Author: Jaime Benito de Valle Ruiz
Date: 12:46:15 03/21/04
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>No, because I still have the same problem with Elephant. >And I do nearly the same things you described here. Additionaly >I check for repetition when I accept moves and scores from the >hash table. In this case I scan the hash line like I do when >I retrieve the principle variation from hash. For each hashed >move/position I call a special repetition detection function >and when I find a 3. repetition I give the entire line of moves >the draw score. I don't change hashed values but I return the >draw score to previous plies. (A question: what to do if draw >is not in [alpha,beta]?) The problem is, even this time consuming >algorithm does not work. Sometimes I see lines like this in >the output: > 14 248 3201 640337 Kf1-e2 Ra1-a2 Ke2-f1 Ra2-a1 Kf1-e2 Ra1-a2 >Ke2-f1 Ra2-a1 Kf1-e2 Ra1-a2 Ke2-f1 Ra2-a1 Kf1-e2 Ra1-a2 Ke2-f1 Ra2-a1 Kf1-e2 >Ra1-a2 Ke2-f1 Ra2-a1 >with score 248 instead of 0. May be there is an off by one error >or the score finds a secret way out of the search algorithms. :-( >The correct search would see the 0 instead of 248, avoid it and >find a move with score 123 or whatever. > >If you find a solution or anybody else knows it, please let me know. >Is there an easy test position where this must happen? > >Harald All the problems I have had in the past were hash-related, basically. Have you got any debugging tool to check your hash? Try this position, and see what you get: 5nrr/8/k2p3q/p3b3/8/8/7P/2Q4K w - - Regards, Jaime
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