)54.68% (G:25.16% B:14.35%)
3.XG Roller+13/8eq: -0.188 (+0.102)
 Player:Opponent: 49.30% (G:0.00% B:0.00%)50.70% (G:21.29% B:13.47%)
4.XG Roller+8/5 6/4eq: -0.205 (+0.086)
 Player:Opponent: 48.96% (G:0.00% B:0.00%)51.04% (G:23.47% B:12.17%)
5.XG Roller+19/16 8/6eq: -0.224 (+0.066)
 Player:Opponent: 48.63% (G:0.00% B:0.00%)51.37% (G:23.54% B:13.25%)

eXtreme Gammon Version: 2.10

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