Author: milix
Date: 12:26:39 01/23/04
Go up one level in this thread
On January 23, 2004 at 14:53:17, Harald Lüßen wrote: >On January 23, 2004 at 14:22:28, milix wrote: >>I tried to implement the long checks idea of Ed Schröder >>(http://members.home.nl/matador/chess840.htm#QS) but not worked for me. >>Maybe my QS is not implemented correctly to have this checks concept but I can't >>figure it by myself. I wish for some help here (maybe from Ed himself) :-) >> >>In my main search, before I enter the QS I set the variable MAX_CHECKS_DEPTH to >>2. >> >>My quiescent in pseudo code: >> >>quiescent(alpha, beta) >>{ >> save the MAX_CHECKS_DEPTH >> score = full_evaluate() >> if (score < alpha) return score > >Change the last line to >if (score >= beta) return beta; >And again >if (score >= beta) return beta; > >> if (score > alpha) alpha = score; >> } >> MAX_CHECKS_DEPTH = MAX_CHECKS_DEPTH - 1 >> >> return alpha >>} >> >>Thanks in advance! > >Harald Thanks for the response but this didn't work also. Returning beta seems to not work with long checks concept (I get wrong evaluations and bad moves). Ed writes in his article: Get_a_Move_Until_No_More_Moves -> following the move ordering if (Lazy_Eval_is_true) -> done, return score, see elsewhere Evaluate_Position(); if (Trick_one_is_true) -> done, return score, see elsewhere if (move_does_check_the_opponent_king) -> go one ply deeper in QS if (ALPHA >= SCORE) -> done, return score if (Trick_two_is_true) -> done, return score, see elsewhere else: go one ply deeper in QS I do not use Lazy_Eval, Trick_one and Trick_two. When I return when alpha >= score get correct move but I doesn't found the mates. For example: 2k4r/ppp5/2p1b1Q1/4q3/3bP3/3B2P1/PPP1N2P/5R1K b - - 0 26 it see the Rxh2 but evaluates it with -4.86, not mate score 5n2/B3K3/2p2Np1/4k3/7P/3bN1P1/2Prn1P1/1q6 w - - 0 1 doesn't find the mate The long checks concept supposed that it will find these mates in the first iteration of main search (and it does in Rebel) but it doesn't for me...
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