The Nimzowitsch Defence is a somewhat unusual chess opening characterised by the moves: This opening is an example of a hypermodern opening in which Black invites White to occupy the of the board at an early stage with pawns. Black's intent is to block or otherwise restrain White's central pawns and, if allowed to do so by inaccurate play by White, eventually undermine the White pawn centre by well-timed pawn advances of their own or by attacking the white pieces defending the centre. World ChampionGarry Kasparov and GrandmasterRaymond Keene wrote that it "has never been fully accepted as a dependable opening. Nevertheless it is sound and offers the maverick spirit a great deal of foreign territory to explore." The Nimzowitsch is included under code B00 in the Encyclopaedia of Chess Openings.
Main line: 2.d4
White takes the initiative in the centre. Black's main continuations are 2...d5 or 2...e5.
2...d5
The line that Aron Nimzowitsch, the originator of the opening, usually preferred. Now White can choose among:
3.e5, which Black usually meets with 3...Bf5, followed by playing...e6 and later attacking White's central with moves such as...f6 and...c5.
3.exd5 Qxd5, followed by either 4.Nf3, seeking to gain time by attacking the queen with Nc3, but enabling Black to put pressure on White's centre with 4...Bg4 or 4...e5.
3.Nc3 dxe4 4.d5 Ne5, when White usually continues with 5.Qd4 or 5.Bf4 Ng6 6.Bg3.
2...e5
A line favoured by the late British grandmaster Tony Miles. White can transpose to the Scotch Game with 3.Nf3, or play 3.d5 Nce7, which gives White only a slight plus score in practice. Another approach is 3.dxe5 Nxe5, when White can seek a quiet advantage with 4.Nf3 or play the more aggressive thrust 4.f4.
2.Nf3
Shown by some databases to be the , 2.Nf3 is often played by White players not eager for a theoretical battle on their opponent's turf.
2...e5, transposing to a double king-pawn opening may be the best move, but is unlikely to appeal to the hard-core Nimzowitsch player.
The sharp 2...f5, the Colorado Gambit, although somewhat dubious, was played with some success by the AmericanInternational MasterDoug Root, and more recently by the Finnish International Master Olli Salmensuu and others. It may lead to wild complications, e.g. 3.exf5 d5 4.Nh4 e5!? 5. Qh5+ g6 6.fxg6 Nf6 7.g7+ Nxh5 8.gxh8=Q Qxh4 9.Qxh7 Nd4, when White is a rook up, but Black has a huge lead in and White's king is in jeopardy. Naiditsch–Doettling, Dortmund 2000, ended in a draw after further complications: 10.Qg6+ Kd8 11.d3 Nf4! 12.Qf7 Bb4+ 13.c3 Bg4! 14.Qg8+ Kd7 15.Qg7+ Kc6 16.g3 Nf3+ 17.Kd1 Nd4+ 18.Kd2 Nf3+ 19.Kd1 Nd4+. The British International Master Gary Lane advocates the more solid 4.d4 Bxf5 5.Bb5 Qd6 6.Ne5 Nf6 7.0-0 Nd7 8.Bxc6 bxc6 9.Qf3! Nxe5 10.Qxf5 Nf7 11.Bf4 Qd7 12.Qxd7+ Kxd7 13.Nd2 when Black's inferior pawn structure gave White a small advantage in Shaw–Salmensuu, European Team Championship, León 2001.
2...d6, the Williams Variation, is known to be a solid option for Black, but is less dynamic than the former options and can lead to an inferior version of the Pirc Defense. The main line continues 3.d4 Bg4, but 3...Nf6 is completely. The line usually continues 4.Bb5 a6 5.Bxc6+, leading to a fairly equal position, but a sharper try for white is 4.d5 Ne5 5.Nxe5!?, the Keene Attack, named after Raymond Keene, who played it in a 1964 game against E. Fielder. While this attack sacrifices the queen, Black can gain it back after 5...Bxd1 6.Bb5+ c6 7.dxc6 Qa5+ 8.Nc3 0-0-0 9.Nc4 Qc7 10.Nd5.
