C30Black1 book lines continue
Classical Variation, Rubinstein Countergambit
King's Gambit Declined1. e4 e5 2. f4 Bc5 3. Nf3 d6 4. c3 f5 5. fxe5 dxe5 6. d4 exd4
Also known as KGD: Classical Countergambit, King's Gambit Declined, Classical Variation, Rubinstein Countergambit.