david tua imo if we mean literally then it has to be tua due to humans getting bigger and stronger but in context of the time big george and marciano
Roberto Duran for how he practically raped Davey Moore with his fists Mike Tyson for a whole assortment of knockouts Jack Dempsey for what he did to Jess Willard Marciano for what he did to Roland LaStarza in busting his arms so he could no longer defend himself, his savage beating of Ezzard Charles in the final round of their first fight, and his savage finish of Archie Moore Ray Mercer for how he nearly killed Tommy Morrison and even though it wasn't boxing rules continued to pound on an unconscious Tim Silvia Joe Louis brutalized countless opponents on ***** street because of his handspeed and brutal finishing ability. They couldn't fall fast enough to avoid some of the blows :bbb
Dempsey, Greb, Fullmer (Fullmer Vs. Peret is the most awful beatings I have ever seen) , Liston, Duran, Tyson.
I thought about mentioning Fullmer-Paret! That indeed was a terrible beating and is believed to have helped contribute to his death against Emile Griffith(R.I.P. Benny "Kid" Paret) Fullmer also brutalized Carmen Basilio twice too Harry Greb was brutal with his hands and whatever else he could use on you. The fact that Gene Tunney went the distance with him while sustaining such a beating was just inhuman. Maybe they were tougher back then.....and not nearly as quick about stopping fights as they are today(thank goodness they are nowadays)