The primary reason why Stu Ungar switched from gin to poker was that he was a bit too skilled at it. So good in fact, that no one possibly could stand up to him. Even the so-called experts who were supposed to be the most favorable at gin were blow away when they competed with Stu. One of these gin rummy masters was Harry Stein, called, "Yonkie". Harry suffered such a debilitating beating at the hands of Stu Ungar that he allegedly stopped competing in it professionally and never resurfaced at a gin rummy tournament.
Of course, with a reputation like that it wasn’t very long before everyone became shy of gambling against mr. ungar. He could find no matches and in his boredom he began doing something no one had done before. He began offering beginning handicaps to potential competitors in the wish that they might just compete against him if they thought they held an edge. He deliberately started from a bad arrangement and one account has it that stu even competed against a consistent cheater. Mid contest, he get warnings that the absconder was at it once again but mr. ungar assured that he knew of the chicanery and he would still actually win, which of course, he did.
The same problem followed Stu Ungar into Las Vegas. He won so often that the poker rooms began asking him not to compete in their casinos anymore. The reason was that other poker room customers would not sit at the poker table if he were playing.
Stu Ungar is remembered better for his achievements in holdem poker but he himself always said that he was a whole lot better at gin rummy.
He defeated Doyle Brunson in the WSOP in 1980 and became the youngest world camp. Due to his features that made him appear far younger than he was, he was nicknamed, "The Kid".