ECO C66

ECO C00–C99 — Open Games and the French Defense: 1.e4 e6 and 1.e4 e5, from the Italian and Ruy Lopez to the King's Gambit.

7 named opening lines are classified under ECO code C66.

• Ruy Lopez: Berlin Defense, Closed Bernstein Variation — 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.O-O d6 5.d4 Bd7 6.Nc3 Be7 7.Bg5
• Ruy Lopez: Berlin Defense, Closed Showalter Variation — 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.O-O d6 5.d4 Bd7 6.Nc3 Be7 7.Bxc6
• Ruy Lopez: Berlin Defense, Closed Wolf Variation — 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.O-O d6 5.d4 Bd7 6.Nc3 exd4
• Ruy Lopez: Berlin Defense, Hedgehog Variation — 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.O-O d6 5.d4 Bd7 6.Nc3 Be7
• Ruy Lopez: Berlin Defense, Improved Steinitz Defense — 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.O-O d6
• Ruy Lopez: Berlin Defense, Tarrasch Trap — 1.e4 e5 2.Nf3 Nc6 3.Bb5 d6 4.d4 Bd7 5.Nc3 Nf6 6.O-O Be7 7.Re1 O-O
• Ruy Lopez: Closed Berlin Defense, Chigorin Variation — 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.O-O d6 5.d4 Nd7