Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Saavedra study wrong?!

Author: h.g.muller

Date: 05:13:27 02/09/06

Go up one level in this thread


On February 09, 2006 at 07:24:29, Joseph Tadeusz wrote:

>Perhaps only two kings on the board is less of a draw than stalemate?

You hit upon an interesting pronblem of TB play: for positions in the draw
sector the program hasn't the slightest idea what to play (except avoiding
losing moves). Where for a human there are draws that you are happy with to
salvage and draws that you couldn't win by a hair's breadth, the TB simply does
not make that distinction.

So a TB-driven engine in a drawn KbppKb game with unlike bishops would see
nothing strange in sacrificing one pawn on the first move, a second pawn on the
second move, and its bishop on the third move. KKb is still a draw, so why the
fuss? Of course in KKb there is absolutely no hope left for a swindle, while if
the opponent did not have the KbppKb TB he might have conceivably made a
mistake...

This problem is not so easy to solve, because to maximize the probablilty to
seduce the opponent to a losing error requires knowledge on which type of errors
he is likely to make. The obvious method of keeping the number of non-losing
moves as small as possible would only work against an opponent that plays the
moves randomly. In practice it leads to quick conversion, because if I capture
his Rook in, say, KrpKr, only the single move that recaptures the Rook is
non-losing. But in practice it is of course inconceivable he would refrain from
recapturing the Rook, so the result is certain conversion to a drawn KpK
end-game that is so trivial that he can not possibly bungle it, even if he does
not have that TB...



This page took 0.01 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.