The basic reason for why Stu changed from gin rummy to poker was that he was a bit too skilled at it. So good was he, that no one was able stand up to him. Even the so-called experts who were supposed to be the best at gin rummy were defeated when they played against Stu Ungar. One of these gin rummy masters was Harry Stein, called, "Yonkie". Harry suffered such a crushing blow at the hands of mr. ungar that he evidently quit competing in it professionally and never showed up at a gin rummy tournament.
Of course, with a notoriety like that it was not long before gamblers became afraid of gambling against stu. He couldn’t find any games and in his boredom he started doing something no one had done prior. He issued starting handicaps to potential opposing players in the high hopes that they might compete with him if they believed they held an edge. He deliberately started from a negative arrangement and one account has it that stu even played against a consistent absconder. Mid contest, he get warnings that the cheater was at it yet again but stu stated that he deduced of the dishonestly and he would still come away with a win, which he did, of course.
The same problem followed Stu Ungar to sin city. He won so frequently that the casinos began asking him not to gamble on their poker rooms anymore. The explanation why was that other poker room players refused to sit at the poker table if he were seated.
Stu Ungar is recollected better for his achievements in holdem poker but he himself always said that he was considerably more accomplished at gin rummy.
He defeated Doyle Brunson in the WSOP in Nineteen Eighty to become the youngest world camp. Because of his features that made him appear far younger than he was, he was nicknamed, "The Kid".