Why wasn't Campbell able to hurt Bizier...

Well, what you don't want us to tell you is probably the main factor

 

Cuz he is an old washed up has been that took the fight on short notice against a stronger opponent? And yeah, size DOES matter.

 

Depending on his ideal weight size does matter. Some guys fight draining themselves. When they finally stop they appear to have power they didn't have before going up a weight class. I think Ortiz would be an example of a guy that fought better one weight class above.

John Duddy got his first 'official' loss when Pat Burns tried to take him down in weight and Billy Lyle took his OH. He drained and bloated up.

If Nate is comfortable at 140 going up he simply will not carry power. Jack Loew when asked about Kelly going to SMW some years ago said something like, "The chins up there will be harder to crack." Look at the two fighters he DIDN'T stop when he moved up. The premise that size doesn't matter here I think is just flat out wrong.

 

Bizier has a pretty decent chin, too.

 

Also, Pavlik said he landed a flush shot on Hopkins and NOTHING. This may have been a natural 2 weight class difference but it illustrates the point. No one at 160 ever took a flush shot from Pavlik like and showed no effects from it.

 

I'm not hinting at an hidden agenda.

It's because you wrote "Please don't say the weight difference". My point was that the difference in size and strenght is the main thing to consider. You had a guy who certainly looked like he could make 135 against a physical WW who might be on his way to 154.

 

nate been washed for years

 

Because not everybody has the same power or chin?
Power and chin are relative, you seem to be preoccupied with this idea that you have it or you don't.

 

x 2

 

He is 40 years old. Thats a start.

 

Bizier has a solid chin, he took some flush shots. I think Campbell's bodyshots did work a good bit and slowed down Bizier to a degree.
But....
SIZE DOES MATTER too. AGE does matter too. Campbell was in a bigger weightclass and at an old ass age. And you're mystified why Campbel couldnt drop Bizier?!?!

 

You could use this same question with any old fighter! Makes no sense.