Resignation Trap: Petrosian's 9...Qc7 was rather rare, but 9...dxc4 10.Bxc4 Qc7 was tried many times at Zurich 1953.
Geller criticized his 10.Qc2, suggesting an immediate 10.a4 and 11.Ba3 instead.
11.cxd5?! allows Black to cramp his opponent with 11...c4! Geller should have tried 11.Ne5.
13...Bg4?! is the first of Petrosian's second-rate moves, and Geller recommended 13...Re8, to be followed by ...g6 and ...Bf5 as a better idea for Black.
16...Nc6?! is inferior to 16...b6 17.a4 Rae8 18.Ba3 Rf6 19.Rfe1 Qf7 20.Nf1 Rfe6 according to Max Euwe.
After 26.e5 White's space advantage is apparent; what was once a weak e-pawn is now a thorn in Black's side.
Geller's 27.Nf1! (threstening 28.Ne3) and 29.Qc1! seriously endanger the Armenian's queen.
With 29...Nxd4, Black gets three pawns for his piece, but the piece prevails.
With 39.Ne3? Geller overlooked a simpler win with 39.Ne7+ and 40.Nxf5, but he had only a few seconds left on his clock to make it to move 40.
The game was adjourned after Black's 40th move and some spectators were surprised to see the game resumed, for Black is lost. His 44...Rc4?? was the final nail in his coffin.