Petrov's Defence

Petrov's Defence

a b c d e f g h 8 8 7 7 6 6 5 5 4 4 3 3 2 2 1 1 a b c d e f g h
Moves	1.e4 e5 2.Nf3 Nf6
ECO	C42–C43
Named after	Alexander Petrov
Parent	King's Knight Opening
Synonym(s)	Petroff Defence Petrov's Game Russian Defence Russian Game

Petrov's Defence or the Petrov Defence (also called Petroff Defence, Petrov's Game, Russian Defence, or Russian Game [Russian: Русская партия]) is a chess opening characterised by the following moves:

1. e4 e5

2. Nf3 Nf6

Though this symmetrical response has a long history, it was first popularised by Alexander Petrov, a Russian chess player in the mid-19th century. In recognition of the early investigations by the Russian masters Petrov and Carl Jaenisch, this opening is called the Russian Game in some countries.

The Petrov has a drawish reputation; however, it offers attacking opportunities for both sides, and a few lines are quite sharp. Often a trade occurs and Black, after gaining a tempo, has a well-placed knight. Pillsbury's game in 1895^[1] against Emanuel Lasker testifies to this. The Black counterattack in the centre also avoids the Ruy Lopez, Giuoco Piano (and other lines of the Italian Game), and the Scotch Game. The Petrov has been adopted by many of the world's leading players, including world champions Vasily Smyslov, Tigran Petrosian, Anatoly Karpov, and Vladimir Kramnik, along with grandmaster Fabiano Caruana and others.

The Encyclopaedia of Chess Openings codes for Petrov's Defence are C43 (for 3.d4) and C42 (for all other lines).^[2]

White's two main choices for move three that lead to independent lines, 3.Nxe5 (the Classical Variation, the most common move) and 3.d4 (the Steinitz Variation). 3.Nxe5 is more popular but they often lead to similar positions and "there is no clear reason to prefer one move over the other".^[3]

3.Nc3 may transpose to the Four Knights Game. 3.Bc4 may lead to the Boden–Kieseritzky Gambit or transpose to the Two Knights Defence or Bishop's Opening. Occasionally seen is the quiet 3.d3.

After 3.Nxe5, the Classical Variation, the standard reply for Black is 3...d6. Play usually continues 4.Nf3 Nxe4, after which several moves are commonly played.

This is the most common line and typically most often continues 5...d5 6.Bd3. The position is similar to an Exchange French in which Black has played the extra move ...Nf6–e4, though this extra move is not necessarily to Black's advantage. White will try to drive Black's advanced knight from e4 with moves like c4 and Re1. In practice White is usually able to achieve this, but at some structural cost such as having to play c4, which balances out.^[4]

A completely different approach is to meet 4...Nxe4 with 5.Nc3 Nxc3 6.dxc3 with rapid development and queenside castling. For instance, White can plan a quick Be3, Qd2, and 0-0-0, and play for a kingside attack, trusting that the doubled c-pawns will help protect the king, and that a strong initiative and attacking potential will offset the longterm disadvantage of having doubled pawns. In the 5.Nc3 line, Black must avoid 5...Bf5?? 6.Qe2! which wins a piece due to the pin (if 6...Qe7 7.Nd5, forcing 7...Qd7 because of the threat to the c7-pawn; then 8.d3 wins the piece). Viswanathan Anand resigned after only six moves after falling for this against Alonso Zapata at Biel in 1988.^[5]

White can also force simplification with Lasker's 5.Qe2 Qe7 6.d3 Nf6. This is generally only good enough for a draw, which Black should be satisfied with.

• 5.d3 is the French Attack, a quieter line.
• 5.c4 is the Kaufmann Attack, also explored by Keres.
• 5.Bd3 is the Millennium Attack.

These lines are all relatively uncommon today.

This risky line was labelled "speculative but entertaining" by Nick de Firmian^[6]. He evaluates the position in Veselin Topalov–Vladimir Kramnik, Linares 1999 as offering chances for both sides after 4...Kxf7 5.Nc3 c5!? 6.Bc4+ Be6 7.Bxe6+ Kxe6 8.d4 Kf7 9.dxc5 Nc6.^[7]

Though this move was labelled "ineffective" by de Firmian, it is occasionally seen at grandmaster level. US master Andrew Karklins has experimented with 4.Nd3!?, now called the Karklins–Martinovsky Variation. This was played in the World Chess Championship 2018 between Magnus Carlsen and Fabiano Caruana.^[8]

3...Nxe4, the Damiano Variation, has traditionally been regarded as an error, though it has occasionally been seen in recent grandmaster play. Black must play accurately to avoid a serious disadvantage. White usually plays 4.Qe2. Black must avoid:

• 4...Nf6??, as 5.Nc6+ wins the queen.
• 4...d5?, as 5.d3 Qe7 6.dxe4 Qxe5 7.exd5 loses a pawn.
• 4...d6?, as 5.Nxf7! Kxf7 6.Qxe4 leaves Black without castling rights and down a pawn.

