rnbqkb1r/ppp2ppp/3p4/8/3Pn3/5N2/PPP2PPP/RNBQKB1R b KQkq - 0 5 ; C42 Petrov's Defense: Classical Attack
r2qk2r/ppp1b1pp/2n5/3p1p2/3Pn1b1/2PB1N2/PP1N1PPP/R1BQR1K1 b kq - 1 10 ; C42 Petrov's Defense: Classical Attack, Berger Variation
r1bqk2r/ppp1bppp/2n5/3p4/3Pn3/3B1N2/PPP2PPP/RNBQR1K1 b kq - 5 8 ; C42 Petrov's Defense: Classical Attack, Chigorin Variation
r1bqk2r/ppp1bppp/8/3P4/1n1Pn3/3B1N2/PP3PPP/RNBQ1RK1 b kq - 0 9 ; C42 Petrov's Defense: Classical Attack, Chigorin Variation, Browne Attack
r1bqk2r/ppp1bppp/8/3p4/1nPPn3/5N2/PP2BPPP/RNBQ1RK1 b kq - 2 9 ; C42 Petrov's Defense: Classical Attack, Chigorin Variation, Main Line
rnbqkb1r/ppp2ppp/3p1n2/8/3P4/5N2/PPP2PPP/RNBQKB1R w KQkq - 1 6 ; C42 Petrov's Defense: Classical Attack, Closed Variation
r1bqk2r/ppp1bppp/2n5/3p4/2PPn3/3B1N2/PP3PPP/RNBQ1RK1 b kq - 0 8 ; C42 Petrov's Defense: Classical Attack, Jaenisch Variation
r2qk2r/ppp1b1pp/2n5/3p1p2/2PPn1b1/3B1N2/PP3PPP/RNBQR1K1 b kq - 0 10 ; C42 Petrov's Defense: Classical Attack, Krause Variation
rn1q1rk1/ppp3pp/8/3P1p2/3Pn1b1/3B1N2/PP3PPb/RNBQR1K1 w - - 0 11 ; C42 Petrov's Defense: Classical Attack, Marshall Trap
rnbqk2r/ppp2ppp/3b4/3p4/3Pn3/3B1N2/PPP2PPP/RNBQK2R w KQkq - 2 7 ; C42 Petrov's Defense: Classical Attack, Marshall Variation
rn1q1rk1/pp3ppp/2pb4/3p4/2PPn1b1/3B1N2/PP3PPP/RNBQR1K1 w - - 2 10 ; C42 Petrov's Defense: Classical Attack, Marshall Variation, Chinese Gambit
r2qk2r/ppp3pp/2n5/3p1p2/2PPn1bb/3B1N2/PP3PPP/RNBQR1K1 w kq - 1 11 ; C42 Petrov's Defense: Classical Attack, Maróczy Variation
rnbq1rk1/ppp1bppp/8/3p4/3Pn3/3B1N2/PPP2PPP/RNBQ1RK1 w - - 4 8 ; C42 Petrov's Defense: Classical Attack, Mason Variation
r1bqkb1r/ppp2ppp/2n5/3p4/3Pn3/3B1N2/PPP2PPP/RNBQK2R w KQkq - 2 7 ; C42 Petrov's Defense: Classical Attack, Mason-Showalter Variation
rnbq1rk1/pp3ppp/2pb4/3p4/2PPn3/3B1N2/PP3PPP/RNBQ1RK1 w - - 0 9 ; C42 Petrov's Defense: Classical Attack, Staunton Variation
rn1q1rk1/ppp2ppp/3b4/3p4/2PPn1b1/3B1N2/PP3PPP/RNBQ1RK1 w - - 1 9 ; C42 Petrov's Defense: Classical Attack, Tarrasch Variation