Computer Chess Club Archives


Search

Terms

Messages

Subject: Rebel's long checks concept in QS

Author: milix

Date: 11:22:28 01/23/04


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!



This page took 0.09 seconds to execute

Last modified: Thu, 07 Jul 11 08:48:38 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.