Lewis/Klitschkos dominate because of their size?

Its hard to say, will Tyson as good as he was in 80's if he's 6'4? or if Holyfield is 6'5?

Its your ability that actually matter. Size does matter when you're getting older which is why Lewis and Klitch last longer on the top compare to smaller size heavyweight.

There are quite many heavyweight that around same size with Lewis but not many as big as Klitchko.

 

Bingo!

 

Size helps if you have a bigger guy of equal skills ans attributes against a smaller guy. But if it was the only factor we would have Valuev-like hw champions all the time. There are plenty of people Lewis and Klitchko size who dont dominate so to say size us the only/main factor is ignorant, just as it is to say it isnt a factor at all