RANDOM COIN FLIP PROFESSIONAL

Martin Gardner, the publication's mathematical games columnist, touted those submissions as two of the 10 best card tricks ever invented.

RANDOM COIN FLIP PROFESSIONAL

Right before leaving home to become a professional magician, Diaconis had managed to get two of his card tricks published on the puzzle page of Scientific American magazine. Fortunately, he had a few aces up his sleeve. With bare-bones mathematical skills and no high school diploma, 26-year-old Diaconis was a long shot for a spot in Harvard's graduate program in statistics. 'Barely six to nine months after he struggled with my advanced calculus course, he was applying to the finest graduate schools to continue his study,' says D'Aristotile, who has taught probability courses at Stanford the past four summers. 'He was nothing special at the time.'īut D'Aristotile, now a math professor at the State University of New York-Plattsburgh, saw that the kid had chutzpah. After his first semester of advanced calculus, Diaconis was 'very raw,' recalls Tony D'Aristotile, who taught the course.

He performed magic tricks during the day to pay his way through school. He was 18 at the time.Īt 24, Diaconis began taking evening math classes at the City College of New York. At a friend's suggestion, he bought himself a copy of William Feller's textbook An Introduction to Probability and Its Applications but couldn't read it because he didn't know calculus.

To bet strategically, one had to calculate the odds that a die with one-hundredth of an inch shaved off an edge would tumble out of the box on any given side. At a certain crooked Caribbean gambling house, Diaconis tried devising schemes to prevent him and other globetrotting magicians from getting cheated.ĭiaconis had no idea this mission would prompt a career shift. Having left his New York City home at 14 to travel with a sleight-of-hand expert named Dai Vernon, the high-school dropout spent the next decade honing his skills in magic. (They didn't.) Visiting the company's Las Vegas showroom was a homecoming of sorts for Diaconis. For example, people had long supposed that a few shuffles were sufficient to randomize a deck of cards - until 1992, when Diaconis and Columbia University's David Bayer proved that thorough mixing requires seven shuffles.Ī decade later, in 2002, a large manufacturer of card-shuffling machines for casinos summoned Diaconis to determine whether their new automated shufflers truly randomized the deck. Diaconis had good reason to suspect that surprising truths lurk beneath common assumptions. 'You know, everybody knows it's true, and then we prove it. 'Mathematicians are always doing that,' he says. Could a simple coin toss - used routinely to decide which team gets the ball, for instance - actually be rigged?ĭiaconis set out to test what he thought was obvious - that coin tosses, the currency of fair choices, couldn't be biased. Now a Stanford professor of mathematics and statistics, Diaconis has turned his attention toward simpler phenomena: determining whether coin flipping is random. In the mid-1970s, the upstart statistician exposed some key problems in ESP research and debunked a handful of famed psychics.

In 1962, the then 17-year-old sought to stymie a Caribbean casino that was allegedly using shaved dice to boost house odds in games of chance. Persi Diaconis has spent much of his life turning scams inside out. JMagician-turned-mathematician uncovers bias in coin flipping Magician-turned-mathematician uncovers bias in coin flipping | Stanford News Release

Random coin flip