Now in paperback comes the first and authorized biography of Stuey Ungar, the greatest card player of all time, who was backed by the Mob in New York before moving to Las Vegas where he won the World Series of Poker three times, then died mysteriously in a seedy motel on the Vegas strip at the age of 45.

He was the Jim Morrison of the casino, a legend before he was of legal age. Stuey Ungar, the son of a Jewish bookie on Manhattan's Lower East Side, dropped out of high school to become an underground card-table sensation, eventually taking out every top gin-rummy player on...