The main basis for why Stu switched from gin rummy to poker was that he was a little too good at it. So good in fact, that no one possibly could equal him. Even the commonly called professionals who were supposed to be the most favorable at gin rummy were decimated when they competed against Stu. One of these gin rummy professionals was Harry Stein, called, "Yonkie". Mr. Stein was handed such a crushing beating at the hands of Stu Ungar that he apparently quit competing in it professionally and never showed up at a gin rummy tournament.
Certainly, with a distinction like that it was not very long before players became afraid of betting against mr. ungar. He could not find any matches and in his bleakness he began doing something no one had attempted prior. Stu presented beginning handicaps to potential competitors in the wish that they might play against him if they thought they held an edge. He deliberately started from a bad arrangement and one account has it that he even competed with a constant absconder. Mid game, he received warnings that the absconder was at it again but Stu Ungar assured that he was aware of the dishonestly and he would still come away with a win, which of course, he did.
The same problem followed Stu Ungar into sin city. He won so often that the casinos started requesting that he not to play in their respective premises anymore. The reason for it was that other poker room clients would not be seated at the table if Stu was playing.
Stu Ungar is recollected better for his achievements in holdem poker but he himself 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 champion. Because of his features that made him appear far younger than he actually was, he was nicknamed, "The Kid".