The primary reason for why Stu changed from gin rummy to poker was that he was a little too good at it. So good was he, that no player was able equal him. Even the so-called champions who were supposed to be the most favorable at gin rummy were beat when they played against Mr. Ungar. One such gin rummy professionals was Harry Stein, called, "Yonkie". Harry Stein was handed such a belittling defeat at the hands of mr. ungar that he allegedly quit playing it as a pro and never showed up at a gin rummy tournament.
Accordingly, with a honor like that it was not too long before everyone became shy of wagering against mr. ungar. He couldn’t find any matches and in his agony he began doing something no one had performed prior. He offered starting handicaps to potential adversaries with the hope that they might play against him if they believed they held an advantage. He deliberately played from a negative position and one account has it that stu even competed against a consistent bad egg. Mid match, he get warnings that the bad egg was at it again but Stu Ungar stated that he deduced of the cheating and he would still win, which he did, of course.
The same problem followed Stu Ungar into Las Vegas. He won so much that the casinos started requesting that he not to gamble in their rooms anymore. The reason for it was that other poker room players refused to be seated at the poker table if he were playing.
Stu Ungar is remembered more for his accomplishments in holdem poker but he always insisted that he was a whole lot more accomplished at gin rummy.
He defeated Doyle Brunson in the WSOP in Nineteen Eighty and became the youngest world camp. Due to his features that made him seem far younger than he actually was, he got the nickname, "The Kid".