The main reason for why Stu changed from gin to poker was that he was a bit too skilled at it. So skilled in fact, that no one possibly could stand up to him. Even the so-called champions who were meant to be the best at gin were demolished when they competed against Mr. Ungar. One of these gin rummy player was Harry Stein, called, "Yonkie". Harry suffered such a humiliating beating at the hands of stu that he evidently quit participating in it professionally and never resurfaced at a gin rummy tournament.
Of course, with a reputation like that it wasn’t long before everyone became weary of betting against mr. ungar. He couldn’t find any games and in his agony he began doing something no one had attempted prior. Stu offered beginning handicaps to potential competitors in the wish that they might compete against him if they believed they had an edge. He deliberately played from a negative arrangement and one account has it that stu even competed against a consistent cheater. Mid match, he received warnings that the bad egg was at it once again but Stu Ungar guaranteed that he was aware of the cheating and he would still acquire a win, which of course, he did.
The same trend followed Stu Ungar into vegas. He won so much that the casinos started requesting that he not to gamble on their rooms anymore. The basis for it was that other casino customers would not be seated at the poker table if he were playing.
Stu Ungar is recollected better for his abilities in texas holdem poker but he himself always said that he was far better at gin rummy.
He beat Doyle Brunson in the World Series of Poker in 1980 to become the youngest world camp. Because of his looks that made him seem far younger than he really was, he was nicknamed, "The Kid".