Jarrel miller when juiced up was probably strong as hell. Nikolay Valuev for all his other limitations had to be very strong Ed “ too tall “ Jones was useless in the ring but incredibly strong.
At 7 feet and 330 pounds, and breaking a testing device with his grip strength, Nikolai Valuev had to the strongest, or close to it, for well known boxers.
Ali doesn't get enough credit for his strength--some of those body shots Foreman laid on him in the Rumble would have felled a tree!! (Joe Frazier landed some PULVERIZING body shots against Ali in the FOTC and the Thrilla--you HAVE to have some serious strength to absorb those kinds of punches!!)
Going away from the size matters mob, Ali is surely the greatest specimen in heavyweight history. 210-212 pounds at his peak, fastest feet/hands blend ever, good power when he wanted it, incredible durability both to the head and body and great reserves of stamina. Reflexes abound at his finest as well. In addition to that you had the unwavering confidence, will to win and mental strength. Little wonder he performed the feats he did. It's unfair really.
Up until recently I thought it was Mike but come to the conclusion it's Ali. 6'3, GOAT level chin durability, body durability, hand speed, foot speed, reflex speed with ATG strength and ATG stamina. He has ONE non ATG physical attribute; his punching power, and even then he's still like a 7/10 in this aspect. It's crazy.
Until some other heavyweight comes along who we know can lift a cow over his shoulders or tug a pickup truck around his backyard via rope, I’ll have to stick with Big George.
Mike who? The guy who got shoved around the ring by Evander and manhandled by Buster Douglas? THAT Mike?
Being a GOAT level athlete doesn't necessitate strength, as long as you make up for it elsewhere. Mike is slightly heavier than Ali despite being 5 inches shorter, actually has faster hands imo and hits so much harder it's not even funny. BUT, yes, inferior reflexes, vastly inferior stamina and (somehow) vastly inferior strength outweighs his slightly faster hands and bigger powah. Not to mention ring IQ and mental toughness. Not physical attributes but Ali obliterates him there regardless.