The only fighter that came close to Ali was Joe Bugner. The rest were all second rate versions of Ali.
Klitschko would have been dragged through the early rounds, plodding his way after the master, then later in the fight, he'd have been put to sleep.
Sugar Ray Robinson is the greatest boxer who ever lived. Boxing record Total fights 200 Wins 173 Wins by KO 108 Losses 19 Draws 6 No contest 2
As I grew up, the only name that came up as the greatest was the Brown Bomber, Joe Lewis. 70 fights, 66 wins, 52 by KO. It was only when Ali burst onto the scene, did thinking change.
Mike Tyson was totally overrated. Not a boxer, just a thug. Bruno had him on the ropes and would have murdered him if he wasn't planning the next stage of his career in pantomime. Lucky escape for the Ear Biter.