Willie Mosconi(1913-1993)

When he appeared in September 1962 on "What's My Line?" he had to sign in as "Mr X", due to the fame of his name. He was credited, to the audience, as being the "World's Pocket Billiard Champion". Once his identity was revealed to the panel, he explained that, while working on the film "The Hustler", he had to train Paul Newman, but Jackie Gleason seemed to already know his way around the table.