Petrov Defense

12. Four Knights Transposition 3.Nc3 Nc6

If White avoids Petrov theory with 3.Nc3, Black happily transposes into the Four Knights Game with 3...Nc6. In the Spanish Four Knights with 4.Bb5 Bb4 5.O-O O-O 6.d3 d6 7.Bg5, Black trades on c3 and maneuvers Nd8-e6 for ironclad control.

1.e4 e5 2.Nf3 Nf6 3.Nc3 Nc6 4.Bb5 Bb4 5.O-O O-O 6.d3 d6 7.Bg5 Bxc3 8.bxc3 Qe7 9.Re1 Nd8 10.d4 Ne6 11.Bc1 c5 12.Bf1 Rd8

Move by move

  1. 1.e4 – White opens with the classical 1.e4, controlling d5 and f5 and freeing diagonals for both the f1 bishop and the queen to begin an open game.
  2. 1...e5 – You respond symmetrically with 1...e5: staking your claim in the center, preventing d4, and opening paths for your own pieces.
  3. 2.Nf3 – White develops the king's knight toward the center, attacking your e5 pawn and preparing rapid kingside castling in two moves.
  4. 2...Nf6 – The Petrov Defense! With 2...Nf6 you disregard White's attack on e5 and launch a symmetrical counterstrike against their e4 pawn.
  5. 3.Nc3 – White sidesteps theoretical Petrov lines with 3.Nc3, inviting a transposition into the solid and balanced Four Knights Game.
  6. 3...Nc6 – You mirror with 3...Nc6: completing natural Four Knights development and entering a realm of rock-solid positional equality.
  7. 4.Bb5 – The Spanish Four Knights: White develops the bishop to b5 pinning your knight and applying positional pressure against the e5 pawn.
  8. 4...Bb4 – You reply symmetrically with 4...Bb4: pinning the c3 knight and maintaining a flawless dynamic balance across the whole board.
  9. 5.O-O – White castles kingside in the Spanish Four Knights, safeguarding their king and stepping into a complex maneuvering struggle.
  10. 5...O-O – You complete kingside castling in kind: both monarchs are safe and the game enters a purely strategic, positional phase.
  11. 6.d3 – White solidifies their center with 6.d3, opening the diagonal for the c1 bishop and wisely avoiding premature line clearances.
  12. 6...d6 – You respond with the sturdy 6...d6 defending e5 and clearing a natural exit diagonal for your light-squared bishop in turn.
  13. 7.Bg5 – White develops the bishop to g5 to pin your f6 knight and attempt to generate uncomfortable pressure against your kingside.
  14. 7...Bxc3 – You trade on c3 with 7...Bxc3: damaging White's pawn structure with doubled pawns and removing the key defender of the e4 square.
  15. 8.bxc3 – White recaptures toward the center with the b-pawn, accepting doubled pawns in exchange for the nominal bishop pair in the position.
  16. 8...Qe7 – Classical maneuver with 8...Qe7: stepping out of potential pins, connecting the rooks, and preparing the knight maneuver.
  17. 9.Re1 – White's rook occupies the e-file, preparing the central d4 pawn push to open up diagonals for their bishop pair in due course.
  18. 9...Nd8 – A masterful thematic maneuver: you reroute the knight toward d8 to reposition it on the formidable e6 square to nullify Bg5.
  19. 10.d4 – White pushes d4 to blow open the center and activate their bishops, but your setup is compact and ready to repel the attack.
  20. 10...Ne6 – The knight lands triumphantly on e6 attacking White's g5 bishop and exerting magnificent control over key central squares on d4 and f4.
  21. 11.Bc1 – White's bishop is forced to beat a retreat to c1, acknowledging the failure of the pin and conceding valuable operational tempi.
  22. 11...c5 – You break in the center with the timely 11...c5! Fixing White's pawn center, opening room for your queen, and seizing control.
  23. 12.Bf1 – White retreats the bishop to f1 to reorganize their defense and protect their e4 pawn against upcoming central breakthroughs.
  24. 12...Rd8 – You centralize the rook on d8 along the file: coordinating all your pieces and achieving complete, comfortable positional parity.

How to exploit the position

Complete symmetrical Four Knights development with 3...Nc6

Master tips

Transposing into the Four Knights is one of Black's safest options

The Nd8-e6 maneuver is the trademark blueprint to defuse White's Bg5 pin

Model games