Nimzo-Indian Defense: St. Petersburg Variation

1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 b6

Nimzo-Indian Defense: St. Petersburg Variation is catalogued under ECO code E43. It is reached after 4 moves (8 half-moves): 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 b6. After the last move it is White to play. White opens 1. d4. It is a named variation of the Nimzo-Indian Defense, which has 99 catalogued lines in total. 3 deeper lines continue from here, listed below.

Position shown after the last move; White to play.