Doubling is usually well played in holding games but what about when there is only one checker behind. Black on roll. Answer in spoiler.
Score is 0-0 (5 point match). Pip count: Black 123, White 135.
Spoiler
There is three important things in this kind of positions. Prime & number of points, distribution of checkers and of course race.
Weak side can usully take in normal 10 % down racing lead or so but if the distribution is good for leader or there is any kind of prime (for example three points together) then it is a pass. Or vica verse if the race is even then with good distribution or prime, leader still might just have a double but it's clear take.
Cube analysis
Rollout cubeless equity +0,641 (Money: +0,636)
Cubeful equities:
1. Double, pass +1,000
2. Double, take +1,188 ( +0,188)
3. No double +0,945 ( -0,055)
Proper cube action: Double, pass
Rollout details:
Centered 1-cube:
0,752 0,159 0,002 - 0,248 0,028 0,001 CL +0,641 CF +0,945
[0,001 0,002 0,000 - 0,001 0,001 0,001 CL 0,003 CF 0,007]
Player Trystman owns 2-cube:
0,760 0,167 0,001 - 0,240 0,027 0,002 CL +1,364 CF +1,188
[0,002 0,003 0,000 - 0,002 0,001 0,001 CL 0,010 CF 0,013]
Full cubeful rollout with var.redn.
791 games, Mersenne Twister dice gen. with seed 825396884 and quasi-random dice
Play: 0-ply cubeful prune [expert]
Cube: 0-ply cubeful prune [expert]
Quote from: blitzxz on April 28, 2008, 01:12:01 PM
Doubling is usually well played in holding games but what about when there is only one checker behind. Black on roll. Answer in spoiler.
Score is 0-0 (5 point match). Pip count: Black 123, White 135.
Spoiler
There is three important things in this kind of positions. Prime & number of points, distribution of checkers and of course race.
Weak side can usully take in normal 10 % down racing lead or so but if the distribution is good for leader or there is any kind of prime (for example three points together) then it is a pass. Or vica verse if the race is even then with good distribution or prime, leader still might just have a double but it's clear take.
Cube analysis
Rollout cubeless equity +0,641 (Money: +0,636)
Cubeful equities:
1. Double, pass +1,000
2. Double, take +1,188 ( +0,188)
3. No double +0,945 ( -0,055)
Proper cube action: Double, pass
Rollout details:
Centered 1-cube:
0,752 0,159 0,002 - 0,248 0,028 0,001 CL +0,641 CF +0,945
[0,001 0,002 0,000 - 0,001 0,001 0,001 CL 0,003 CF 0,007]
Player Trystman owns 2-cube:
0,760 0,167 0,001 - 0,240 0,027 0,002 CL +1,364 CF +1,188
[0,002 0,003 0,000 - 0,002 0,001 0,001 CL 0,010 CF 0,013]
Full cubeful rollout with var.redn.
791 games, Mersenne Twister dice gen. with seed 825396884 and quasi-random dice
Play: 0-ply cubeful prune [expert]
Cube: 0-ply cubeful prune [expert]
Spoiler
I was the 1st voter, and the 1st sucker, lol. I thought that white may well escape black's onslaught and then there will be an even race. If black can't make a point next rolls, white will do a more normal bear-in and this might be of help, if white can run away. There are also rolls for black that would leave him with direct and indirect shots, like 6-5.Just my thoughts
By the way, would you plz provide us with 2-ply analysis?
Spoiler
6-5 is the only roll that gives any shots and even then black is just ok to hit loose. 6-3 is a hit and point. 6-2 from mid point and 5-2 is a new point. Majority of rolls makes new points for black. White to win black must roll couple bad rolls in row and then leave a shot or white could just run over black even though he is now 10 % behind and might get trapped. But this is just what happened in the actual game. :) White got his lucky shot after all and won the game. Gammons are also important here. Lot more then I thought.
2 ply rollout takes a while but sure.
Spoiler
I'm the dummy who voted double/pass. Vici would yell at me because black has no 6 move and is 2 away. I'd probably do it anyway. The pass because of position.
socksey
The worst moment for an atheist is when he feels grateful and has no one to thank. -- Wendy Ward
Spoiler
Here is very short 2-ply rollout with narrow filter. Difference is clear with only 250 games and I don't have now time to make longer rollout.
Cube analysis
Rollout cubeless equity +0,633 (Money: +0,634)
Cubeful equities:
1. Double, pass +1,000
2. Double, take +1,169 ( +0,169)
3. No double +0,940 ( -0,060)
Proper cube action: Double, pass
Rollout details:
Centered 1-cube:
0,747 0,174 0,002 - 0,253 0,035 0,001 CL +0,633 CF +0,940
[0,002 0,004 0,001 - 0,002 0,002 0,000 CL 0,006 CF 0,012]
Player X owns 2-cube:
0,759 0,170 0,003 - 0,241 0,031 0,001 CL +1,357 CF +1,169
[0,003 0,006 0,001 - 0,003 0,002 0,000 CL 0,017 CF 0,018]
Full cubeful rollout with var.redn.
251 games, Mersenne Twister dice gen. with seed 825264581 and quasi-random dice
Play: 2-ply cubeful prune [world class]
keep the first 0 0-ply moves and up to 8 more moves within equity 0,12
Skip pruning for 1-ply moves.
Cube: 2-ply cubeful prune [world class]