Author: José de Jesús García Ruvalcaba
Date: 10:22:31 06/05/99
Go up one level in this thread
On June 04, 1999 at 20:20:38, Dave Gomboc wrote: >On June 04, 1999 at 19:39:36, Mike Leahy wrote: > >>On May 27, 1999 at 20:48:55, Dann Corbit wrote: >> >>>From the PGN Standard >> >> >>>16.1.4: Examples >>> >>>Here's the FEN for the starting position: >>> >>>rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1 >>> >>>And after the move 1. e4: >>> >>>rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq e3 0 1 >> >>This is problematic. The position is identical to... >> >> rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq - 0 1 > >The position you describe with the string not containing "e3" is not technically >reachable (even ignoring the ply count for now) because Black can't lose a move >while White slides a pawn first to e3, then to e4. > If we ignore the ply counts, then the position is reachable: 1. e3 Nc6 2. Bd3 Nb8 3. Be2 Nc6 4. Bf1 Nb8 5. e4 Of course, the last digit for the fen string would now be 5 instead of 1, since it follows black's fifth move. >My personal opinion is that the standard should be that an en passant square is >only specified if an en passant capture is actually possible, and "-" is always >used otherwise. However, this wasn't SJE's choice. I can imagine various >justifications that might be made for his choice, but none so strong that they >override the clarity of our preferred format. > >While you are toying around with Bookup EPD handling, please allow assessments >to be in the range -32768 to 32767, or at least automatically translate between >this range and the range -10000 to 9999 when importing and exporting into/from >Bookup. Currently it is annoying to deal with the issue of checkmates in my >opening analysis, I have to find that a score is missing in the first place, >followed by entering it by hand. > >>...because the en passant capture is not legal. Purely >>positional programs like Bookup are fussy about this. >>Bookup considers the record with 'e3' as illegal. Programs >>like Rebel solve the program by ignoring the en passant flag(!). > >Does Rebel ignore the "e3" or "-" if the position actually does allow an en >passant capture, or just if no en passant capture is possible? If the former, >it's buggy! If the latter, excellent input handling! :) > >>Mike Leahy > >Dave
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