Author: Robert Hyatt
Date: 07:08:15 01/20/99
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On January 19, 1999 at 20:20:48, Larry Griffiths wrote: >I ran my program with Alpha-Beta and without Alpha-beta. >The scores and moves chosen were different. > >Is this normal for Alpha-Beta or is this an indication of an >error in my implementation of Alpha-Beta pruning? > It's a bug. Alpha/beta _must_ produce the exact same result as minimax, this was proven in "An analysis of Alpha/Beta Pruning" written by Knuth and Moore, 1975.... > > >Also, The time is 1052.58 seconds without Alpha-Beta >and 3.3 seconds with Alpha-Beta. > >What ratio of elapsed time would indicate that I have achieved >good move ordering etc. with the Alpha-Beta pruning? there is no easy answer. If you do no search extensions, and no quiescence search you could use the alpha/beta 'formula' to compare AB nodes with minimax nodes and see if the rsult is correct...
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