2Nf6

2...Nf6 denotes Black’s knight move to f6 on Black’s second move in certain e4-e5 openings. The most recognized instance is the sequence 1.e4 e5 2.Nf3 Nf6, which defines the Petrov Defense (also known as the Russian Defense). The move immediately challenges White’s central e4 pawn and supports swift development of the kingside knight.

Strategic ideas. Playing Nf6 aims for solid, symmetrical development and quick equalization rather than early tactical skirmishes. It discourages White from maintaining an overwhelming pawn center and invites a balanced middlegame where both sides have chances. White’s most common reply is 3.Nxe5, after which Black often plays 3...d6, and the game continues with 4.Nf3 or 4.d4 depending on the variation. Another viable approach for White is to avoid capture on e5 with 3.Nc3 or 3.Bc4, keeping tension in the center.

Variants and typical lines. If White plays 3.Nxe5 d6 4.Nf3 Nxe4, Black reaches a dynamic but relatively balanced position where pawn activity and piece play define the middlegame. The Petrov Defense encompasses multiple sub-variations and move orders, with players choosing lines that suit their strategic preferences—whether aiming for solid, drawish structures or more dynamic contest.

Evaluation and usage. The Petrov Defense has a long, continuous presence in chess literature and practice. It is valued for its solidity and for equalizing chances against White’s initial pawn duo, making it a standard tool at club and professional levels alike. While not as aggressively tested as some e4-e5 systems, it remains a reliable and flexible option in many repertoires.