ECO Codes
These days, you will often find a short 3 digit alpha-numeric code, printed alongside many published chess games. These codes are known as "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 eded, 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.
For reference, a more detailed ECO Classification is given below.
ECO | Opening |
---|---|
A00 | Irreg. (incl. Grob; Polish [Solosky]) |
A01 | Nimzovich-Larsen attack |
A02 | Bird (incl.From gambit) |
A03 | Bird's Opening : Lasker variation |
A04 | Reti |
A05 | Reti : King's Indian attack |
A06 | Reti : Old Indian attack |
A07 | Reti : King's Indian attack |
A08 | Reti : King's Indian attack |
A09 | Reti : Advance variation & Keres var |
A10-A39 | English Opening |
A40 | Queen's pawn |
A41 | Old Indian defence |
A42 | Modern Robatsch |
A43 | Old Benoni : Franco-Benoni defence |
A44 | Old Benoni defence |
A45 | Trompowsky & d4 Irreg. |
A46 | Queen's pawn game |
A47 | Queen's Indian defence |
A48 | King's Indian : East Indian defence |
A49 | King's Indian : Fianchetto without c4 |
A50 | Queen's pawn game |
A51 | Budapest Defence |
A52 | Budapest defence |
A53-A55 | Old Indian defence |
A56 | Benoni defence |
A57-A59 | Benko gambit |
A60-A79 | Benoni defence |
A80-A99 | Dutch |
ECO | Opening |
---|---|
B00 | King's Pawn irreg. (incl Nimzowitch Def) |
B01 | Scandinavian gambit (incl Centre Counter) |
B02-B05 | Alekhine's defence |
B06 | Robatsch (Modern) defence |
B07-B09 | Pirc |
B10-B19 | Caro-Kann defence |
B20 | Sicilian Defence (wing) |
B21 | Grand Pix / Smith Morra |
B22 | Alapin |
B23-B26 | Closed |
B27-B288 | O'Kelly variation |
B29-B31 | Nimzovich-Rubinstein variation |
B32 | Labourdonnais-Loewenthal (Kalashnikov) |
B33 | Pelikan (Lasker/Sveshnikov) variation |
B34-B39 | Accelerated Fianchetto |
B40 | Anderssen variation |
B41-B43 | Kan variation |
B44 | Sicilian, Szen, hedgehog variation |
B45-B49 | Taimanov variation |
B50 | wing gambit deferred |
B51 | Canal-Sokolsky |
B52 | Canal-Sokolsky attack, 3...Bd7 |
B53 | Sicilian, Chekhover variation |
B54-B55 | Prins variation, Venice attack |
B56 | Venice attack |
B57 | Sozin, not Scheveningen |
B58-B59 | Boleslavsky variation |
B60-B69 | Richter-Rauzer |
B70-B79 | Dragon variation |
B80-B85 | Scheveningen variation |
B86-B89 | Sozin attack |
B90-B99 | Najdorf |
ECO | Opening |
---|---|
C01 | French : Exchange variation |
C02 | French : Advance variation |
C03-C09 | French : Tarrasch |
C10 | French : Rubinstein variation |
C11 | French : Burn variation |
C12 | French : MacCutcheon variation |
C13 | French : Albin-Alekhine-Chatard attack |
C14 | French : Classical variation |
C15-C19 | French : Winawer (Nimzovich) variation |
C20 | Alapin's Opening |
C21 | Centre game (Danish Gambit) |
C22 | Centre game |
C23-C24 | Bishop's Opening |
C25-C29 | Vienna Game/Vienna Gambit |
C30 | King's Gambit Declined |
C31-C32 | KGD (Falkbeer) |
C33 | KGA |
C34 | KGA King's knight's gambit |
C35 | KGA : Cunningham defence |
C36 | KGA : Abbazia defence |
C37 | KGA Muzio Lolli Variations |
C38 | KGA : Greco gambit |
C39 | KGA : Allgaier gambit, kieseritsky |
C40 | Others incl Damiano, Latvian |
C41 | Philidor |
C42-C43 | Petrov |
C44 | Ponziani, Scotch |
C45 | Scotch game |
C46 | Three knights game |
