He also had success against other world-class grandmasters such as David Bronstein, Lev Polugaevsky, and Efim Geller. He achieved a plus score in the 20 games he contested against World Champions. But in addition to his aforementioned dismal score against Averbakh, he could only score +0−3=2 each against excellent defenders Tigran Petrosian[2] and Viktor Korchnoi.[3]