Frazier is at the top for me due to his consistent body attack but I find it tough to rate the others. I guess I would have it something like this: Frazier, Dempsey, Marciano, Tyson, Patterson, Tua Dempsey landed some powerful, crumbling body punches every now and then but wasn't very consistent with his attack. I have seen him double over some opponents with left hooks to the body. Marciano deserves extra credit for throwing punches to whatever body part he could find, including the arms and shoulders. Tyson could be higher actually. He abandoned the use of body attack by 1989. Patterson ended most of his combinations with left and right hooks to the body but he didn't really break his opposition down this way. I can't remember Tua doing much work to the body at all, perhaps I'm ignoring some of his best performances.
Tyson - most power to the body and best technique Frazier - consistant and big painful bodyshots Marciano - excellent bodypuncher, heavy, painful Dempsey - could be consistent and land some good blows but not quite as good as the others Tua - not a consistent bodypuncher but I dont want to take his left hook to the body Patterson - not the same forced as the others
Frazier- Relentless body attack. Marciano- Almost as good as Frazier but liked to headhunt more. Dempsey- Look at what he did with Willard Tyson- He was good but became a headhunter throughout most of his career. Patterson- Lighting fast hands with a good balanced attack Tua- I haven't seen too much Tua bodypunching.
I strongly suspect that this was a casualty of the 12 round era. Tyson also seemed to abandon his body attack as it became apparent the 15 round era was coming to an end. I don't expect that we'll ever again see bodypunching as a principle tactic unless the longer distance is restored.
Frazier's above the rest. The rest you can argue for each place for each at their best time times or prime or this or that. I think most generally I'd agree with OCD.