What to do?

Here’s a situation that arose yesterday during the ongoing G. v D. money session at GCCRC.

Should “O” double? If so, should “X” take?

The score (after 0 games) is: P0 82, P1 107 Match Information: Date: April 13, 2007 Move number 6: O on roll, cube decision? GNU Backgammon Position ID: 3lkAANj5AQAAAA Match ID : AgEAACAFWAMA +12-11-10--9--8--7-------6--5--4--3--2--1-+ O: P0 (Cube: 4) | | | O O O | O 82 points | | | O O O | O On roll | | | O O | O | | | O | O | | | 6 | ^| |BAR| | | | | | X | | | X | X | | | X X | X | | | X X X | X | | | X X X X | X 107 points +13-14-15-16-17-18------19-20-21-22-23-24-+ X: P1 Pip counts: O 32, X 33

I’ve done a rollout using gnuBG, but I’ll wait a couple of days before posting the result. In the meantime, post your opinion/reasoning using the Comment box below (sorry, no prizes for correct answers).

Cube analysis Rollout cubeless equity +0.142 Cubeful equities: 1. No double +0.302 2. Double, pass +1.000 ( +0.69 3. Double, take +0.007 ( -0.295) Proper cube action: No redouble, take (29.7%) Rollout details: Player P0 owns 4-cube: 0.571 0.000 0.000 - 0.429 0.000 0.000 CL +0.142 CF +0.302 [0.000 0.000 0.000 - 0.000 0.000 0.000 CL 0.000 CF 0.000] Player P1 owns 8-cube: 0.571 0.000 0.000 - 0.429 0.000 0.000 CL +0.284 CF +0.007 [0.000 0.000 0.000 - 0.000 0.000 0.000 CL 0.000 CF 0.000] Full cubeful rollout with var.redn. 60656 games, Mersenne Twister dice gen. with seed 1057640406 and quasi-random dice Play: supremo 2-ply cubeful prune [world class] keep the first 0 0-ply moves and up to 16 more moves within equity 0.32 Skip pruning for 1-ply moves. Cube: 2-ply cubeful prune [world class]