Nimzo-Larsen: 1. b3 (A01)|
(Wikipedia, 2012): Larsen's Opening (also called the Nimzo–Larsen Attack, Queen's Fianchetto Opening, Owen's Opening or the Greek Attack) is a chess opening starting with the move: 1. b3.
It is named after the Danish Grandmaster Bent Larsen. Larsen was inspired by the example of the great Latvian-Danish player and theoretician Aron Nimzowitsch (1886–1935), who often played 1.Nf3 followed by 2.b3, which is sometimes called the Nimzowitsch–Larsen Attack. It is classified under the A01 code in the Encyclopaedia of Chess Openings.
The flank opening move 1.b3 prepares to fianchetto the queen's bishop where it will help to control the central squares in hypermodern fashion and put useful pressure on Black's kingside. Often, the b2-bishop is a source of recurring irritation for Black, and it should not be treated lightly.
Although Bent Larsen was initially very successful with this opening, it suffered a setback in the 1970 USSR vs. Rest of the World match in Belgrade, in which Larsen played this opening against reigning World Champion Boris Spassky and lost in 17 moves. Of the 42 games between Spassky and Larsen, Spassky won overall with 19 wins, 6 losses, and 17 draws.
Larsen was also decisively defeated when playing this opening against Rosendo Balinas, Jr. at Manila in 1975.
Notably however, the opening received interest from Bobby Fischer the same year, who employed 1.b3 on at least five occasions, winning all five, including games with GMs Filip and Mecking (Palma de Mallorca 1970 Interzonal), GM Tukmakov (Buenos Aires 1970), and GM Andersson (Siegen 1970).
The move 1.b3 is less popular than 1.g3 (Benko's Opening), which prepares a quick kingside castling. According to ChessBase, 1.b3 ranks sixth in popularity out of the possible twenty first moves while the fifth-ranking 1.g3 is about three times as popular. Larsen frequently used unconventional openings of this sort. He believed it to be an advantage in that Black, usually unfamiliar with such openings, is forced to rely on his own abilities instead of relying on memorized, well-analyzed moves of more common White openings.
The relative unpopularity of 1.b3, compared to 1.g3, is probably because 1.g3 usually leads to fianchettoing the king's bishop with 2.Bg2. Later, c4 is often used to strengthen the fianchettoed bishop's diagonal. However, after 1.b3 and 2.Bb2, if f4 is played to strengthen the bishop's diagonal, this weakens the kingside.
In more recent times, 1.b3 has been repopularized in freestyle chess, for similar reasons – a player with unlimited access to computer-based opening books can build up a large opening repertoire and thus create a theoretical minefield for Black, unless he or she is either prepared well enough to go into a safe line, or manages to lead the game into an even more offbeat line, negating the book difference.
Black has several options to meet 1.b3. The most common are:
1...e5, the Modern Variation, is the most common response, making a grab for the centre and limiting the scope of the White bishop. Play on this line typically continues 2.Bb2 Nc6, attacking and defending the e5-pawn, respectively, and then 3.e3 d5 4.Bb5 Bd6 5.f4 is the main line.
1...d5, the Classical Variation, is the second most common, also making a grab for the centre and preserving the option to fianchetto the king's bishop to oppose the White one. Here, White uses 2.Nf3 to hopefully transpose to a reversed Nimzo-Indian Defence or another Indian defence. This can also be reached by the move order 1.Nf3 d5 2.b3.
1...Nf6, the Indian Variation, developing a piece and not committing to a particular pawn formation just yet. 2.Bb2 and if 2...g6 then 3.e4, taking advantage of the pinned knight (e.g., not 3...Nxe4 4.Bxh8, winning a rook at the price of a pawn).
1...c5, the English Variation, retaining the options of ...d5, or ...d6 followed by ...e5. 2.c4 transposing to an English Opening or 2.e4 tranposing to a Sicilian Defence.
1...f5, the Dutch Variation. 2. Nf3.
Less common lines include:
1...e6, with Black setting up a variation on the French Defence. Here Keene recommends 2.e4 and if 2...d5 then 3.Bb2.
1...c6, a Caro-Kann variant preparing for ...d5. Again Keene recommends 2.e4 and if 2...d5, 3.Bb2.
1...b6, the Symmetrical variation, is completely fine for Black.
1...b5, the Polish Variation.
'Encyclopaedia of Chess Openings' (ECO, 1979).
Nimzo-Larsen: 1. b3 (A01) ~ "Main line":
Nimzo-Larsen Attack's main line: 1. b3 e5 2. Bb2 Nc6 3. e3 d5 4. Bb5 Bd6 5. f4 (photo above) --- f6