Miguel cotto and ODLH are natural lefthanders but fought orthodox which is preety amazing because you would never have guessed it if they were not open about it. Floyd and Zab are either natural lefthanders or ambidextrous.
Foreman is a lefty. Mostly they get switched just because your typical small time trainer doesn't know how to train southpaws. Edit: actually not sure about foreman. I remember reading some place he was left handed. But now I can't find any confirmation of that. So I am not sure now.
Michael Moorer was right handed but fought southpaw. Vaguely recall hearing Frazier was converted, Cooney too (Not a champion)
I remember it being mentioned by the commentators for one of his early televised bouts that he was a converted southpaw. Photographs show him signing his autograph with his right hand, however. This would probably be a good one to ask Mike himself. (He's supposed to be friendly and approachable to fans, in contrast to many media favored stars.) Johnstown's correct in saying this has happened often because trainers haven't known how to develop a southpaw, much as old time teachers and schools forcibly converted left handed students to unnaturally use the right hand in learning penmanship. Many college coaches apparently didn't have the same issues accommodating the southpaw orientation. Haislet advocated that left handed pupils learn to box as southpaws first, then switch to the orthodox stance so that eventually both positions could be used. (However, it must be acknowledged that getting collegiate fights was never a problem, when dealing with athletes competing on boxing scholarships. Punch for pay is a different matter.) Chuck Davey was schooled as a southpaw at a time when most instructors who provided support for that style were still in the collegiate ranks. Corbett, Jeffries, Basilio, and DLH (not an especially well known fact about Oscar) were all converted southpaws. On the opposite side of the ledger, I can't say for sure what champions were naturally right handed yet boxed southpaw, prior to Jim Watt.
