[%c_effect e4;square;e4;type;GreatFind;persistent;true] White's typical plan in this pawn structure. The diagonal opens for the bishop and there's the possibility of playing e4-e5 and trying to attack on the kingside.
1. d2d4  1... g8f6  2. c2c4  2... e7e6  3. b1c3  3... f8b4  4. e2e3 Robson has been faithful to the most classical of the Nimzo-Indian variations throughout the tournament, showing that it's possible to gain attacking positions with the queen's pawn as well. 4... e8g8  5. f1d3  5... d7d5  6. a2a3  6... d5c4 So decides to keep his bishop. 7. d3c4  7... b4e7  8. g1f3  8... c7c5  9. e1g1  9... a7a6  10. d4c5  10... e7c5  11. d1e2  11... b7b5  12. c4a2  12... c8b7 