Nimzo-Indian Defense
A popular line of the
Indian defense after the
queen pawn opening, named after
Aron Nimzowitsch.
Black's main goal in this
opening
is the prevention of
White's advance of the King pawn,
e4.
The opening moves which define the Nimzo-Indian defense are
1. d4 Nf6
2. c4 e6
3. Nc3 Bb4
(If necessary, see
chess notation for help decoding the moves.)
Black's dark-square bishop is often exchanged for White's
queen knight at c3, giving White a doubled pawn
on the c-file at the expense of maintaining Black's
bishop pair. White may choose to preserve his/her pawn structure
with 4. Qc2 (classical variation) which has the disadvantage
of removing one of the queen pawn's defenders. Usually White accepts
the doubled pawn and will make use of the half-open b-file
with his/her queen rook.
The Encyclopedia of Chess Openings denotes
this opening by the code ECO E20,
with main variations also in the ECO chess codes E3 series.