pgn-extract: A Portable Game Notation (PGN) Manipulator for Chess Games

The program is designed to make it easy to extract selected games from a PGN format data file based on a wide variety of criteria. The criteria include:

textual move sequences;

the position reached after a sequence of moves;

information in the tag fields;

fuzzy board position;

and material balance in the ending.

The program includes a semantic analyser which will report errors in game scores and it is also able to detect duplicate games found in its input files.

The range of input move formats accepted is fairly wide and includes recognition of lower-case piece letters for English and upper-case piece letters for Dutch and German. The output is normally in English Standard Algebraic Notation (SAN), but this can be varied.

Extracted games may be written out either including or excluding comments, NAGs, variations, move numbers, tags and/or results. Games may be given ECO classifications derived from the accompanying file eco.pgn, or a customised version provided by the user.