Library, Learning & Reference Materials

The short 3 digit alpha-numeric codes, printed alongside many published chess games are "ECO" codes, and they are a way of classifying the opening moves of a chess game.

Some chess players will be familiar with ECO classification and may even be able to identify their own particular favourite opening lines, such as a "B90" or a "C74". However, more often than not, these codes will be over-looked, as being little more than cryptic id keys, useful only to modern chess computer databases.

The ECO classification system originates from a 5 volume book (now also a database) that was first published by the Serbian company, Šahovski informator (Chess Informant). in 1966. This encylopoedic work is compiled by notable chess players, and it aims to categorise the opening moves of hundreds of thousands of master games.

'Informator' is designed to bridge language barriers and so it contains very limited amounts of text (shown in in eight languages). The bulk of the books contains diagrams of positions and chess moves that are shown in International figurine algebraic notation. Rather than using language, special symbols are used to comment the moves ('Chess Punctuation'). The moves are then provided in a table format that concisely presents the best opening lines.

To further bridge language barriers, traditional opening names are not used. The original five volumes of 'Informator' were categorised from, "A" to "E", and each book focused on broadly different catagories of opening. Generally, Volume 'A' dealt with 'Flank' openings, 'B' dealt with 'Semi-Open' lines, 'C' with 'Open' lines, 'D' with 'Closed'lines and 'E' with 'Indian' openings. However, as this work was originally being produced in a printed format, some adjustments were needed, to accomodate the publisher's printing requirements and effectively 'balance' the 5 volumes. This is why, some openings, such as the French Defence, may appear to be mis-categorised.

In the western speaking world, this notable work become known as the 'Encylopoedia of Chess Openings' or 'ECO' for short. Popular publications and moden chess database systems have since adopted this coding system and use of ECO classification is now widedspread.