Queen's Knight Defense

The Queen's Knight Defense answers the King's Gambit with the most natural developing move, 2...Nc6, leaving the f4-pawn alone. The knight supports e5 in advance, so that a capture on e5 can be met by a recapture. The pawn is not actually in danger on the second move, because 3. fxe5 runs into 3...Qh4+, after which the queen goes on to take e4 with check. The move is far more popular in club and online games than in serious tournament play.

White's usual reply, chosen in the large majority of games, is 3. Nf3. It covers h4, removing the queen check, and so turns fxe5 into a real threat that Black has to address. Engines suggest 3...d5 4. exd5 Qxd5 5. Nc3 Qe6, opening the center while the queen stays on the e-file. Because White develops with gain of time against the queen in this line, it is usually thought to leave White a small edge, and practical players more often choose the Miles Defense, 3...f5, which counterattacks e4 at once. Black can also take the gambit pawn belatedly with 3...exf4, and after 4. d4 the game transposes to the MacLeod Defense.

The second most common reply, 3. Nc3, transposes to the Max Lange Defense of the Vienna Gambit, which reaches the same position through the move order 1. e4 e5 2. Nc3 Nc6 3. f4. Among the rarer choices, 3. Bc4 develops the bishop without first stopping the check on h4, and 3. fxe5 loses material to 3...Qh4+, though it still appears in a noticeable share of games.

Engines judge the position after 2...Nc6 as roughly balanced, with 3. Nf3 preferred and the quieter 3. Be2 and 3. d3 also among the top suggestions. In practice White scores somewhat better, and draws are very rare, reflecting the open, sharp positions typical of King's Gambit play at club level.