The Encyclopedia of Chess Openings established a classification system for openings. Unfortunately, the classification is more thematic rather than a strict codification; this makes it difficult to present ECO codes using traditional computing techniques. Also, after a couple of moves, openings regularly transpose into alternative themes. The letter prefixing an opening (A-E), references one of the five volumes in the encyclopedia.

To compensate, we present here a few different ways of following opening moves;

ECO Coding

You can follow the opening themes by ECO code

By Move

You can develop themes by following move sequences

Enter an ECO code to list openings matching it

Type all or part of a name to search for; this will find both main lines and variations

Navigation through these links references a database of opening positions which are cross referenced to each other and the corresponding ECO classification. Where possible, ECO names are used. At present these openings are offered without commentary. The database of positions was constructed using data files created by Franz Hemmer. You can download them yourself. At present, the database consists of over 2000 positions under the 499 ECO classfications.