C49White32 book lines continue
Spanish Variation, Double Spanish
Four Knights Game1. e4 e5 2. Nf3 Nc6 3. Nc3 Nf6 4. Bb5 Bb4 5. O-O O-O 6. d3
Also known as Four Knights: Double Bishops, 6.d3, Four Knights Game: Double Spanish, with 5. O-O, Four Knights Game, Double Spanish Misc. with 5.O-O.