C47-C49 | Four knights |
C50-C55 | Giuoco Piano (incl Evans) |
C56-C59 | Two Knights Defence |
C60 | Cozio |
C61 | Bird's Defence |
C62 | Ruy Lopez : Old Steinitz defence |
C63 | Ruy Lopez : Schliemann defence |
C64 | Ruy Lopez : Classical (Cordel) defence |
C65 | Ruy Lopez : Berlin defence |
C66 | Ruy Lopez : Closed Berlin defence |
C67 | Berlin Def |
C68-C69 | Ruy Lopez : Exchange variation |
C70 | Ruy Lopez : Alapin's defence deferred |
C71-C76 | Ruy Lopez : Modern Steinitz defence |
C77 | Ruy Lopez : Morphy defence |
C78 | Ruy Lopez : Archangelsk |
C79 | Ruy Lopez : Steinitz defence deferred |
C80 | Ruy Lopez : Open (Tarrasch) defence |
C81 | Ruy Lopez : Open, Howell attack |
C82 | Ruy Lopez : Open, Dilworth variation |
C83 | Ruy Lopez : Open, 9...Be7, 10.Re1 |
C84 | Ruy Lopez : Closed defence |
C85 | Ruy Lopez : Exchange doubly deferred |
C86 | Ruy Lopez : Worrall attack |
C87 | Ruy Lopez : Closed, Averbach variation |
C88 | Ruy Lopez : Closed |
C89 | Ruy Lopez : Marshall counter-attack |
C90-C99 | Ruy Lopez : Closed |
ECO | Opening |
---|---|
D00 | Q Pawn, Blackmar gambit |
D01 | Richter-Veresov attack |
D02 | Queen's pawn game |
D03 | Torre attack |
D04 | Queen's pawn game |
D05 | Colle system |
D06 | QGD |
D07 | QGD : Chigorin defence |
D08 | QGD : Albin counter-gambit |
D09 | QGD : Albin counter-gambit, 5.g3 |
D10-D19 | QGD Slav |
D20-D25 | Queen's gambit accepted |
D26-D29 | QGA : Classical variation |
D30-D31 | QGD : Slav & semi Slav |
D32-D34 | QGD : Tarrasch defence |
D35-D36 | QGD : Exchange variation |
D37-D39 | QGD : Ragozin variation |
D40-D42 | QGD : Semi-Tarrasch defence |
D43-D49 | QGD Semi-Slav (Incl Meran) |
D50 | QGD : Canal (Venice) variation |
D51 | QGD : Alekhine variation |
D52 | QGD : Cambridge Springs defence |
D53 | QGD : Lasker variation |
D54 | QGD : Anti-neo-Orthodox variation |
D55 | QGD : Neo-Orthodox variation |
D56-D57 | QGD : Lasker defence |
D58-D59 | QGD : Tartakower variation |
D60-D69 | QGD : Orthodox defence |
D70-D99 | Neo-Gruenfeld defence |
ECO | Opening |
---|---|
E00 | Neo-Indian (Seirawan) Attack |
E00 | Catalan Opening |
E01 | Catalan : Closed |
E02 | Catalan : Open, 5.Qa4 |
E03 | Catalan : Open, Alekhine Variation |
E03 | Catalan : Open, 5.Qa4 Nbd7, 6.Qxc4 |
E04 | Catalan : Open, 5.Nf3 |
E05 | Catalan : Open, Classical Line |
E06 | Catalan : Closed, 5.Nf3 |
E07 | Catalan : Closed, 6...Nbd7 |
E07 | Catalan : Closed, Botvinnik Variation |
E08 | Catalan : Closed, 7.Qc2 |
E08 | Catalan : Closed, Zagoryansky Variation |
E08 | Catalan : Closed, Qc2 & B3 |
E08 | Catalan : Closed, Spassky Gambit |
E09 | Catalan : Closed, Main Line |
E09 | Catalan : Closed, Sokolsky Variation |
E10 | Queen's Pawn Game |
E10 | Blumenfeld Counter-Gambit |
E10 | Blumenfeld Counter-Gambit Accepted |
E10 | Blumenfeld Counter-Gambit, Dus-Chotimursky Variation |
E10 | Blumenfeld Counter-Gambit, Spielmann Variation |
E10 | Dzindzikhashvili Defence |
E10 | Doery Defence |
E11 | Bogo-Indian Defence |
E11 | Bogo-Indian Defence, Gruenfeld Variation |
E11 | Bogo-Indian Defence, Nimzovich Variation |
E12 | Queen's Indian Defence |
E12 | Queen's Indian : Miles Variation |
E12 | Queen's Indian : Petrosian System |
E12 | Queen's Indian : 4.Nc3 |
E12 | Queen's Indian : 4.Nc3, Botvinnik Variation |
