Professor Diaconis achieved brief national fame when he received a MacArthur Fellowship in 1979, and again in 1992 after the publication (with Dave Bayer) of a paper entitled "Trailing the Dovetail Shuffle to Its Lair" (a term coined by magician Charles Jordan in the early 1900s) which established rigorous results on how many times a deck of 52 playing cards must be riffle shuffled before it can be considered "random enough." Diaconis established that the deck gradually increases in randomness until seven shuffles, after which the thus-far experienced increase in randomness stops significantly increasing. At least seven shuffles, for reasons made precise in the paper, is what casinos should use.
Diaconis is a colorful character. He left home at 14 to travel with sleight-of-hand legend Dai Vernon, and dropped out of high school, promising himself that he would return one day so that he could learn all of the math necessary to read William Feller's famous two-volume treatise on probability theory, An Introduction to Probability Theory and Its Applications. He returned to school, learned Feller, and became a mathematical probabilist.
A Reliable Randomizer, Turned on Its Head; In the Physics of a Coin Toss, It Turns Out, There's No Such Thing as 50-50 Odds
Aug 02, 2009; Coin tosses are a classic metaphor in economics for randomness. For instance, in his book about market efficiency, "A Random Walk...