Queen's Indian Defense: Kasparov-Petrosian Variation, Polovodin Gambit

The Queen's Indian Defense: Kasparov-Petrosian Variation, Polovodin Gambit is a chess opening classified under ECO code E12 in the Indian Defences family, where Black responds to 1.d4 with 1...Nf6, including the Nimzo-Indian, Queen's Indian, and King's Indian. It is reached after 7 moves: 1. d4 Nf6 2. c4 e6 3. Nf3 b6 4. Nc3 Bb7 5. a3 d5 6. cxd5 Nxd5 7. e4. The resulting position leaves black to move.