E13 | Queen's Indian : 4.Nc3, Main Line |
E14 | Queen's Indian : 4.E3 |
E14 | Queen's Indian : Averbakh Variation |
E15 | Queen's Indian : 4.G3 |
E15 | Queen's Indian : Nimzovich Variation (Exaggerated Fianchetto) |
E15 | Queen's Indian : 4.G3 Bb7 |
E15 | Queen's Indian : Rubinstein Variation |
E15 | Queen's Indian : Buerger Variation |
E16 | Queen's Indian : Capablanca Variation |
E16 | Queen's Indian : Yates Variation |
E16 | Queen's Indian : Riumin Variation |
E17 | Queen's Indian : 5.Bg2 Be7 |
E17 | Queen's Indian : Anti-Queen's Indian System |
E17 | Queen's Indian : Opovcensky Variation |
E17 | Queen's Indian : Old Main Line, 6.O-O |
E17 | Queen's Indian : Euwe Variation |
E18 | Queen's Indian : Old Main Line, 7.Nc3 |
E19 | Queen's Indian : Old Main Line, 9.Qxc3 |
E20 | Nimzo-Indian Defence |
E20 | Nimzo-Indian : Kmoch Variation |
E20 | Nimzo-Indian : Mikenas Attack |
E20 | Nimzo-Indian : Romanishin-Kasparov (Steiner) System |
E21 | Nimzo-Indian : Three Knights Variation |
E22 | Nimzo-Indian : Spielmann Variation |
E23 | Nimzo-Indian : Spielmann, 4...C5, 5.Dc Nc6 |
E23 | Nimzo-Indian : Spielmann, Karlsbad Variation |
E23 | Nimzo-Indian : Spielmann, San Remo Variation |
E23 | Nimzo-Indian : Spielmann, Staahlberg Variation |
E24 | Nimzo-Indian : Saemisch, Botvinnik Variation |
E25 | Nimzo-Indian : Saemisch Variation |
E26 | Nimzo-Indian : Saemisch, O'Kelly Variation |
E27 | Nimzo-Indian : Saemisch Variation |
E28 | Nimzo-Indian : Saemisch Variation |
E29 | Nimzo-Indian : Saemisch, Main Line |
E29 | Nimzo-Indian : Saemisch, Capablanca Variation |
E30 | Nimzo-Indian : Leningrad Variation |
E31 | Nimzo-Indian : Leningrad, Main Line |
E32 | Nimzo-Indian : Classical Variation |
E33 | Nimzo-Indian : Classical, Milner-Barry (Zurich) Variation |
E34 | Nimzo-Indian : Classical, Noa Variation |
E35 | Nimzo-Indian : Classical, Noa Variation, 5.Cd Ed |
E36 | Nimzo-Indian : Classical, Botvinnik Variation |
E36 | Nimzo-Indian : Classical, Noa Variation, Main Line |
E37 | Nimzo-Indian : Classical, Noa Variation, Main Line, 7.Qc2 |
E37 | Nimzo-Indian : Classical, San Remo Variation |
E38 | Nimzo-Indian : Classical, 4...C5 |
E39 | Nimzo-Indian : Classical, Pirc Variation |
E40 | Nimzo-Indian : 4.E3 |
E41 | Nimzo-Indian : E3, Huebner Variation |
E42 | Nimzo-Indian : 4.E3 C5, 5.Ne2 (Rubinstein) |
E43 | Nimzo-Indian : Fischer Variation |
E44 | Nimzo-Indian : Fischer Variation, 5.Ne2 |
E45 | Nimzo-Indian : 4.E3, Bronstein (Byrne) Variation |
E46 | Nimzo-Indian : 4.E3 O-O |
E46 | Nimzo-Indian : Reshevsky Variation |
E47 | Nimzo-Indian : 4.E3 O-O, 5.Bd3 |
E48 | Nimzo-Indian : 4.E3 O-O, 5.Bd3 D5 |
E49 | Nimzo-Indian : 4.E3, Botvinnik System |
E50 | Nimzo-Indian : 4.E3 E8G8, 5.Nf3, Without ...D5 |
E51 | Nimzo-Indian : 4.E3, Ragozin Variation |
E52 | Nimzo-Indian : 4.E3, Main Line With ...B6 |
E53 | Nimzo-Indian : 4.E3, Main Line With ...C5 |
E53 | Nimzo-Indian : 4.E3, Keres Variation |
E53 | Nimzo-Indian : 4.E3, Gligoric System With 7...Nbd7 |
E54 | Nimzo-Indian : 4.E3, Gligoric System, Smyslov Variation |
E55 | Nimzo-Indian : 4.E3, Gligoric System, Bronstein Variation |
E56 | Nimzo-Indian : 4.E3, Main Line With 7...Nc6 |
E57 | Nimzo-Indian : 4.E3, Main Line With 8...Dc And 9...Cd |
