....I think it's evident that Muhammad Ali would be 49-0 with 49 KOs (and probably would have never seen the 6th round). Unfortunately for Mr. Marciano, if he fought the same 61 total fights Ali did, he would end up 40-21, unlike Ali going 56-5. Marciano's losses would be:

Sonny Liston I - KOd in 3
Sonny Liston II - KOd in 1
George Chuvalo I - KOd in 4
George Chuvalo II - KOd in 1
Joe Frazier I - KOd in 4
Joe Frazier II - KOd in 3
Joe Frazier III -KOd in 1
Buster Mathis - UD
Ken Norton I - KOd in 3
Ken Norton II - TKOd in 3
Ken Norton III - KOd in 2
George Foreman - Towel thrown in in 1
Ron Lyle - KOd in 3
Joe Bugner - UD
Jimmy Young - TKO in 6
Earnie Shavers - KO in 1
Leon Spinks I - KO in 7
Leon Spinks II - KO in 3
Alfredo Evangelista - UD
Larry Holmes - KO in 5
Trevor Berbick - KO in 5