[Bug-gnubg] Problems with Stop rollout when one move appears to be best

[Neil Robins]

I find that when rolling out more than two moves there are various problems that sometimes happen if this box is checked:

 

1. A move that has come back within the set JSDs only sometimes not always restarts rolling.

2. A move that has gone way beyond the set JSDs sometimes continues to roll.

3. The whole rollout can stop with some rolls neither rolled to maximum number of trials nor outside the set JSDs.

 

I think these problems happen generally when the plays don't fall out of contention from the bottom of the list up. Stopping and restarting the rollout with them reordered gets the right moves rolling again.

 

Try this Example:

 

 GNUBgID: hucZAxDYzmDABg:8AmmAAAAIAAA

Roll out the top five 2-ply moves, using :  

Full cubeful rollout with var.redn.
        1296 games, Mersenne Twister dice gen. with seed 359697340 and quasi-random dice
        Stop when best play is enough JSDs ahead: limit 3.1 (min. 217 games)
        Play: 0-ply cubeful [expert]
        Cube: 0-ply cubeful [expert]

 

If you have more time even more problems can be seen rolling out the same moves in the same position using 2-ply with a different seed same box checked same JSDs (my initial rollout):

 1296 games, Mersenne Twister dice gen. with seed 859697340 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]