Reversed Nimzowitsch

The Reversed Nimzowitsch arises after 1. Nc3 e5. Black answers the queen's knight opening by occupying the center with the king's pawn. The name comes from the mirror relationship with the Nimzowitsch Defense, 1. e4 Nc6. Here the colors are swapped, so White plays the knight-first side of that defense with an extra tempo. Because the Nimzowitsch is a playable defense for Black, the same arrangement with a move in hand is considered sound for White. The engine rates the position as roughly balanced, and online results are close to even, with White marginally ahead.

The most frequent continuation by a wide margin is 2. e4, which transposes to the Vienna Game. For many 1. Nc3 players this is the intended destination, and the knight-first move order narrows Black's options compared with 1. e4. Players who want to stay outside standard king's pawn theory choose one of the other second moves.

The second most common reply is 2. Nf3, which attacks e5 and keeps the e-pawn back. After 2...Nc6 3. d4 the game becomes the Napoleon Attack. White opens the center much as in the Scotch Game, but the knight is already committed to c3 and the e-pawn has not moved. Black can instead offer a pawn with 2...Bc5, the Billockus-Johansen Gambit.

The line 2. d4 exd4 3. Qxd4 is the closest mirror of the Nimzowitsch. Black has not spent a move on ...d5, so 3...Nc6 can be played at once to gain time on the centralized queen. After 4. Qa4 the queen settles on the edge, and the position resembles a Scandinavian Defense with colors reversed and White a tempo up. Among the main second moves, 2. d4 gives White the best practical results.

The less common replies have their own names. 2. f4 strikes at e5 at once and is classified as the Bahr Gambit, a line grouped under From's Gambit in the Bird Opening. 2. a3 is the Battambang Variation.