The basic reason for why Stu changed from gin to poker was that he was a tiny bit too skilled at it. So skilled was he, that no one could stand up to him. Even the commonly called experts who were meant to be the greatest at gin rummy were crushed when they played against Stu Ungar. One of these gin rummy professionals was Harry Stein, nicknamed, "Yonkie". Harry Stein suffered such a belittling defeat at the hands of stu that he apparently stopped competing in it professionally and never resurfaced at a gin rummy tournament.
Certainly, with a honor like that it was not very long before people became weary of competing against stu. He could not find any matches and in his desperation he started doing something no one had attempted before. Stu offered starting handicaps to potential adversaries in the hope that they may compete with him if they believed they had an advantage. He deliberately began from a bad arrangement and one story has it that he even competed against a constant bad egg. Mid contest, he get advice that the cheater was at it once again but stu stated that he knew of the cheating and he would still acquire a win, which he did, of course.
The same trend followed Stu Ungar to Las Vegas. He won so frequently that the casinos started asking him not to play in their casinos anymore. The reasoning behind it was that other casino clients refused to sit at the table if he were seated.
Stu Ungar is recalled better for his abilities in hold’em poker but he always maintained that he was far more accomplished at gin rummy.
He defeated Doyle Brunson in the WSOP in Nineteen Eighty to become the youngest world champion. Because of his features that made him appear far younger than he actually was, he got the nickname, "The Kid".