Author: Kai Lübke
Date: 01:28:13 10/08/98
Go up one level in this thread
On October 08, 1998 at 02:03:56, blass uri wrote: > >On October 07, 1998 at 23:33:53, James T. Walker wrote: > >>I gave Fritz 5.16 a position /p4K/P////k// W. I think that I have that figured >>out right. Anyway, Fritz announces #14 after about 16 sec. But when you go >>through the moves it announces #13 twice, #10 twice,#8 followed by #9 etc. It >>jumps from #6 to #4 no matter what move I make in that position. After that it >>counts on down to mate properly. It ends up with about a mate in 17. What >>causes this phenom ? Crafty with the same position announces #17 on the first >>move then while pondering it finds mate in 15. After that it counts down by one >>to mate. That seems fairly normal. >>Jim > >Fritz never knew to count >It was designed to play chess and not to count the number of moves to mate > >I think that this is because of hash tables >Maybe fritz found that some position leads to mate and remember it in the hash >tables as mate without the number of moves > >After it go to the same position again in the search it evaluates it as >checkmate without number of moves and this is the reason that it cannot count The "mate in 8, then on the next move mate in 9" stuff is something you often see in Fritz engines (Hiarcs and Junior have the same problems sometimes). Crafty has a special code that assures that a "mate in N" is never followed by a "mate in N+k" where k>=0. I'm just waiting for someone to find a position where Fritz will not be able to mate because of this... :-) --- Shep
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.