head-to-head

Ali
Liston
Tyson

p4p

Ali
Louis
Johnson

Rocky Marciano would be in for a short and painful night. Tyson will beat him from pillar to post and stop him in a hurry.

I can make a 5 minute compilation that makes Muhammad Ali look like a powerpuncher. Doesn't mean that's what he was.

My top5 p4p is

Muhammad Ali
Sugar Ray Robinson
Henry Arstrong
Joe Gans
Willie Pep