GM Master Class
Portisch,L used a quick double fianchetto with Nh3-f4 against Geller’s Benko gambit in the Biel 1976 Interzonal and won a tough game.

Portisch,Lajos (2625) – Geller,Efim P (2620)
Benko g3 Fast b3[A58]
Biel Interzonal Biel (3), 13.07.1976

Position 1
Black had earlier sacrificed the exchange for counterplay and now white is playing to convert the material advantage. What do you suggest for white?

White to Play