Irina Rodnina won 10 World titles and 3 Olympic championships, a feat made even more impressive by the fact that she was a pairs skater and won both World and Olympic titles with both of her partners, Alexei Ulanov and Alexandr Zaitsev.
As much as the Protopopovs did before her, Rodnina represented a new era in pairs skating-one that emphasized speed, athleticism and power. Even today, Rodnina is recognized as a singular force in the sport. Which brings me to the entire point of this thread... Her partners.
Rodnina won 4 world titles and 1 OGM with Ulanov (and of course there was the whole business of R&U breaking up because Ulanov fell in love with another pairs skater). With Zaitsev, hand picked to skate with Rodnina after R&U imploded, she won 6 world titles and 2 OGM.
Were Ulanov and Zaitsev, in terms of their skating, simply interchangeable? Or, were there distinctions in their skating, besides the fact that they were, you know, two different people. Or, was Rodnina such a dominant force, she could have partnered with virtually anyone and win titles?
ETA: How did R&U compare to R&Z? From what I've seen on youtube, I prefer R&Z, but I don't have any definitive reason as to why, its more a personal preference.