Sun had spent, according to the New York Times magazine, hundreds of hours memorizing tiny flaws in purple Gemaco Borgata playing cards.
She purchased souvenir playing cards from the Borgata, identical to the ones used on the casino floor save for holes punched in the center. She discovered that patterns on card backs, designed to be symmetrical, were not perfectly so. Sun trained herself to identify aberrations along the left or right margins of the card backs, no wider than 1/32 of an inch, the Times reported. (“Sun’s mental acumen in distinguishing the minute differences in the patterns on the back of the playing cards is remarkable,” Hillman noted.) So prepared, she helped Ivey on his way to millions.
It was part of an elaborate revenge plot to win as much as possible from a casino chain she had failed to pay a debt to which resulted in her being thrown in jail where she was treated poorly.