Author: Bruce Moreland
Date: 22:13:12 03/14/98
I just discovered what appears to be a serious problem with PGN: its "NAG" set (those funky "$" things you find in PGN files) is incompatible with the Informant's symbol set (also used in ECO). For example, if you are reading through ECO and encounter a symbol that looks like a little circle, it means "greater board room", which I interpret to mean "space advantage". PGN has several ways of specifying a space advantage. Six of them, as a matter of fact: 24 White has a slight space advantage 25 Black has a slight space advantage 26 White has a moderate space advantage 27 Black has a moderate space advantage 28 White has a decisive space advantage 29 Black has a decisive space advantage The problem is that none of these mean precisely "space advantage", they all mean something inconveniently more. If you are writing a PGN reader, and you want to display Informant symbols, you could map all of these onto the circle symbol, but how do you export the circle symbol back out to a PGN file? There are numerous other examples of this, as a matter of fact, almost all of the PGN NAGs suffer from this problem. It is hard to even interpret something very simple like the Informant symbol "=", which in Informant-language means simply "equal". In PGN you'd have to choose between: 10 drawish position 11 equal chances, quiet position 12 equal chances, active position What a mess! I think that what happened here is that Steven tried to specify something that was forward-looking, he decided to try to superset the Informant symbols. But what he did instead was make all of the Informant symbols untranslatable. Also affected are the NIC symbols, which seem to be a fairly proper subset of the Informant symbols, with many of the same incompatibilities with PGN. Is there anything that can be done to circumvent these problems, or any reasonable and non-glacial way to fix the PGN standard in such a way that its NAGS are compatible with existing standards? bruce
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