Hungarian Opening

The Hungarian Opening, 1. g3, is also called Benko's Opening or the King's Fianchetto Opening and is classified under ECO A00. The pawn move has no direct effect on the center. Its purpose is to clear g2 for the bishop, which from the long diagonal bears on the central squares and on Black's queenside. This follows the hypermodern view that the center can be controlled at a distance by pieces, leaving the opponent's advanced pawns to become targets. Fianchettoing also lets White castle kingside very quickly.

Because it commits White to so little, 1. g3 is highly transpositional and can lead into many mainstream openings. A common plan is the King's Indian Attack, also known as the Barcza System, with the bishop on g2, a knight on f3 and the king castled short. White's later central pawn moves then decide which structure the game takes on, and some named branches, such as the Catalan and Slav Formations, are defined by the setup Black adopts against the fianchetto.

Black's most frequent replies, 1...d5 and 1...e5, occupy the center with a pawn and take space. After 1...d5 2. Bg2, Black can support the d-pawn with 2...c6 (the Slav Formation) or 2...e6 (the Catalan Formation), or play 2...c5, the Reversed Modern Defense. After 2...e5, the Bücker Gambit 3. b4 offers a wing pawn. Against 1...e5, the reply 2. Nf3 attacks the pawn and is called the Reversed Alekhine; if Black pushes past with 2...e4, then 3. Nh4 gives the Reversed Norwegian Defense. Other sound choices include 1...Nf6 (the Indian Defense), 1...c5 (the Sicilian Invitation), 1...f5 (the Dutch Defense) and 1...g6, the Symmetrical Variation, in which Black mirrors the fianchetto.

Eccentric replies also have names. 1...h5 is the Lasker Simul Special, and 1...h5 2. Nf3 h4 is the Van Kuijk Gambit. Analysis suggests 1...h5 concedes only a slight edge, and in Lichess games Black has actually scored better after it than after the main replies. By contrast, 1...g5, the Myers Defense, scores poorly for Black.

The engine judges the position after 1. g3 roughly balanced and prefers 1...c5, 1...e5 and 1...e6. Results in online play are close to even, with a small plus for White. The opening is one of the more frequently played first moves. The play it produces is usually maneuvering rather than forcing, and the theory a player needs depends mostly on which opening the game transposes into.