In the 60's, 70's, and 80's the Soviets seemed to have every advantage in athletic training compared to the Europeans. They had an excellent system for selecting athletes at an early age based on their natural genetic abilities, they had the best physiologists to develop training methods, and they had full support for their athletes to allow them to devote all their time to training and racing. How were the Europeans able to stay ahead of the Soviet block bicycle racers?
Professionals only really came from the Eastern bloc in the late 80s-early 90s.
Guys like Soukhourochenkov, Ampler and Ludwig on the road, Hesslich and Hubner on the track were the equal to any riders in the west.
Hard to beat Bernard Hinault at the Tour de France when the biggest tour you ride is the Peace Race.