text: A38 English Opening, Symmetrical: 1...c5 2.Nc3 Nc6 3.g3 g6 4.Bg2 Bg7 5.Nf3 Nf6 (without: 6.0-0 0-0 7.d4 (A39) and 6.d4 cxd4 7.Nxd4 0-0 (A39))
  A39 English Opening, Symmetrical, Main line with 1...c5 2.Nc3 Nc6 3.g3 g6 4.Bg2 Bg7 5.Nf3 Nf6 6.0-0 0-0 7.d4 or 1...c5 2.Nc3 Nc6 3.g3 g6 4.Bg2 Bg7 5.Nf3 Nf6 6.d4 cxd4 7.Nxd4 0-0 8.0-0
  A40–A44
  1.d4 without 1...d5, 1...Nf6 or 1...f5: Atypical replies to 1.d4
  A40 Queen's Pawn Game (including Englund Gambit, Polish Defence, Queen's Knight Defence, Franco-Indian Defence, English Defence and Keres Defence)
  A41 Queen's Pawn Game, Wade Defence
  A42 Modern Defence, Averbakh System also Wade Defence
  A43 Old Benoni Defence
  A44 Old Benoni Defence
  A45–A49
  1.d4 Nf6 without 2.c4: Atypical replies to 1...Nf6
  A45 Queen's Pawn Game, Trompowsky Attack
  A46 Queen's Pawn Game, Torre Attack
  A47 Queen's Indian Defence
  A48 King's Indian, East Indian Defence
  A49 King's Indian, Fianchetto without c4
  A50–A79
  1.d4 Nf6 2.c4 without 2...e6 or 2...g6: Atypical Indian systems
  A50 Queen's Pawn Game (including Black Knights' Tango)
  A51 Budapest Gambit Declined
  A52 Budapest Gambit
  A53 Old Indian Defence
  A54 Old Indian, Ukrainian Variation
  A55 Old Indian, Main line
  A56 Benoni Defence
  A57 Benko Gambit
  A58 Benko Gambit Accepted
  A59 Benko Gambit, 7.e4
  A60 Benoni Defence
  A61 Benoni Defence
  A62 Benoni, Fianchetto Variation without early ...Nbd7
  A63 Benoni, Fianchetto Variation, 9...Nbd7