5. Open Variation with 9.Nbd2 (Dilworth Antidote)
By playing 9.Nbd2 at once, White forces Black to decide immediately the fate of the knight on e4, reducing the tactical chances of Black's counterattack.
1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Nxe4 6.d4 b5 7.Bb3 d5 8.dxe5 Be6 9.Nbd2 Nc5 10.c3 d4 11.Bxe6 Nxe6 12.cxd4 Ncxd4
Move by move
- 1.e4 – White takes the centre and opens the diagonals for the queen and the f1-bishop. In the Ruy Lopez this pawn will often be at the heart of the fight: Black will attack it with ...Nf6 and, in the Open Variation, will even capture it with ...Nxe4.
- 1...e5 – Black answers symmetrically: it contests d4 and f4, prevents e4-e5 and frees the f8-bishop. From here White will build the whole Ruy Lopez on pressure against this pawn.
- 2.Nf3 – Develops the knight with a direct attack on the e5 pawn, which now has to be defended. The knight also prepares kingside castling and supports a future d2-d4 push.
- 2...Nc6 – Defends e5 while developing a piece and controlling d4. This very knight, the only defender of e5, will be the target of White's next move.
- 3.Bb5 – The Ruy Lopez: the bishop attacks the c6-knight, the defender of e5. There is no immediate threat yet (Bxc6 dxc6 Nxe5 Qd4 regains the pawn), but the pressure on c6 will last throughout the opening.
- 3...a6 – Morphy's move: it asks the bishop to decide right away. After 4.Ba4 Black can break the pin with ...b5 whenever it likes; after 4.Bxc6 it gets the bishop pair.
- 4.Ba4 – The bishop retreats but keeps the pressure on c6: the threat of Bxc6 followed by Nxe5 will come back once White has castled. Black can break the diagonal with ...b5 whenever it wants.
- 4...Nf6 – Develops the knight attacking e4. This is the main move: it leads to the Closed Ruy Lopez with ...Be7 or to the Open Variation with ...Nxe4.
- 5.O-O – Castles without defending e4: if Black takes it with ...Nxe4, White regains it with Re1 or d4, exploiting the black king still in the centre.
- 5...Nxe4 – The Open Variation: Black takes e4 and activates the knight. The pawn will be returned, but Black gets free, active play.
- 6.d4 – Opens the centre while the black king is still on e8: White threatens d5 or dxe5 and the e-file becomes dangerous for Black. This is the strongest reply to the Open Variation.
- 6...b5 – Moves the a4-bishop away before ...d5 is pushed: that way the c6-knight is no longer pinned and Black can support the e4-knight with the pawn. It also gains space on the queenside.
- 7.Bb3 – The bishop goes to the a2-g8 diagonal, where it will attack d5 after ...d5 and eye f7.
- 7...d5 – Supports the e4-knight and closes the diagonal of the b3-bishop. Black gives the pawn back: after dxe5 material is level, but its pieces are active.
- 8.dxe5 – Regains the pawn. The e5 pawn gains space and takes the d6 and f6 squares away from Black's pieces: it will be White's strong point throughout the variation.
- 8...Be6 – Develops the bishop, defending d5, which is attacked by the b3-bishop. It is the most solid move: the e6-bishop also holds d5 against future pushes.
- 9.Nbd2 – Challenges the e4-knight at once without playing c3 first. This way White avoids the Dilworth Attack (9.c3 Bc5 10.Nbd2 O-O 11.Bc2 Nxf2), which relies on the bishop on c5 against f2.
- 9...Nc5 – The knight retreats to c5 attacking the b3-bishop. Black can then choose between ...d4, to free its game, and ...Nxb3.
- 10.c3 – Gives the bishop the retreat to c2 and controls d4. It also prepares Nd4 to exchange the e6-bishop.
- 10...d4 – Active push: Black opens the diagonal of the e6-bishop against b3 and threatens ...dxc3 to weaken White in the centre.
- 11.Bxe6 – Exchanges the bishops before ...Bxb3 or ...dxc3 change the game: White eliminates the bishop that controlled d5 and c4.
- 11...Nxe6 – Recaptures with the c5-knight, which now controls d4 and f4. Taking with ...fxe6 would have weakened the kingside structure.
- 12.cxd4 – Eliminates the d4 pawn and opens the c-file, where the white rook can attack the c7 pawn.
- 12...Ncxd4 – The c6-knight recaptures and settles on d4, in the centre. Black has two active knights, but the f8-bishop is not yet developed and the king is still on e8.
How to exploit the position
Black has well-centralised knights but is behind in development: king on e8 and bishop f8 still at home. White has the e5 pawn and the open c-file.
- Bring the d2-knight to e4: from there it aims at d6, c5 and f6 and hampers Black's development.
- Develop quickly with Be3 and Rc1: the rook on the c-file attacks c7 until the black king has castled.
- Push a4 to hit b5 and open the a-file against the a6 pawn.
- Exchanging on d4 with Nxd4 simplifies, but only if White can then occupy the centre with Ne4 or Qf3.
Master tips
Forcing clarification in the centre
After 9.Nbd2 Nc5 10.c3 d4 11.Bxe6 Nxe6 12.cxd4 Ncxd4 Black has two central knights, but its king is still on e8 and the f8-bishop is undeveloped.