Author: Robert Hyatt
Date: 10:07:54 02/06/02
Go up one level in this thread
On February 06, 2002 at 11:25:38, Miguel A. Ballicora wrote: >On February 06, 2002 at 10:54:24, Heiner Marxen wrote: > >>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. > >This is the way that human players have used it always. Not only I do no think >it is not a bug decision, but I think it was the right decision. >The algebraic notation is a human notation, not a computer one. > >Regards, >Miguel > > > Personally I like the convention, and have _always_ used it. There was a time (perhaps still as I haven't looked at the code) where either xboard or ICC didn't handle this right, which caused me to put in a kludge for that case and not use legality for disambiguating moves. I agree with you that SAN is for humans, and I don't consider illegal moves at all and therefore see no reason to have to deal with them just because computers are a bit more short-sighted (at lease some programs are). Of course, there are _still_ programs that output zero-zero for castling, so who would be surprised if they can't handle legality checks properly? :)
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