The main basis for why Stu Ungar changed from gin rummy to poker was that he was a bit too good at it. So skilled was he, that no one possibly could stand up to him. Even the so-called professionals who were supposed to be the best at gin rummy were beat when they played with Stu Ungar. One such gin player was Harry Stein, nicknamed, "Yonkie". Harry was handed such a humiliating beating at the hands of stu that he apparently stopped competing in it professionally and never resurfaced at a gin rummy tournament.
Accordingly, with a notoriety like that it wasn’t very long before people became weary of gambling against mr. ungar. He couldn’t find any games and in his agony he started doing something no one had performed prior. He presented beginning handicaps to potential competitors with the hope that they might play opposed to him if they believed they had an edge. He deliberately began from a disadvantageous position and one story has it that he even played against a constant bad egg. Mid game, he received warnings that the bad egg was at it once again but stu assured that he deduced of the fraudulent activity and he would still actually win, which he did, of course.
The same trend followed Stu Ungar into sin city. He won so often that the casinos began requesting that he not to wager in their poker rooms anymore. The reason for it was that other casino visitors refused to sit at the table if he were playing.
Stu Ungar is recalled more for his achievements in hold’em poker but he himself always said that he was considerably better at gin rummy.
He defeated Doyle Brunson in the WSOP in Nineteen Eighty and became the youngest world camp. Because of his looks that made him seem far younger than he was, he was nicknamed, "The Kid".