ECO C42
34 named openings and variations are classified as C42. ECO (Encyclopaedia of Chess Openings) codes group openings from A00 to E99 by their opening moves.
- Petrov's DefenseC421. e4 e5 2. Nf3 Nf6
- Petrov's Defense: Classical AttackC421. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4
- Petrov's Defense: Classical Attack, Berger VariationC421. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 d5 6. Bd3 Be7 7. O-O Nc6 8. Re1 Bg4 9. c3 f5 10. Nbd2
- Petrov's Defense: Classical Attack, Chigorin VariationC421. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 d5 6. Bd3 Be7 7. O-O Nc6 8. Re1
- Petrov's Defense: Classical Attack, Chigorin Variation, Browne AttackC421. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 d5 6. Bd3 Nc6 7. O-O Be7 8. c4 Nb4 9. cxd5
- Petrov's Defense: Classical Attack, Chigorin Variation, Main LineC421. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 d5 6. Bd3 Nc6 7. O-O Be7 8. c4 Nb4 9. Be2
- Petrov's Defense: Classical Attack, Closed VariationC421. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 Nf6
- Petrov's Defense: Classical Attack, Jaenisch VariationC421. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 d5 6. Bd3 Nc6 7. O-O Be7 8. c4
- Petrov's Defense: Classical Attack, Krause VariationC421. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 d5 6. Bd3 Nc6 7. O-O Be7 8. Re1 Bg4 9. c3 f5 10. c4
- Petrov's Defense: Classical Attack, Marshall TrapC421. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 d5 6. Bd3 Bd6 7. O-O O-O 8. c4 Bg4 9. cxd5 f5 10. Re1 Bxh2+
- Petrov's Defense: Classical Attack, Marshall VariationC421. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 d5 6. Bd3 Bd6
- Petrov's Defense: Classical Attack, Marshall Variation, Chinese GambitC421. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 d5 6. Bd3 Bd6 7. O-O O-O 8. c4 c6 9. Re1 Bg4
- Petrov's Defense: Classical Attack, Maróczy VariationC421. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 d5 6. Bd3 Be7 7. O-O Nc6 8. Re1 Bg4 9. c3 f5 10. c4 Bh4
- Petrov's Defense: Classical Attack, Mason VariationC421. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 d5 6. Bd3 Be7 7. O-O O-O
- Petrov's Defense: Classical Attack, Mason-Showalter VariationC421. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 d5 6. Bd3 Nc6
- Petrov's Defense: Classical Attack, Staunton VariationC421. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 d5 6. Bd3 Bd6 7. O-O O-O 8. c4 c6
- Petrov's Defense: Classical Attack, Tarrasch VariationC421. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 d5 6. Bd3 Bd6 7. O-O O-O 8. c4 Bg4
- Petrov's Defense: Cochrane GambitC421. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nxf7
- Petrov's Defense: Cochrane Gambit, Bishop Check LineC421. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nxf7 Kxf7 5. Bc4+
- Petrov's Defense: Cochrane Gambit, Center VariationC421. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nxf7 Kxf7 5. d4
- Petrov's Defense: Cozio AttackC421. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. Qe2
- Petrov's Defense: Damiano VariationC421. e4 e5 2. Nf3 Nf6 3. Nxe5 Nxe4
- Petrov's Defense: Damiano Variation, Kholmov GambitC421. e4 e5 2. Nf3 Nf6 3. Nxe5 Nxe4 4. Qe2 Qe7
- Petrov's Defense: French AttackC421. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d3
- Petrov's Defense: Italian VariationC421. e4 e5 2. Nf3 Nf6 3. Bc4
- Petrov's Defense: Karklins-Martinovsky VariationC421. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nd3
- Petrov's Defense: Kaufmann AttackC421. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. c4
- Petrov's Defense: Millennium AttackC421. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. Bd3
- Petrov's Defense: Moody GambitC421. e4 e5 2. Nf3 Nf6 3. Qe2 Nc6 4. d4
- Petrov's Defense: Nimzowitsch AttackC421. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. Nc3
- Petrov's Defense: Paulsen AttackC421. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nc4
- Petrov's Defense: Stafford GambitC421. e4 e5 2. Nf3 Nf6 3. Nxe5 Nc6
- Petrov's Defense: Stafford Gambit AcceptedC421. e4 e5 2. Nf3 Nf6 3. Nxe5 Nc6 4. Nxc6 dxc6
- Petrov's Defense: Three Knights GameC421. e4 e5 2. Nf3 Nf6 3. Nc3