Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Ten years later: revising EPD/FEN/PGN

Author: Rafael Andrist

Date: 02:51:01 09/10/03

Go up one level in this thread


On September 09, 2003 at 18:33:22, Steven Edwards wrote:

>FEN: One deficiency exists for which I take responsibility; the en passant
>target square semantics should indicate a non null value only if an active >colorpawn attacks the passed-over target square.  A change here will improve >position database operation and can also have a positive effect on internal >transposition management.

Yes, this really needs to be changed. I think most chess engines do this
already, as it is necessary to see some transpositions and to access the Nalimov
EGTB.

Because of the backward compatibility, an engine should also accept a FEN with
an illegal e.p. square and set it to zero automatically.

And there is also another question which needs to be adressed: what if the
requirements re the pawn structure are given, but the pawn is pinned to the
king? In this case e.p. is not possible - but using your description above, the
e.p. square would be set. I think it takes little time to verify this.


>4. The centipawn evaluation operand type needs a mate score indication
>correction.

I suggest to use always "dm" to indicate a mate and "om" (=opponent mates) to
indicate a loss [see also http://www.talkchess.com/forums/1/message.html?314978]
and not to use "ce" in these cases, so "ce" would just mean the centi-pawn
evaluation of the program if there is no mate/loss around.


regards
Rafael B. Andrist



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.