├── C43 - 1. e4 e5 2. Nf3 Nf6 3. d4 Nxe4 4. Bd3 d5 5. Nxe5 Nd7 6. Nc3 - Petrov's Defense: Modern Attack, Center Variation (4) ├── C43 - 1. e4 e5 2. Nf3 Nf6 3. d4 Nxe4 4. Bd3 d5 5. Nxe5 Nd7 6. Nxd7 - Petrov's Defense: Modern Attack, Center Variation (7) └── C43 - 1. e4 e5 2. Nf3 Nf6 3. d4 Nxe4 4. Bd3 d5 5. Nxe5 Nd7 6. O-O - Petrov's Defense: Modern Attack, Center Variation (4)
