Computer Chess Club Archives


Search

Terms

Messages

Subject: null move search; disadvantages

Author: Drexel,Michael

Date: 07:24:03 12/26/02


On December 26, 2002 at 07:50:19, Eran wrote:

>I understand that the advantage in Fritz is that the nullmove search does an
>excellent job in middle games, but its disantvantage is that it does not do very
>well in end games especially in some decisive mates. That is why ChessBase
>provides a special mate solve engine for that. Correct me if I am wrong.
>
>Eran

here is a nice example. hope everything is correct this time.

[D] 8/5K2/3N3N/8/5k2/7B/5B2/8 w - - 0 1

this problem was created by Fritz 4 (with a little help of mine) long ago.
white to move and mate in 4

Crafty 19.01 (native CB), Ruffian 1.0.1 (UCI) and Fritz 5.32 find the mate in 4
almost
immediately and showed correct evaluation in analysis mode.

Fritz 7.0.0.8 engine find the mate in 4 too.
the engine showed only a mate in 5 in analysis mode nevertheless.

Shredder 7 dont find mate in 4.
confronted first time with this position Shredder would mate you in 5: 1.Bg2 Kg5
2.Be3+?!

Comet B54 (native CB) is funny.
it announced a mate in 15 and would play it (even without tablebase support)
because
it finds a forced way to convert the position into a won endgame bbk v. k

I know that this is not important regarding playing strength of engines.
most freeware engines find the mate in four immediately
and some of the strongest commercial engines did not find it at all.
if you need an engine for solving chess problems try Crafty or Ruffian first.



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.