The basic reason why Mr. Ungar switched from gin rummy to poker was that Stu was a tiny bit too good at it. So skilled was he, that no one possibly could equal him. Even the apparently experts who were meant to be the best at gin were beat when they played with Stu. One of these gin rummy professionals was Harry Stein, called, "Yonkie". Harry suffered such a belittling beating at the hands of stu that he allegedly stopped playing it as a pro and never showed up at a gin tournament.
Accordingly, with a image like that it wasn’t very long before everyone became weary of wagering against stu. He could find no games and in his bleakness he started doing something no one had performed prior. Stu offered starting handicaps to potential adversaries in the wish that they may compete against him if they believed they held an edge. He deliberately played from a negative position and one tale has it that he even competed with a constant cheater. During the contest, he received a few words of wisdom that the absconder was at it yet again but stu assured that he was aware of the dishonestly and he would still come away with a win, which he did, of course.
The same trend followed Stu Ungar to Las Vegas. He won so often that the casinos began asking him not to gamble in their poker rooms anymore. The reason for it was that other casino players refused to be seated at the table if Stu was playing.
Stu Ungar is remembered better for his abilities in hold’em poker but he himself always insisted that he was a whole lot more skilled at gin rummy.
He beat Doyle Brunson in the WSOP in 1980 to become the youngest world champion. Because of his features that made him seem far younger than he was, he was nicknamed, "The Kid".