Eco Code System Explained

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ECO (Encyclopedia of Chess Openings) is a unique system of classifying all main chess openings by 500 codes from A00 to E99

The Eco Code System was invented by Chess Informant in year 1966

In this Game it's C50 - Blackburne Shilling Gambit. The Main Trap mates in 7!


Click on Eco codes or Interval will to go to the Openings

Eco A: Flank Openings (Without 1. d4 and 1. e4)


  • A00-A39 Flank Openings (neither 1.d4 nor 1.e4) - includes English Opening


  • A40-A44 Queens Pawn Opening without 1..d5 or 1..f5 or 1..Nf6 reply


  • A45-A49 Queens Pawn, Indian Defence 1.d4 Nf6 without 2.c4


  • A50-A79 Queens Pawn, Indian Defence  with 2.c4 but without 2..e6 or 2..g6


  • A80-A99 Queens Pawn with 1..f5 reply (Dutch Defence)



Eco B: Semi-Open Games other than the French Defence (1. e4)


  • B00-B19 Kings Pawn without 1..c5, ..1.e6 or ..1.e5 - incl. Alekhine, Caro-Kann Defence


  • B20-B99 Kings Pawn with 1..c5 reply (Sicilian Defence)



Eco C: Open Games and the French Defence (1. e4)


  • C00-C19 Kings Pawn with 1..e6 reply (French Defence)


  • C20-C99 Kings Pawn with 1..e5 reply (Mutual King's Pawn, incl. Ruy Lopez)



Eco D: Closed Games and Semi-Closed Games (1. d4)


  • D00-D05 Queens Pawn Game 1.d4 d5 without 2.c4


  • D06-D69 Queens Pawn Game 1.d4 d5 with 2.c4 (Queen's Gambit)


  • D70-D99 Queens Pawn Indian Defence. (1.d4 Nf6, 2.c4 g6) with early ..d5 (Gruenfeld Defence)



Eco E: Indian Defences (1. d4)


  • E00-E59 Queens Pawn Indian Defence. (1.d4 Nf6) with 2.c4 e6 - includes Catalan Opening


  • E60-E99 Kings Indian Defence. (1.d4 Nf6, 2.c4 g6) without early ..d5 (King's Indian)