Here's something I heard a few years ago...
... The widely held belief that Rocky Marciano was the only heavyweight champ to retire undefeated is not true because he turned professional in 1946 under the name of Rocky Mack and was beaten in his first fight. He then returned to fight as an amateur and then turned pro in 1947 as Rocky Marciano. It is only under his second name that he remained undefeated. This may or may not be true... it could easily be an urban myth, but I would be interested to find out if anybody else has heard this story??
Bookmarks