E58 | Nimzo-Indian : 4.E3, Main Line With 8...Bxc3 |
E59 | Nimzo-Indian : 4.E3, Main Line |
E60 | King's Indian Defence |
E60 | King's Indian : Anti-Gruenfeld |
E60 | King's Indian : Danube Gambit |
E60 | King's Indian : 3.G3, Counterthrust Variation |
E61 | King's Indian Defence, 3.Nc3 |
E61 | King's Indian : Smyslov System |
E62 | King's Indian : Fianchetto Variation |
E62 | King's Indian : Fianchetto, Larsen System |
E62 | King's Indian : Fianchetto, Kavalek (Bronstein) Variation |
E62 | King's Indian : Fianchetto, Simagin Variation |
E63 | King's Indian : Fianchetto, Panno Variation |
E64 | King's Indian : Fianchetto, Yugoslav System |
E65 | King's Indian : Fianchetto, Yugoslav, 7.O-O |
E66 | King's Indian : Fianchetto, Yugoslav Panno |
E67 | King's Indian : Fianchetto, Classical Variation |
E68 | King's Indian : Fianchetto, Classical Variation, 8.E4 |
E69 | King's Indian : Fianchetto, Classical Main Line |
E70 | King's Indian : Kramer System |
E70 | King's Indian : Accelerated Averbakh System |
E71 | King's Indian : Makagonov System (5.H3) |
E72 | King's Indian With E4 & G3 |
E72 | King's Indian : Pomar System |
E73 | King's Indian : 5.Be2 |
E73 | King's Indian : Semi-Averbakh System |
E73 | King's Indian : Averbakh System |
E74 | King's Indian : Averbakh, 6...C5 |
E75 | King's Indian : Averbakh, Main Line |
E76 | King's Indian : Four Pawns Attack |
E77 | King's Indian : Four Pawns Attack |
E77 | King's Indian : Four Pawns Attack, Florentine Gambit |
E78 | King's Indian : Four Pawns Attack, With Be2 And Nf3 |
E79 | King's Indian : Four Pawns Attack, Main Line |
E80 | King's Indian : Saemisch Variation |
E81 | King's Indian : Saemisch, 5...O-O |
E81 | King's Indian : Saemisch, Byrne Variation |
E82 | King's Indian : Saemisch, Double Fianchetto Variation |
E83 | King's Indian : Saemisch, 6...Nc6 |
E83 | King's Indian : Saemisch, Ruban Variation |
E83 | King's Indian : Saemisch, Panno Formation |
E84 | King's Indian : Saemisch, Panno Main Line |
E85 | King's Indian : Saemisch, Orthodox Variation |
E86 | King's Indian : Saemisch, Orthodox, 7.Nge2 C6 |
E87 | King's Indian : Saemisch, Orthodox, 7.D5 |
E87 | King's Indian : Saemisch, Orthodox, Bronstein Variation |
E88 | King's Indian : Saemisch, Orthodox, 7.D5 C6 |
E89 | King's Indian : Saemisch, Orthodox Main Line |
E90 | King's Indian : 5.Nf3 |
E90 | King's Indian : Larsen Variation |
E90 | King's Indian : Zinnowitz Variation |
E91 | King's Indian : 6.Be2 |
E91 | King's Indian : Kazakh Variation |
E92 | King's Indian : Classical Variation |
E92 | King's Indian : Andersson Variation |
E92 | King's Indian : Gligoric-Taimanov System |
E92 | King's Indian : Petrosian System |
E92 | King's Indian : Petrosian System, Stein Variation |
E93 | King's Indian : Petrosian System, Main Line |
E94 | King's Indian : Orthodox Variation |
E94 | King's Indian : Orthodox, Donner Variation |
E94 | King's Indian : Orthodox, 7...Nbd7 |
E95 | King's Indian : Orthodox, 7...Nbd7, 8.Re1 |
E96 | King's Indian : Orthodox, 7...Nbd7, Main Line |
E97 | King's Indian : Orthodox, Aronin-Taimanov Variation (Yugoslav Attack / Mar Del Plata Variation) |
E97 | King's Indian : Orthodox, Aronin-Taimanov, Bayonet Attack |
E98 | King's Indian : Orthodox, Aronin-Taimanov, 9.Ne1 |
E99 | King's Indian |