Chess Opening Theory/1. b3

1. b3 · Larsen Attack
Also known as Nimzowitsch-Larsen Attack or just Queen's Fianchetto Opening, it is named after Aron Nimzowitsch and Bent Larsen.

1.b3 prepares to fianchetto the queen's bishop to b2, where it will fight for the central squares and point towards Black's kingside.

This is an example of a hypermodern opening, as it prepares to control the center with a bishop rather than a pawn (the classical style). Black can accept the invitation to cover the center with pawns (following classical principles) or fianchetto their own bishop.

Black's responses

 * 1... e5 (Modern Variation) - This move is the most common, as it not only grabs the center but also limits the scope of the white bishop after 2. Bb2 Nc6.


 * 1... d5 (Classical Variation) - Another common response, as it also grabs the center. This also preserves the option to fianchetto the black bishop to g7 to oppose the white one. White can play 2. Bb2 or 2. Nf3.


 * 1...Nf6 (Indian Variation) - Prepares to fianchetto the bishop to g7 immediately to oppose the white bishop on b2. However, if Black does play g6 after 2. Bb2, White can play 3. e4!, threatening to kick the knight on f6. 3... Nxe4?? loses to 4. Bxh8.


 * 1... c5 (English Variation) - Retains option of 1... d5 while also being a good transpositional tool. 2. e4 transposes into the Sicilian Defense, and 2. c4 transposes into the Symmetrical English. 2. Nf3 is also playable.


 * 1... f5 (Dutch Variation) - This is a rather unexplored alternative. 2. d4 and 2. Nf3 are most commonly played after this, though 2. e3 and even 2. e4!? (borrowing ideas from the Staunton Gambit) are both possible.


 * 1... e6 - Sets up a variation of the French Defense. 2. e4 d5 3. Bb2 is the most common and recommended line.


 * 1... c6 - Sets up a variation of the Caro-Kann Defense. 2. e4 d5 3. Bb2 is the most common and recommended line.


 * 1... Nc6 - Supports the advance of the e-pawn but allows 2. d4, pressuring the knight.


 * 1... b6 (Symmetrical Variation) - Black copies White's idea. This is perfectly fine for Black.


 * 1...b5!? (Polish Variation) - A fun alternative to the other moves. Transpositions are now impossible.


 * 1...a5!? - Somewhat playable, trying to ruin White's fianchetto, but seeing that White will likely castle on the kingside, this is not that useful.

Statistics

 * Estimated next move popularity
 * e5 43%, d5 27%, Nf6 15%, c5 6%, b5 2%.

Theory table
1.b3