The Dutch Defence is a chess opening characterised by the moves
1. d4 f5
Elias Stein (1748–1812), an Alsatian who settled in The Hague, recommended the defence as the best reply to 1.d4 in his 1789 book Nouvel essai sur le jeu des échecs, avec des réflexions militaires relatives à ce jeu.
Black's 1... f5 stakes a serious claim to the e4 square and looks towards an attack on White's kingside in the middlegame. However, it weakens Black's own kingside somewhat, and does nothing to contribute to Black's development. As of 2006, the Dutch is unpopular in top-level play. It has never been one of the main lines against 1.d4, though in the past a number of top players, including Alexander Alekhine, Bent Larsen, Paul Morphy and Miguel Najdorf, have used it with success. Perhaps its high-water mark occurred in 1951, when both world champion Mikhail Botvinnik and his challenger, David Bronstein, played it in their World Championship.
White most often fianchettoes his king's bishop with g3 and Bg2; White may play g3 on the second move, but more common is to play c4 first. Black also sometimes fianchettoes his king's bishop with ...g6 and ...Bg7 (the Leningrad Dutch), but may instead develop his bishop to Be7, d6 (after . . .d5), or b4 (the latter is most often seen if white plays c4 before castling). Play often runs 2.g3 Nf6 3.Bg2 e6 4.Nf3 (4.Nh3!? is also possible, intending Nf4-d3 to control the e5 square if Black plays the Stonewall Variation) Be7 5.0-0 0-0 6.c4 and now Black chooses between 6...d5 (the characteristic move of the Stonewall Variation), 6...d6, the Iljin-Zhenevsky System or Fluid System (less popular today), or Alekhine's move 6...Ne4!? retaining the option of moving the d-pawn either one or two squares.
White has various more aggressive alternatives to the standard 2.c4, including 2.Nc3 d5 3.Bg5; 2.Bg5 (hoping for the naive 2...h6 3.Bh4 g5 4.Bg3 (4.e4!? is also playable) f4? 5.e3 fxg3?? 6.Qh5#); and 2.e4!?, the Staunton Gambit, named after Howard Staunton, who introduced it in his match against Horwitz. The Staunton Gambit was once a feared attacking line, but it has been out of favor for over 80 years. Grandmaster Larry Christiansen and International Master Jeremy Silman have opined that it "offers White equality at best." Staunton also introduced a completely different gambit approach to the Dutch, 2.h3 followed by g4, in his 1847 treatise The Chess-Player's Handbook. Viktor Korchnoi, one of the world's leading players, introduced the line into tournament practice more than a century after Staunton's death in Korchnoi-Känel, Biel 1979. GM Christiansen later concluded, as Staunton had done over 140 years earlier, that Black could get a good game by declining the gambit with 2...Nf6 3.g4 d5!
The opening's attacking potential is shown in the Polish Immortal, in which Black sacrificed all of his minor pieces.