Two Knights Defense, Max Lange Attack

The Max Lange Attack, named after the German master Max Lange, who proposed it in 1854, arises after Black meets the Open Variation with 5...Bc5 and White pushes 6. e5, hitting the f6-knight. The position can also be reached from the Scotch Gambit, Bishop's Opening, Giuoco Piano and other move orders. White is temporarily a pawn down but aims to exploit the e-file and the pin potential against Black's uncastled king. In online games White scores well, and the engine gives White a slight edge.

The classical reply is 6...d5 7. exf6 dxc4 8. Re1+ Be6 9. Ng5 Qd5 10. Nc3 Qf5. Black must avoid 9...Qxf6, a well-known blunder that loses to a queen check and fork. After 10...Qf5, 11. Nce4 allows the Rubinstein Variation, 11...Bf8, or 11...O-O-O with complex play, while 11. g4 Qg6 12. Nce4 Bb6 13. f4 O-O-O is the Berger Variation. Black can deviate earlier with 9...g6, the Loman Defense. White's alternatives include 7. Bb5 and 8. fxg7 Rg8 9. Bg5. The knight sorties 6...Ng4, frequently met by 7. c3 (Krause Variation), and 6...Ne4 are also common online.