| |
BGonline.org Forums
Correct to double and correct to beaver
Posted By: Daniel Murphy In Response To: Correct to double and correct to beaver (Seth)
Date: Tuesday, 15 June 2010, at 1:19 a.m.
Just to be sure I wasn't hallucinating, Seth, I played your position out 15 times today. I won 13 games and lost no gammons. I was unlucky -- the two games I lost were:
Loss 1: Me 6-1 23/17 19/18* ... Luckbox 6-6 bar/19/13/7*/1 ... I lost
Loss 2: Me 6-6 23/17 22/16 21/15 19/13 ... Luckbox 6-X 7/off ... I lost.
So (not based on these 15 games -- I have played such positions literally thousands of times -- my second backgammon mentor enjoyed rolling out snakes in his spare time) ... White should win
(a) Blue rolls 6-6 and White responds with a 6, a 0.85% chance.
(b) Blue rolls any other 6 and White responds with 6-6, a 0.77% chance. Note that the 23-19 5-prime is one of only three 5-primes that White can clear from the bar (the others are 17-13 and 11-7).
There's nothing Blue can do about sequences (a) and (b).
(c) Blue closes White out and White wins, about a 3% chance.
(d) Blue has miscellaneous accidents along the way that White is able to take advantage of. These occur rarely. Blue should almost always be able to keep a 6 prime intact. Noting that Blue rarely needs to fear a lucky shot from the bar if Blue has at least a 5 prime (or even a 4 prime), Blue can often break a 6 prime if he needs to, for instance by slotting two points in front of the prime, by sending White to the bar while slotting the prime, or even by sending one checker far in front of the snake. Otherwise, the play is fairly routine -- slot the next point in the prime, cover it, repeat. I can't say I know how much these "accidents" add up to, but I'll guess about 5%, giving White about 10% GWC from the initial position. And, except for the unfortunate (a) and (b) sequences, nearly no gammons.
| |
BGonline.org Forums is maintained by Stick with WebBBS 5.12.