Petrov Defense: Complete Guide

The Petrov Defense (Russian Game, sometimes spelled Petroff) is the reply 1. e4 e5 2. Nf3 Nf6. Black does not guard the e5-pawn at all. The knight simply attacks e4 in return, so the position stays symmetrical and both sides have a pawn hanging. Among lichess players rated 1000 to 1600, roughly one player in nine answers 2. Nf3 this way, which makes it a minority choice that most club opponents have never studied from White's side.

This course plays the direct version. When White takes on e5, Black takes back on e4 at once with 3...Nxe4, and the game turns on one position: 4. Qe2, which White chooses in more than half of these games. The queen attacks the knight on e4 and stands behind White's own knight on the e-file, aimed at the black king. The right answer is 4...Qe7, mirroring the queen. After 5. Qxe4 d6 the white knight on e5 cannot move, because the moment it steps aside Black captures the white queen on e4 with check. Black wins the piece back and plays for more. From there the course teaches two middlegame plans: a pawn storm with ...g5, ...f5 and ...f4 that traps a bishop on g3, and a queenless ending where ...Bf5, long castling and a knight jump to b4 pick up White's extra pawn.

Play 1...e5 against 1. e4 and, when the king's knight comes to f3, bring your own knight to f6. What happens next is White's decision. At the 1000 to 1600 level about one White player in three takes on e5, and about the same number play 3. Nc3, which invites a Four Knights Game. Nearly one in five plays 3. Bc4, and 3. d3 and 3. d4 turn up in roughly one game in fourteen and one in twenty. The course answers every one of these moves, because in our own users' Petrov games White left the original course's lines in nearly two games out of three, mostly right there on move three.

After 3. Nxe5 Nxe4 the options narrow again. 4. Qe2 is the main test. 4. Qf3, 4. Bc4 and 4. d3 each appear in somewhere between one game in nine and one in fourteen, and 4. Nxf7, the greedy knight grab, turns up about once in thirty-five games. If you arrive through 2. Nc3 Nf6 3. Nf3 or 2. d3 Nf6 3. Nf3, the same chapters apply. White's other second moves (2. Bc4, 2. d4, 2. f4, 2. Qh5) usually take the game somewhere else, and the Open Game course covers them. One exception: 2. Bc4 Nf6 3. Nf3 lands straight in this course's 3. Bc4 lines.

If you are White, the soundest way to meet the Petrov is 3. Nxe5 d6 4. Nf3 Nxe4 5. d4, which keeps a small, safe edge for White. Against the immediate 3...Nxe4, 4. Qe2 is the right test. If Black retreats with 4...Nf6, 5. Nc6+ wins the queen. If Black finds 4...Qe7, take on e4 and give the pinned knight up with 5...d6 6. d4. After 6...dxe5 7. dxe5 Nc6, be careful with 8. Bf4, because the bishop can be trapped on g3 by ...g5, ...f5 and ...f4. At the 1000 to 1600 level, 8. Nc3 is the move Black handles worst. Against 3...Nc6, the Stafford Gambit, take the knight with 4. Nxc6 dxc6, then play 5. Nc3 Bc5 6. h3 to keep a knight off g4. Accepting the pawn this way leaves you clearly better.

Frank Marshall, Anatoly Karpov and Vladimir Kramnik all kept 2...Nf6 in their Black repertoires, and Fabiano Caruana relied on it against Magnus Carlsen in their 2018 title match. The name goes back further, to Alexander Petrov, a leading Russian player of the early 19th century who analysed the move together with Carl Jaenisch. Most databases file it as the Russian Game, and older English books spell it Petroff. Club games rarely look like those grandmaster ones. In our own users' games, Black answered 4. Qe2 with 4...Qe7 in only 46 of 242 tries, and closing that gap is what this course is built for.

What is the Petrov Defense in chess?

It is 1. e4 e5 2. Nf3 Nf6, Black's counterattack on e4 instead of defending e5. Most databases file it under the Russian Game. At club level only about one player in nine chooses it after 2. Nf3, so opponents rarely know it well. This course follows 3. Nxe5 with the direct 3...Nxe4 and answers every other third move White plays.

What is the Petrov trap with 4. Qe2?

After 1. e4 e5 2. Nf3 Nf6 3. Nxe5 Nxe4 4. Qe2, the queen attacks the knight and lines up with the black king behind White's knight on e5. The obvious retreat, 4...Nf6, loses: 5. Nc6+ uncovers check from the queen and attacks the black queen on d8 at the same time. Black's correct reply is 4...Qe7. After 5. Qxe4 d6 White's knight is stuck, because moving it allows ...Qxe4+. In our own users' games, fewer than one player in five found 4...Qe7, which is exactly why this course starts there.

How do you play against the Petrov Defense?

The most reliable approach is 3. Nxe5 d6 4. Nf3 Nxe4 5. d4, which gives White a small edge at almost no risk. If Black plays 3...Nxe4 immediately, 4. Qe2 sets the trap. After the correct 4...Qe7, capture on e4 and play 6. d4, but avoid putting a bishop on f4 where ...g5 and ...f5 can trap it. Players who want to avoid theory can choose 3. Nc3 for a Four Knights Game instead.

Can a beginner learn the Petrov quickly?

Most of it, yes, because the course keeps returning to four ideas: freeze the knight on e5, win the e5-pawn back, castle long, and bury a bishop that lands on f4 with ...g5 and ...f5. Learn one move before anything else, 4...Qe7 against 4. Qe2. In our own users' games only 46 of 242 players found it, and those 4. Qe2 games scored just 26% for Black.

What if White does not take on e5?

That happens in about two games out of three at club level. Against 3. Nc3 the fork trick 4. Bc4 Nxe4 5. Nxe4 d5 wins the piece back. Against 3. Bc4 Black also captures on e4. Against 3. d4, take on e4 and follow with ...d5. Against 3. d3, develop with ...Nc6 and strike with ...d5. Each has its own line in the course.

Is the Stafford Gambit sound?

Not objectively. After 3. Nxe5 Nc6 4. Nxc6 dxc6 5. Nc3 Bc5 6. h3 White is clearly better. It still scores about 50% at club level because the natural White moves walk into traps against f2 and the king. The course teaches it as an optional chapter with six lines, including the honest line when White declines with 4. Nf3.