Best is 4...Qe7 5.Qxe4 d6 6.d4 dxe5 7.dxe5 Nc6, and after 8.Nc3 Qxe5 9.Qxe5+ Nxe5 10.Nb5 (or 10.Bf4) White has the advantage.^[9][10]

3... Nc6?!, recently dubbed the Stafford Gambit, is considered dubious, but it sets a number of traps. It was advocated by Eric Rosen in the early 2020s and became popular in online games. After 4.Nxc6 dxc6, White wins a pawn but must play carefully. After 5.e5 (5.d3 is better) Ne4 6.d3?? (White should play 6.Nc3, 6.d4, or 6.Qe2) 6...Bc5! and White resigned in Lowens–Stafford, US correspondence game 1950.^[11][12] After 1.e4 e5 2.Nf3 Nf6 3.Nxe5 Nc6 4.Nxc6 dxc6 5.d3 Bc5, White must avoid the Légal Trap 6.Bg5?? Nxe4!, and if 7.Bxd8 (relatively best but still losing is 7.Be3) 7...Bxf2+ 8. Ke2 Bg4#. Instead White should play 6.Be2 Bc5 7.c3! with d3–d4 to follow, and Black has insufficient compensation for the pawn, though White must still play carefully.^[13]

• 3...Qe7?! is inferior, as 4.d4 d6 5.Nf3 Qxe4+ 6.Be2 gives White a large lead in development.

This move was preferred by Wilhelm Steinitz, the namesake, although it was known earlier. Black can capture either pawn. Also possible is 3...d6, transposing into the Philidor Defence.

A long and complicated tactical sequence which has frequently been seen in master games is 3...Nxe4 4.Bd3 d5 5.Nxe5 Bd6 6.0-0 0-0 7.c4 Bxe5 8.dxe5 Nc6 9.cxd5 Qxd5 10.Qc2 Nb4 11.Bxe4 Nxc2 12.Bxd5 Bf5 13.g4 Bxg4 14.Be4 Nxa1 15.Bf4 f5 16.Bd5+ Kh8 17.Rc1 c6 18.Bg2 Rfd8 19.Nd2 (diagram) and White has the slightly better endgame after either 19...Rxd2 20.Bxd2 Rd8 21.Bc3 Rd1+ 22.Rxd1 Bxd1 or 19...h6 20.h4.^[14][15]

Alternatives to the sequence include 5...Nd7, 5.dxe5, 4...Nc6, 4.dxe5, and 4.Nxe5, which typically transposes to the main line of the Classical Variation.

After 3...exd4, the usual continuation is 4.e5 Ne4 (4...Qe7?! 5.Be2 is better for White) 5.Qxd4 d5 6.exd6 Nxd6, followed by 7.Nc3 Nc6 8.Qf4 or 7.Bd3 Nc6 8.Qf4. After the other capture, 3...Nxe4, 4.Bd3 d5 (4...Nc6!? 5.Bxe4 d5, intending 6.Bd3 e4, is also possible) 5.Nxe5, when either 5...Nd7 or 5...Bd6 gives roughly equal chances.

The alternative 4.Bc4 transposes into the Urusov Gambit.

• 3...d5 usually ends up transposing to one of the above lines.
• 3...d6 transposes to Philidor's Defence.

3.Bc4 is less common than the alternatives but is still seen.

Another possibility is 3.Bc4 Nxe4 4.Nc3, the Boden–Kieseritzky Gambit. It is not considered wholly sound, since Black has several viable options. Black can accept the gambit with 4...Nxc3 5.dxc3 f6, but must play carefully after 6.0-0 (for example 6...Bc5?? 7.Nxe5! is disastrous; 6...d6 and 6...Nc6 are good).

Another more aggressive try is 6.Nh4, where White goes for a quick assault on Black's king, but Black can maintain a small advantage if he plays cautiously via 6...g6 7.f4 Qe7 8.f5 Qg7 9.Qg4 Kd8. Another possibility is returning the gambit pawn with 4...Nxc3 5.dxc3 c6 6.Nxe5 d5, which equalises.

A third possibility is transposing to the Italian Four Knights Game with 4...Nc6, and if 5.Nxe4, 5...d5. If 5.Bxf7+?, then 5...Kxf7 6.Nxe4 d5 gives Black the bishop pair and control of the centre. If 5.0-0, Black plays 5...Nxc3 6.dxc3 and now Black can play 6...Qe7!, after which Bobby Fischer wrote that "White has no compensation for the Pawn",^[16] or 6...f6 transposing to the main line of the Boden–Kieseritzky. Black also has lines beginning 6...Be7 and 6...h6.

• 3...Nxe4 4.d3 typically continues 4...Nf6 5.Nxe5 d5 6.Bb3 Bd6 7.d4 0-0 8.0-0 c5.
• 3...Nc6 transposes to the Two Knights Defence.

3.Nc3 is the Three Knights Game of Petrov's Defence. It is often played by White in order to avoid lines unique to the Petrov, as 3...Nc6, which transposes to the Four Knights Game, is Black's most common and best regarded response. It can also be reached via 2.Nc3 Nf6 3.Nf3 (the Vienna Game). The main alternative is 3...Bb4, which remains the Three Knights Game proper.

• List of chess openings
• List of chess openings named after people

• Forintos, Győző; Haag, Ervin (1983). Petroff's Defence. Batsford. ISBN 0-7134-3202-0.
• Janjgava, Lasha (2001). The Petroff. Gambit Publications. ISBN 1-901983-46-3.
• Kotronias, Vassilios; Tzermiadianos, Andreas (2005). Beating The Petroff. Batsford. ISBN 978-0-7134-8919-4.
• Raetsky, Alexander; Chetverik, Maxim (2005). Petroff Defence. Everyman Chess. ISBN 1-85744-378-0.
• Sakaev, Konstantin (2011). The Petroff: An Expert Repertoire for Black. Chess Stars. ISBN 978 954 8782 84-5.
• Yusupov, Artur (1999). The Petroff Defence. Edition Olms. ISBN 3-283-00400-5.

• "Petrov Defense (C42)". Chessgames.com. Retrieved 2007-04-26.
• Petrov's Defence Video and explanation
• Petrov's defence (C42) – 365Chess.com ECO Games
• Gary Lane on the Cochrane Gambit
• Cochrane Gambit theory