Black to Play 6-1
Thanks for posting such an interesting and difficult position.
White’s backgame defense is relatively well-timed in this position. Getting hit by Black will not create very much difficulty for him. If Black does hit, and is then unable to convert to a forward game, the hit will only improve White’s timing.
If Black does not hit, then White will have only one checker trapped behind Black’s block. If White is succesful in escaping this checker, then Black would prefer to be hit in the process. In the unlikely event that White’s runner is unable to escape, then Black wants to make his 4pt. Either circumstance calls for slotting the 4pt. Of course, Black must play his 6 by jumping over White’s prime.
Below are the results of a truncated rollout in GnuBg, version 1.02. This rollout uses
settings that mimic XGR++. It has hitting trailing the slot by 0.03. On the Ballard/Weaver error scale that is enough to qualify as an error, albeit, a small one. The XG error reported by Fllecha, however, is getting close to whopper territory.
A request for Fllecha: please include an XGID or GnuBg ID along with your board diagrams. Thanks.
Mike
Code:
Position ID: bNuEAxBwuwEANw
Match ID: UQkHAAAAAAAE
1. Rollout 23/17 5/4 Eq.: -0.735064
0.314198 0.027668 0.000746 - 0.685802 0.405680 0.094037 CL -0.842906 CF -0.735064
[0.001259 0.000582 0.000043 - 0.001259 0.001136 0.001042 CL 0.002961 CF 0.003333]
Truncated cubeful rollout (depth 5) with var.redn.
360 games, Mersenne Twister dice gen. with seed 709502359 and quasi-random dice
Play: world class 2-ply cubeful prune [world class]
keep the first 0 0-ply moves and up to 8 more moves within equity 0.16
Skip pruning for 1-ply moves.
Cube: 2-ply cubeful prune [world class]
Different evaluations after 2 plies:
Play: 1-ply cubeful prune
keep the first 0 0-ply moves and up to 8 more moves within equity 0.16
Cube: 2-ply cubeful prune [world class]
2. Rollout 23/16* Eq.: -0.766023 ( -0.030959)
0.267478 0.049184 0.002117 - 0.732522 0.380540 0.063564 CL -0.857847 CF -0.766023
[0.001064 0.000544 0.000059 - 0.001064 0.001274 0.000892 CL 0.002624 CF 0.002900]
Truncated cubeful rollout (depth 5) with var.redn.
360 games, Mersenne Twister dice gen. with seed 709502359 and quasi-random dice
Play: world class 2-ply cubeful prune [world class]
keep the first 0 0-ply moves and up to 8 more moves within equity 0.16
Skip pruning for 1-ply moves.
Cube: 2-ply cubeful prune [world class]
Different evaluations after 2 plies:
Play: 1-ply cubeful prune
keep the first 0 0-ply moves and up to 8 more moves within equity 0.16
Cube: 2-ply cubeful prune [world class]