Chessy
Petrov's Defense: Three Knights Game with Bb4 — Playing as White
After 1.e4 e5 2.Nf3 Nf6 3.Nc3 Bb4, Black pins your knight and threatens to double your pawns on the queenside. You have 4.Nxe5 — grabbing the pawn and calling Black's bluff. This page is about the position after that capture, with Black to move. The drill below puts you on the White side of a sharp, semi-open fight where one accurate move can give you a lasting edge. Let's look at what the statistics and the engine say about your best path forward.
Play the Petrov's Defense: Three Knights Game: Bb4 against the engine
Free, no signup — you play white, the engine adapts to your level.
Jump into the interactive drill below and practise meeting each of Black's replies — from the punishing 5...Nxe4 to the solid 5...Bxc3. The adapting engine will
Create a free account →The Critical Moment: Black's Decision
The pin 3...Bb4 puts immediate pressure on your knight at c3, and your reply 4.Nxe5 has created a tense trade-off. Black now has several ways to continue, and the statistics from over 462,000 games show just how much your results depend on which one they choose. The overall picture is close — White wins 47.2%, Black wins 48.7%, with just 4.1% draws — but that headline number hides big swings depending on Black's move. Your job is to know which replies to welcome and which to be wary of.
The Engine's Recommendation: Castle Immediately
Stockfish rates this position +0.43, a small but clear edge for White. That means you are slightly better here. The engine's best move is 5.O-O, getting your king to safety and bringing your rook toward the centre. After 5...Nd3 6.Bxc3 dxc3, you've traded your pinned knight for Black's powerful bishop and White's position is healthy. Castling is a practical, principled choice — it deals with the threat of ...Bxc3 (doubling your c-pawns) by making that trade less dangerous, since your king is already tucked away.
The Numbers on Black's Most Popular Replies
Let's look at what Black actually plays and how you fare against each one. - 5...Bxc3 (271,586 games — the overwhelming favourite): Black takes the knight immediately. White scores 48.1% here. White recaptures with the b-pawn and gets the bishop pair and central control. - 5...Qe7 (59,721 games): A tricky move attacking your knight on e5. White scores only 42.0% here — the worst outcome of the major lines. - 5...O-O (52,430 games): Black castles too. White scores 42.9% — still below your average. - 5...d6 (46,575 games): Black kicks your knight. White scores 50.1% here, your best result among the common replies. - 5...Nc6 (23,900 games): A known mistake. White scores 48.5%. - 5...Nxe4 (3,896 games): Another mistake. White's score jumps to 68.0% — your best overall.
Punishing Black's Biggest Mistakes
The engine identifies two clear errors Black can make in this position, and both are instructive. 5...Nc6 is a mistake that costs Black roughly 1.2 pawns. White's best was 5.O-O — meaning Black should have castled instead. After 5...Nc6, you can safely retreat your knight and maintain your extra pawn with good development. Even stronger is 5...Nxe4, which loses about 1.8 pawns. Again, the better move was 5.O-O. When Black grabs back on e4 with the knight, you have powerful replies — your knight on e5 is still alive, and Black's king is stuck in the centre. The 68.0% White win rate after Nxe4 shows just how punishing this mistake can be. The pattern is clear: Black's safest path is to keep the position closed or castle quickly; the most dangerous mistakes come when they lash out without first securing their king.
Results across 462,177 Lichess games
| Most-played continuation | Games | White wins |
|---|---|---|
| Bxc3 | 271,586 | 48.1% |
| Qe7 | 59,721 | 42.0% |
| O-O | 52,430 | 42.9% |
| d6 | 46,575 | 50.1% |
| Nc6 | 23,900 | 48.5% |
| Nxe4 | 3,896 | 68.0% |
Frequently asked questions
Should I play 4.Nxe5 or 4.Bb5 in the Three Knights Game?
After 1.e4 e5 2.Nf3 Nf6 3.Nc3 Bb4, the move 4.Nxe5 is the most aggressive — you win a pawn immediately and challenge Black's pin. The other main option, 4.Bb5, develops a piece instead. The position after 4.Nxe5 is well-played, with over 462,000 games in the database, and Stockfish favours it at +0.43 for White.
What should I do if Black plays 5...Bxc3?
That's Black's most common reply by far, played in over 271,000 games. You recapture with the b-pawn: 6.bxc3. White scores 48.1% from here. You get the bishop pair and a central pawn majority, while Black's knight on f6 still needs to develop. Your king is safe on g1 after castling, and your pawn structure is solid.
Is 5...d6 a good move for Black?
Statistically, 5...d6 is the reply that gives White the best results — White scores 50.1% after it, slightly above your average in this line. Black attacks your knight on e5, but after you retreat it, you simply keep your extra pawn and continue development. The engine also prefers 5.O-O in this position.
Why is 5...Nxe4 considered a mistake for Black?
The engine penalises 5...Nxe4 by about 1.8 pawns — it's a serious error. Black grabs material in the centre but leaves their king exposed and your knight on e5 still active. The statistics confirm this: White wins 68.0% of games after 5...Nxe4, your best score against any Black reply. Castling (5.O-O) was the correct move instead.
How many games feature the Petrov's Defense: Three Knights Game: Bb4?
Over 462K Lichess games have reached the Petrov's Defense: Three Knights Game: Bb4 position. White wins 47.2%, Black wins 48.7%, with 4.1% draws — based on real rated games.