Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Zugzwang position

Author: Heiner Marxen

Date: 07:54:24 02/06/02

Go up one level in this thread


On February 06, 2002 at 07:12:57, Gian-Carlo Pascutto wrote:

>On February 06, 2002 at 06:35:22, Hans van der Zijden wrote:
>
>>With white to move Fritz thinks white is just a little bit better and it gives
>>the move R1e2, which is strange because there is only 1 rook that can go to e2.
>
>Fritz _may_ be correct. I'm not 100% sure I remember it correctly,
>but I don't think the SAN standard specifies that you don't have to
>disambiguate moves if some of them are not actually legal due to
>checks.

Unfortunately not true.  SAN talks about legal moves, only, and thus
disambiguates only between legal moves:

8.2.3.4: Disambiguation
[...]
Note that the above disambiguation is needed only to distinguish among moves of
the same piece type to the same square; it is not used to distinguish among
attacks of the same piece type to the same square.  An example of this would be
a position with two white knights, one on square c3 and one on square g1 and a
vacant square e2 with White to move.  Both knights attack square e2, and if
both could legally move there, then a file disambiguation is needed; the
(nonchecking) knight moves would be "Nce2" and "Nge2".  However, if the white
king were at square e1 and a black bishop were at square b4 with a vacant
square d2 (thus an absolute pin of the white knight at square c3), then only
one white knight (the one at square g1) could move to square e2: "Ne2".

This is considered a design bug by some, but it is the current state of affairs.

>--
>GCP

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.