Author: Omid David Tabibi
Date: 15:26:40 01/23/04
Go up one level in this thread
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 > if (score > alpha) alpha = score > > if (side_to_move_is_in_check) > generate_legal_moves() > else if (MAX_CHECKS_DEPTH > 0) > generate_good_equal_captures_queenpromotions_and_checks() > else generate_good_equal_captures_queenpromotions() > sort_the_moves() > > for each move in the list { > make_the_move() > score = - quiescent(-beta, -alpha) > undo_the_move() > restore MAX_CHECKS_DEPTH > if (score < alpha) return score; > if (score > alpha) alpha = score; > } > MAX_CHECKS_DEPTH = MAX_CHECKS_DEPTH - 1 > > return alpha >} > >Thanks in advance! In addition to the points mentioned by others, why don't you send max_checks_depth as a function parameter to quiescence? That will make the code more readable. In Falcon I use a different method for checks in quiescence, but if I switch to Ed's method: [D]5n2/B3K2p/2p2Np1/4k3/7P/3bN1P1/2Prn1P1/1q6 w - - 0 1 depth time nodes nps score variation 3/23 0.01 2k 259k 0.03 1.e3g4 e5f5 2.g4h6 f5e5 3.h6f7 4/63 0.03 6k 222k 0.03 1.e3g4 e5f5 2.g4h6 f5e5 3.h6f7 e5f5 4.f7d6 5/63 0.06 11k 196k #30 1.e3g4++ 5/63 0.08 15k 191k #30 1.e3g4 e5f5 2.g4h6 f5e5 3.h6f7 e5f5 4.f7d6 f5e5 5.f6g4 e5d5 6.g4e3 d5e5 7.d6f7 e5e4 8.f7g5 e4e5 9.g5f3 e5e4 10.f3d2 e4e5 11.d2f3 e5e4 12.f3g5 e4e5 13.g5f7 e5e4 14.f7d6 e4e5 15.e3g4 e5d5 16.g4f6 d5e5 17.d6f7 e5f5 18.f7h6 f5e5 19.h6g4 e5f5 20.g4e3 f5e5 21.f6g4 e5e4 22.g4f2 e4e5 23.f2d3 e5e4 24.d3f2 e4e5 25.f2g4 e5e4 26.g4f6 e4e5 27.e3c4 e5f5 28.c4d6 f5e5 29.f6g4 e5d5 30.c2c4 Works as intended :)
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