Arimaa Forum - Print Page


    
      
        Arimaa Forum
        (http://arimaa.com/arimaa/forum/cgi/YaBB.cgi)
      

        Arimaa >> Bot Development >> Search in Bomb
        
(Message started by: fotland on Feb 11^th, 2007, 6:06pm)

Title: Search in Bomb
Post by fotland on Feb 11^th, 2007, 6:06pm

The basic search in Bomb is a pretty ordinary alpha-beta search.

I use iterative deepening, by steps. The first iteration does a 3 step search, then each iteration increases the depth by 1 step.

The first iteration does a simple alpha-beta search, with alpha=-32000 and beta=+32000. The later iterations use PVS search.

The first move is searched with a full window (-32000 to 32000), and the remaining moves are searched with a minimal window (alpha, alpha+1).

I tried using an aspiration search on later iterations with a window or + or - 2 rabbits around alpha from the last iteration, but it was slower. I think the evaluation is not stable enough from step to step.

After each iteration I try the best move first in the next iteration, but otherwise leave to move order unchanged in the first ply.