Two Knights Attack

The Two Knights Attack, sometimes called the Two Knights Variation, arises after 1. e4 c6 2. Nc3 d5 3. Nf3 and can also be reached by 2. Nf3 d5 3. Nc3. Instead of the usual 2. d4, White brings out both knights and keeps the d-pawn uncommitted, so that it can later go to d3 or d4 depending on how Black arranges the pieces. Bobby Fischer used it as a young player, and although it has since lost ground at higher levels, it remains frequently reached in online play. ECO files it under B10, with 3...Bg4 given its own code, B11.

The most common reply is 3...dxe4 4. Nxe4, after which Black can try to play as in the Classical Variation, but the knight on f3 changes the picture. After 4...Bf5 5. Ng3 Bg6?! 6. h4 h6 7. Ne5 Bh7 8. Qh5 g6, forced, 9. Bc4 e6 10. Qe2, White stands much better, and 10...Qe7 is the only good defense. Lasker–Radsheer, 1908, and Alekhine–Bruce, 1938, ended quickly when Black instead played 10...Bg7 and 10...Nf6, respectively, both met by 11. Nxf7. Safer approaches include 4...Nd7 or, after 4...Bf5 5. Ng3, the move 5...Bg4.

The Mindeno Variation, 3...Bg4, is regarded as the most logical answer and is the second most popular choice; in the database it scores better for Black than the other main replies. The pin targets the knight that is supporting White's flexible setup. After 4. h3 Bxf3 5. Qxf3, White has the bishop pair and Black chooses between 5...e6 and 5...Nf6, aiming for a sound structure. Keeping the bishop with 4...Bh5 is possible but demands accuracy. In Noteboom–Mindeno, 1927, play went 5. exd5 cxd5 6. g4 Bg6 7. Ne5 a6? 8. h4 d4 9. h5 dxc3 10. hxg6 cxd2+ 11. Qxd2 Qxd2+ 12. Bxd2, and Black could not avoid losing material; 7...Nc6 was required.

The third common choice, 3...d4, gains space at once by attacking the knight on c3 and leads to a closed center. Engines rate the starting position as roughly balanced and list 3...dxe4, 3...Bg4 and 3...g6 as their preferred moves, while practical results are fairly close, with White slightly ahead.