Nimzowitsch Defense

The Nimzowitsch Defense, also spelled Nimzovich, is named after Aron Nimzowitsch and classified under B00. It is a hypermodern opening. Black lets White build a broad pawn center, intending to restrain it and then attack it with pawn breaks or with pressure on its defenders. The knight on c6 eyes d4 but does not prevent 2. d4, because the white queen also covers that square. It is seen far less often than the main defenses to 1. e4, yet a large number of online games reach it. The engine gives White a slight edge, and results are close to even.

Against 2. d4 Black has three main choices. 2...d5, the Scandinavian Variation, was Nimzowitsch's own preference. After 3. e5 Bf5 Black follows with ...e6, getting a French-type chain with the light-squared bishop already outside it, and later hits the center with ...f6 and ...c5. After 3. exd5 Qxd5, the natural 4. Nc3 drops the d4 pawn, so White usually plays 4. Nf3, and Black contests the center with 4...Bg4 or 4...e5. The line 3. Nc3 dxe4 4. d5 Ne5 continues with 5. Qd4 or 5. Bf4 Ng6 6. Bg3. The Kennedy Variation, 2...e5, is a solid line favored by Tony Miles. Here 3. Nf3 transposes to the Scotch Game, 3. d5 Nce7 aims for ...Ng6, and after 3. dxe5 Nxe5 White chooses between the quiet 4. Nf3 and the sharper 4. f4. The Mikenas Variation, 2...d6, hands White the initiative and allows 3. c4, 3. d5, or simple development.

The most common reply is 2. Nf3, the Declined Variation. It avoids the independent lines after 2. d4 and offers a transposition to the open games after 2...e5. Black players who want to stay in Nimzowitsch territory often choose 2...d6, the Williams Variation, which is sound but can turn into a poor version of the Pirc. After 3. d4 Bg4 4. Bb5 a6 5. Bxc6+ the position is about level. The sharper 4. d5 Ne5 5. Nxe5, the Keene Attack, gives up the queen and regains it by force. Other options include the dubious 2...f5, the Colorado Countergambit, which Doug Root and Olli Salmensuu have played, and 2...e6, the Franco-Nimzowitsch, a French in which ...c5 is unavailable. After 2...Nf6 3. e5, Black can try the eccentric El Columpio, 3...Ng4, devised by Marc Narciso Dublan.

White has other second moves. 2. Nc3 allows the French Connection with 2...e6, or the Breyer Variation with 2...Nf6 3. d4 e5. The Pseudo-Spanish Variation, 2. Bb5, invites 2...e5 3. Nc3 with a transposition to the Ruy Lopez. Until ...e5 is played, however, the bishop has little to aim at, and Black can avoid the transposition with 2...d5 or 2...Nf6.