The Nimzowitsch-Larsen Attack, also known as Larsen's Opening or the Queen's Fianchetto Opening, is a chess opening defined by the move 1.b3. ECO code: A01. It is colloquially nicknamed the "Baby Orangutan" in reference to the Polish Opening (1.b4), known as the "Orangutan."

History

The opening is named after Aron Nimzowitsch (1886–1935), the Latvian-Danish grandmaster and leading proponent of hypermodernism, and Bent Larsen (1935–2010), the Danish grandmaster who played 1.b3 frequently in the late 1960s and early 1970s. English amateur John Owen employed the approach as early as the 1870s, essentially playing the Owen's Defence (1.e4 b6) with an extra tempo. Bobby Fischer played 1.b3 on five occasions in 1970. Soviet GM Vladimir Bagirov was a dedicated practitioner, playing it approximately 100 times between 1976 and 2000, scoring roughly 54% wins and 38% draws. The opening suffered a notable setback when Larsen lost to World Champion Boris Spassky in just 17 moves at the 1970 USSR vs. Rest of the World match in Belgrade.

Main Lines & Variations

White prepares to fianchetto the queen's bishop to b2, where it exerts pressure on the a1–h8 diagonal and helps control the central squares d4 and e5 in hypermodern fashion.

Against 1...e5, White can:

• Allow the classical e5/d5 pawn centre and undermine it hypermodernly: 2.Bb2 Nc6 3.e3 d5 4.Bb5

• Contest d5 in Sicilian style: 2.Bb2 Nc6 3.c4

Against 1...d5, White can:

• Prevent ...e5 with a reversed Nimzo-Indian Defence structure: 2.Bb2 c5 3.e3 Nc6 4.Nf3 Nf6 5.Bb5

• Allow ...e5 and transpose to earlier lines

Other independent responses include 1...c5, 1...Nf6, 1...f5, 1...b5 (Polish), 1...b6 (Symmetrical).

Nimzowitsch himself preferred the move order 1.Nf3 d5 2.b3 rather than the direct 1.b3, but the direct approach offers "more variety and more scope for tricks and traps on the a1–h8 diagonal."

Key Positions

After 1.b3 – White prepares Bb2 with pressure on the long diagonal.

Strategic Themes & Plans

White controls the centre from a distance, relying on the fianchettoed bishop rather than pawns. The opening often leads to rich middlegame positions with chances for both sides. Modern super-GMs including Hikaru Nakamura, Magnus Carlsen, Richárd Rapport, Ian Nepomniachtchi, and Baadur Jobava have employed it as a surprise weapon, particularly in rapid and blitz events. Czech GM Pavel Blatny and Armenian GM Artashes Minasian are noted specialists of the system.