Chess Informant Inc developed the Encyclopaedia of Chess Openings which is a system of classification for chess openings into 5 main groups of openings, each of these groups has a 100 different categories of openings.


HIARCS Chess Explorer can classify openings into their ECO codes and further more name the actual openings. You can also access openings by name to practice those openings and also the Player Explorer can classify favourite openings of players and databases.


For reference here is an overview of the ECO codes and opening names:  

  • A00-A99: Flank openings
    • A01 Nimzowitsch-Larsen Attack
    • A02-A03 Bird's Opening
    • A04-A09 Reti Opening
    • A10-A39 English opening
    • A40-42 Queen's Pawn Opening
    • A43 Benoni/Old Benoni
    • A45-A50 Queen's Pawn 1.d4 Nf6
    • A51-A52 Budapest Gambit
    • A53-A55 Old Indian Defence
    • A56 Czech Benoni
    • A57-A59 Benko/Volga Gambit
    • A60-A79 Modern Benoni
    • A80-A99 Dutch Defence
  • B00-B99 Semi-open games (not including the French defence)
    • B00 King's Pawn Opening
    • B01 Scandinavian Defence
    • B02-B05 Alekhine Defence
    • B06 Modern/Robatsch Defence
    • B07-B09 Pirc Defence
    • B10-B19 Caro-Kann Defence
    • B20-B99 Sicilian Defence
  • C00-C99 Open games (including the French defence)
    • C00-C19 French Defence
    • C20 King's Pawn Game
    • C21 Danish Gambit
    • C22 Center Game
    • C23-C24 Bishop's Opening
    • C25-C29 Vienna Game
    • C30-C32 King's Gambit Declined
    • C33-C39 King's Gambit Accepted
    • C40 Latvian Gambit
    • C41 Philidor Defence
    • C42-C43 Petroff Defence, 3.Nxe5
    • C44 Ponziani Opening
    • C45 Scotch Game
    • C46 Three Knights' Game
    • C47-C49 Four Knights' Game
    • C50 Italian Game - Giuoco Pianissimo
    • C51-C52 Evans' Gambit
    • C53-C54 Giuoco Piano, 4.c3
    • C55-C59 Two Knights' Defence
    • C60-C99 Ruy Lopez
  • D00-D99 Closed and semi-closed games
    • D00-D03 Queen's Pawn Game
    • D04-D05 Colle System
    • D06-D09 Queen's Gambit, Irregular
    • D10-D19 Slav Defence
    • D20-D29 Queen's Gambit Accepted
    • D30 Queen's Gambit Declined: Slav
    • D31 Queen's Gambit Declined: Semi-Slav
    • D32-D34 Queen's Gambit Declined: Tarrasch Defence
    • D35-D42 Queen's Gambit Declined
    • D43-D49 Queen's Gambit Declined: Semi-Slav main line
    • D50-D69 Queen's Gambit Declined: Classical
    • D70-D99 Grünfeld Defence
  • E00-E99: Indian defences
    • E00 Indian Defences
    • E01-E09 Catalan Opening
    • E10 Blumenfeld Gambit
    • E11 Bogo-Indian Defence
    • E12-E19 Queen's Indian Defence
    • E20-E59 Nimzo-Indian Defence
    • E60-E99 King's Indian Defence