With over 80 fights to his name and 68 knockouts, 23 of which were in the first round, Shavers could certainly lay claim to being the hardest punching boxer of all time. Very nice article. This is why heavyweight class exist, because it do make you punch harder. Is the WBC belt the best? Featuring: Tyson Fury, Oleksandr Usyk, Deontay Wilder, Anthony Joshua, Dillian Whyte, Andy Ruiz, Joseph Parker, Martin Bakole, Jared Anderson, Filip Hrgovi, Joe Joyce, Frank Sanchez and more. 10 to No. Rocky Marciano usually weighed around 185-190 and has the highest knockout percentage of any heavyweight.