Queen''s Indian Defence1. d4 Nf6 2.c4 e6 3.Nf3 b6
In the Queen''s Indian Defence Black prepares to fianchetto his light-squared bishop to b7, in order to take under his control the central e4-square. The Queen''s Indian Defence is the little brother of the Nimzo-Indian. In both openings Black takes indirect control over central squares.
Main Variation with 4.g3: 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.g3
This is by far the main variation. White also prepares the fianchetto of his light-squared bishop followed by short castling. Black now develops his light-squared bishop immediately to b7, before worrying about the development of his kingside, or he puts the bishop on a6 and attacks the c4-pawn.
Petrosian System with 4.a3: 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.a3
This variation bears the name of the 9th chess world champion Tigran Petrosian. With the modest looking pawn move White prepares Nb1-c3, without Black being able to pin the knight with ...Bf8-b4. Ideally White would like to follow up with e2-e4 occupying the centre thanks to the support of the knight on c3 and possibly later the queen, which in many variations is placed on the c2-square. Black mainly continues with 4...Bc8-b7 and then 5...d7-d5 and fights for the control of the e4-square. But he can also play 4...Bc8-a6 in order to first entice the queen on to c2 and then move the bishop to b7.
Central System with 4.e3: 1.d4 Nf6 2.c4 e7 3.Nf6 b6 4.e3
In the Central System White adopts a solid setup and develops his pieces according to the pattern bishop on d3. Knight on c3 and the dark-squared bishop on b2. But this development does not pose any problems for Black and he has no problems posting his pieces on active squares and fighting for the centre with ...d7-d5.