Indian Defense

A45

About this opening

Black has not blocked the center, so d5 is still coming and so is a fianchetto. c4 is the most played move here. It grabs more space, though look at the score before assuming space wins: the Indian setups are built to attack a big center rather than to prevent one. Nf3 is flexible and takes e5 away first. Bg5 pins the knight and fights for the d5 square before Black picks a system. e3 is safe but passive, and it scores worst of the popular moves because it hands Black the initiative. The choice here is between taking space and keeping things simple.

Plans

Play c4 to take space and dare Black to hit the center.
Play Nf3 first to take e5 away and stay flexible.
Pin the knight with Bg5 to fight for d5.
Build the full center with e4 only if you can hold it.

Where the pieces belong

Pawn: c4, claiming space on the queenside
Knight: c3, supporting d5 and e4
Bishop: g5, pinning the knight that guards d5
Pawn: e4, the full center if you can hold it
Knight: f3, covering e5

You take space and Black attacks it. The King's Indian and Nimzo setups are both designed to make your center a target, so hold it only if every square in it is defended.