In 1979, he published the authoritative Theory of Blackjack: the Compleat Card Counter's Guide to the Casino Game of 21, a book that explored the probabilities of every conceivable situation in the game and established that players could gain an edge over the house by keeping track of cards as they were played and placing big bets when the remaining deck was rich in tens and face cards.
Although much of the groundwork had already been done 17 years before in Edward Thorp's Beat the Dealer, a book credited with transforming the game into a high-roller's favourite that now accounts for almost half of casino table-game revenues, Griffin's tome illuminated the ways to win. "The Theory of Blackjack is a fundamental contribution to our understanding of the game," recommended Thorp himself.
The clarity of Griffin's step-by-step explanations of complex calculations, and the humour with which the subject was couched, delighted card-sharps and mathematicians alike, and Griffin undertook lecture tours of casinos and gambling conferences around the world, astonishing seasoned players with his ability to keep six separate running tallies in his head.
Griffin had never played the game until an evening in 1970 when, to gain experience for a proposed course on gambling mathematics, he paid a visit to Las Vegas, was roundly fleeced, and vowed to get his revenge.
Although his book was reprinted six times and he followed it up with a sequel, Extra Stuff: gambling ramblings (1991), Griffin maintained that blackjack was too boring to play for the long stretches that profitable card-counting requires, and he was resigned to never making his fortune as a gambler.
His aptitude for mathematical problem-solving was in his blood; one of his grandfathers had been a prominent mathematician, and his father ran an insurance company. A native of New Jersey, he grew up in Williamsport, Pennsylvania, graduated from Portland State University, and received a master's degree from the University of California.
He taught at California State University, Sacramento, from 1965 and became Professor of Mathematics in 1977; there, his precise time-keeping habits allowed his colleagues to set their watches by the times he arrived at his office or picked up his post.
As a man whose idea of a publicity photograph was to pose on an elephant, his mathematical prowess never overshadowed his sense of humour. He would steer any conversation towards mathematics but was always understanding towards anyone who found it difficult to grasp the laws of probability governing why, for instance, in any random group of 35 people, the odds are overwhelming that at least two will have the same birthday.
Peter Griffin, mathematician: born 19 July 1937; Professor of Mathematics, California State University, Sacramento 1977-98; married; died Sacramento, California 18 October 1998.