33 Qg5-f6+! Black e7-pawn protects f6-, interposes e8-empty sqs S Zhigalko vs A Iljushin, 2010  (B31) Sicilian, Rossolimo Variation, 33 moves, 1-0 23 Rc4xc5! Black c6-queen must protect the b7-checking square Le Quang Liem vs Naiditsch, 2010  (D39) Queen's Gambit Declined, Ragozin, Vienna Variation, 35 moves, 1/2-1/2 37 Rb7-e7!! Black f6-queen must interpose the g7-mating square Kamsky vs B Esen, 2010  (A43) Old Benoni, 60 moves, 1-0 29 ... Rd8-d6? leaves c8-sq for removal of guard 30 Bb7-c8! 1-0 O Ulvestad vs I A Horowitz, 1946  (D74) Neo-Grunfeld, 6.cd Nxd5, 7.O-O, 30 moves, 1-0 4 games