It is more the size difference that makes teh difference...height.
e.g An average 7foot russin giant will always always stand a chance against a 6'2 talanted boxer,
If you cant get close enough you cant do damage.
Also those 7footers prob have 90" reaches
I agree that height makes a huge difference too;
I believe I mentioned that in my post.
The increased musculature however, is just as important.
Also, the extremely tall guys fighting, have correspondingly high power, due to their body mass.
If Mike Tyson had the physique of Bob Fitzsimmons,
he wouldn't have been a force in modern heavyweight boxing.
The overall trend is toward top heavyweights getting stronger
and taller.
Boxers today, would make the classic boxers look like midgets.
The dramatic size increase is not always matched with a dramatic skill increase,
because the bigger you are, the less skill you need to win.
"Strength and size is in modern combat important...but it will always play second to Mental Conditioning...if your Mentally weak all the strength and size WHEN the PRESSURE is FORCED onto you... will not save your massive size and strength of a body."
That's true unless the size advantage is absolutely ridiculous, like it is with Valuev.
He was carried to a championship, relying purely on his size. He beat guys with greater heart than him,
because they simply didn't have the tools to beat his size advantage.