Author: Heiner Marxen
Date: 13:25:27 05/19/01
Go up one level in this thread
On May 19, 2001 at 14:51:11, leonid wrote: >Hi! > >Today had very busy day mainly because should go into library and had few thing >to do at home. Will later look into your description. But do you remember what >is about your file that sound like "Mate 2"? It is not about searching mate at >two plys deep? Hi, yes, it is about searching mate, but in 2 moves (i.e. 3 plies, to be exact). It is about reducing the attacker's candidates for a mate-in-2 solution. But be warned, this is a very complex part of Chest. > It is the occasion when many shortening in the search process >could be done. Attacker can generate only checking moves and for responding side >only one legal move will be enough to say that mate not existe. Without taking >in consideration this special character of last two plys, general searching >process will go some 40% longer. Now I don't remember for what depth I looked >when I found this. For the last ply, where the attacker is to deliver mate-in-1, Chest has a special move generator (move1gen() in move1gen.c). For the second-last ply, where the defender tries to find a move not followed by mate, Chest has the "answer heuristic": answer.c provides a sort function on defender's move list. fac.c provides functions, to recognize many cases, where a defender can check the attacker, who in turn is so busy to deal with the check, that he does not find any reource to mate the defender. Such a "fatal anti check" immediately solves the job of the defender within a mate-in-2, without executing the move. All of these make a better first reading than "mate2.c". What the heck ... just read them all ;-) Cheers, Heiner
This page took 0 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.