22 f3-f4! prepares doubling on e-file with tempo 23 Re1-e4 1-0 Ivanchuk vs Anand, 2007  (E37) Nimzo-Indian, Classical, 23 moves, 1-0 28/29 - Re8xe3! leads to doubling on 7th with Ra8-a2+, -Qf5-f2 Anand vs Carlsen, 2009  (D35) Queen's Gambit Declined, 46 moves, 0-1 2 games