The Four Knights Game: Bc4 — Black's Best Reply

After 4.Bc4 Nxe4 the engine evaluates the position at +0.00 — dead equal. That might not sound exciting, but remember: in a sharp opening like this, equality for the second player is a psychological win. You've taken a pawn and kept the position balanced. The real story shows up in the results: across nearly 2.7 million Lichess games, Black wins 57.5% of the time, while White wins just 38.7% (with only 3.9% draws). Those numbers tell you that White is far more likely to go wrong than Black. Your job is to know which of White's moves are dangerous, which are harmless, and which are outright blunders waiting to be punished.

White's best move is to recapture immediately with 5.Nxe4. The engine gives this the stamp of approval, and it's by far the most common reply in practice — played in nearly 2 million games. After 5.Nxe4 you continue with 5...d5, opening the centre and attacking the bishop on c4. White's best reply is 6.Bd3, defending the knight on e4, and after 6...dxe4 7.Bxe4 you reach a balanced position with opposite-coloured bishops already on the board. Black has easy development and no weaknesses. Even though White scores only 36.5% after 5.Nxe4 (meaning Black scores over 63%), the engine says the position is equal. In human play, Black's simple central break makes the position very comfortable to handle.

The most tempting mistake White can make — and it happens over 419,000 times in the database — is 5.Bxf7+?. This check looks aggressive, but it's a clear mistake that loses about 1.5 pawns. After 5...Kxf7, you've traded a bishop for a pawn, and Black's king is misplaced but safe. You follow up with natural developing moves, and the extra piece gives you a lasting advantage. The statistics bear this out: White scores 47.3% after Bxf7+, far below what you'd expect if the move were good. Recognise this pattern and grab the piece — it's the most common gift you'll receive in this line.

Two other popular replies are also subpar. The quiet 5.d3 (played over 118,000 games) is a mistake costing about 1.6 pawns. White drops the knight back, and you can simply retreat your knight to f6 or keep it on e4 with support — either way you're up a clean pawn with no compensation. White scores just 38.7% after this move. Castling with 5.O-O (nearly 87,000 games) is less damaging — an inaccuracy losing about half a pawn — but still leaves you with an edge. White scores 46.3% after O-O, which is below the typical White scoring average. The rarest of the common replies, 5.Nxe5 (only about 15,000 games), is a disaster for White: they score just 28.6%. After 5...Nxe5, your knight is centralised and you're still a pawn up.