Author: Frederik Tack
Date: 14:11:41 12/20/05
I'm looking for the best way to implement a repetition detection in the search tree for my engine without loosing performance. I've found some articles on the internet suggesting to create a repetition table using zobristkeys. I have now implemented this and it works fine, but i've lost about 10% performance. I have now come up with a new idea that should have no impact on performance. However, i'm not sure if what i'm about to do is completely correct. Here's the idea. Before starting the analysis, i store every position i've had on the board from the move history in the transposition table with an evaluation of 0 and a depth of maxdepth + 1. During the analysis, i use a replacement scheme in the transposition table that will not replace the position if the depth in the tree is smaller than depth in the table. Since i've stored the historic positions with maxdepth + 1, they will never get replaced. This should score every position that has been on the board before with a draw score. The fact is i haven't found any article on the internet discussing this way of working, so i fear it may have some drawbacks i'm not aware of. Has any1 tried implementing repetition detection this way or has any1 an idea why this wouldn't work?
This page took 0.01 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.