Nimzo-Indian Defense

The Nimzo-Indian Defense is a queen pawns opening named after a great player called Aron Nimzowitsch. It uses pieces to gain influence over the center (knight and bishop) rather than the pawns. The line is: 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4. White gains control and threatens to play 4. e5. However, 3. ...Bb4 pins the knight against the queen and 5. e4 is met with 5. ...Bxc3+, 6. bxc3, and then 6. ...Nxe4, and black wins the e pawn. It can also transpose into the Ragozin Defense of the Queens Gambit Declined. Here it is: