Author: Louis Fagliano
Date: 10:54:57 01/18/05
On the web site http://www.drb.insel.de/~heiner/Chess/PGN_Standard.txt under section “8.2.3.4: Disambiguation” I quote the following: “In the case of ambiguities (multiple pieces of the same type moving to the same square), the first appropriate disambiguating step of the three following steps is taken: First, if the moving pieces can be distinguished by their originating files, the originating file letter of the moving piece is inserted immediately after the moving piece letter. Second (when the first step fails), if the moving pieces can be distinguished by their originating ranks, the originating rank digit of the moving piece is inserted immediately after the moving piece letter. Third (when both the first and the second steps fail), the two character square coordinate of the originating square of the moving piece is inserted immediately after the moving piece letter.” But it is impossible for both the first and the second steps to fail. If two pieces have the same originating file AND rank, then they are both standing on the same square! The only way that the first and the second steps could fail is if chess were three-dimensional. That last paragraph should be deleted, but I don’t know who the author is. Does anyone know? Another interesting note on section “8.2.3.4: Disambiguation” is the next paragraph: “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’.” I believe in the situation above with the skeleton position White Ke1, Nc3, Ng1 and Black Bb4 if the knight on g1 goes to e2 then ChessBase and all ChessBase programs GUI’s still print out the move as “Nge2” and not “Ne2”. Not that this is a big deal, but there should be some standard set for all GUI’s.
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.