Quote Originally Posted by atomic bull
I don't know how you decide who's an all-time great, but you leaving off Dempsey and Marciano makes no sense, Dempsey K.O. d Carpentier and Marciano beat Charles in 2 epic battles, and had Dempsey been active prior to the Tunney bout, Dempsey would had beaten him soundly, Dempsey was perhaps the most fericous fighter to ever step into the ring, Tyson idolized him and even wore his hair like Dempsey early in his career. So your way off.
How I decide an all-time Great:

Quality of opposition
Length of World Class career
Redemption

Then is intangibles like

Originality and poineering qualites
Iconic status
Impact on boxing history (all of them can be connected)

Then to break ties; I bias

Ring Generalship
Technical ability
Impact on society; then if still level
The most crowd pleasing style

And if making an all time Great was as simple as who beat who, then Leon Spinks beat Ali, and Spinks was beaten by Jose Ribalta, who was beaten by Tim whitherspoon, was beaten by Brian Nix, who was beaten by Audley Harrison; so ....

The truth is Carpentier and Charles were more impressive meeting the criteria; such as redemption and quality of opposition, than either Dempsey or Marciano, IMO.