Fianchetto Variation, Carlsbad Variation

The Carlsbad Variation reaches the Fianchetto Variation by way of an early 3. g3, with both knights developed before White castles. Black's 6...Nc6 puts pressure on d4 and keeps both ...e5 and the Panno plan of ...a6, ...Rb8 and ...b5 available, rather than committing to the Classical 6...Nbd7. The knight on c6 is, however, exposed to a d4-d5 advance.

By far the most common reply is 7. O-O. It transposes to the main Fianchetto position with Black to move, where 7...a6 enters the Panno Variation and 7...e5 the Uhlmann-Szabo System. The immediate 7. d5 forces the knight to move before Black has prepared ...a6, and White has scored well with it. The rarer 7. e4 builds a broad center at the cost of blocking the g2-bishop's diagonal, and Black has done better than White in the games reaching it. Engines give White a slight edge in the starting position and favor castling, 7. d5 or 7. h3.