Classical Variation, Burn Variation, Main Line

After 4...dxe4 5. Nxe4 Be7 6. Bxf6 Bxf6 7. Nf3, Black plays 7...O-O rather than the alternative 7...Nd7. It is a Rubinstein-type position in which Black holds the two bishops. The center has been opened, leaving the d- and e-files half-open. White keeps a pawn on d4 and a centralized knight on e4, while Black's e6 pawn shields a compact kingside. Castling first puts the king to safety and leaves the queen's knight's development open. The bishop on f6 bears down on d4, so White has to decide how to meet that pressure on the eighth move.

8. c3 and 8. Bd3 are played almost equally often. The first shores up d4, and the second develops toward the kingside, where Black has castled. Next in frequency is 8. Nxf6+, which trades the knight for the f6-bishop. That removes Black's bishop pair and leaves a simpler, more symmetrical game. The engine prefers queen moves such as 8. Qd2, 8. Qd3 and 8. Qe2, and gives White a slight edge. White scores well in Lichess games, with draws uncommon. The best results have come after 8. Bd3, and 8. Nxf6+ has done least well for White.