ECO C42 · Petrov's Defense

Petrov's Defense: Classical Attack, Jaenisch Variation

1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 d5 6. Bd3 Nc6 7. O-O Be7 8. c4

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Black to move. The arrow shows Stockfish’s best move.
Best move

8… Nb4+0.40

White is slightly better. Stockfish 18, depth 18.

Analyze this position

In the Petrov's Defense: Classical Attack, Jaenisch Variation (C42), reached after 1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 d5 6. Bd3 Nc6 7. O-O Be7 8. c4, Stockfish 18 recommends 8… Nb4 for Black. White is slightly better (+0.40).

Top engine moves

  1. +0.408… Nb4 9. Be2 O-O 10. Nc3 Be6 11. Ne5 Bf6 12. Bf4 Bxe5 13. dxe5
  2. +0.508… Nf6 9. Nc3 O-O 10. h3 dxc4 11. Bxc4 Na5 12. Bd3 Nc6 13. Re1
  3. +0.538… O-O 9. cxd5 Qxd5 10. Nc3 Nxc3 11. bxc3 Bf5 12. Bf4 Bxd3 13. Qxd3

Frequently asked questions

What is the best move in the Petrov's Defense: Classical Attack, Jaenisch Variation?
After 1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 d5 6. Bd3 Nc6 7. O-O Be7 8. c4, Stockfish 18 at depth 18 recommends 8… Nb4 for Black, continuing 9. Be2 O-O 10. Nc3 Be6 11. Ne5 Bf6 12. Bf4 Bxe5 13. dxe5. White is slightly better (+0.40). The next best moves are 8… Nf6 (+0.50) and 8… O-O (+0.53).
Is the Petrov's Defense: Classical Attack, Jaenisch Variation a good opening?
Stockfish rates the position at +0.40: white is slightly better. Evaluations this early in the game are small, so practical results depend far more on knowing the plans and typical structures than on the engine's number.
What is the ECO code of the Petrov's Defense: Classical Attack, Jaenisch Variation?
C42. ECO codes classify chess openings from A00 to E99; C is the volume for open games and the French Defense.

Opening names from the Lichess opening book (CC0). Pieces by Colin M.L. Burnett (GPLv2+).