Persi Warren Diaconis is an American

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 mathematician

Mathematician

A mathematician is a person whose primary area of study is the field of mathematics. Mathematicians are concerned with quantity, structure, space, and change....

 and former professional magician

Magic (illusion)

Magic is a performing art that entertains audiences by staging tricks or creating illusions of seemingly impossible or supernatural feats using natural means...

. He is the Mary V. Sunseri Professor of Statistics

Statistics

Statistics is the study of the collection, organization, analysis, and interpretation of data. It deals with all aspects of this, including the planning of data collection in terms of the design of surveys and experiments....

 and Mathematics

Mathematics

Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...

 at Stanford University

Stanford University

The Leland Stanford Junior University, commonly referred to as Stanford University or Stanford, is a private research university on an campus located near Palo Alto, California. It is situated in the northwestern Santa Clara Valley on the San Francisco Peninsula, approximately northwest of San...

.
He is particularly known for tackling mathematical problems involving randomness

Randomness

Randomness has somewhat differing meanings as used in various fields. It also has common meanings which are connected to the notion of predictability of events....

 and randomization

Randomization

Randomization is the process of making something random; this means:* Generating a random permutation of a sequence .* Selecting a random sample of a population ....

, such as coin flipping

Coin flipping

Coin flipping or coin tossing or heads or tails is the practice of throwing a coin in the air to choose between two alternatives, sometimes to resolve a dispute between two parties...

 and shuffling playing cards.
Professor Diaconis received a MacArthur Fellowship in 1982, and in 1992 published (with Dave Bayer

Dave Bayer

Dave Bayer is an American mathematician. He is currently a professor of mathematics at Barnard College, Columbia University. He was math consultant for the film A Beautiful Mind, and also acted in it as one of the "Pen Ceremony" professors. He is also one of few people to have both an Erdős number...

) 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 playing cards must be riffle shuffled before it can be considered random according to the mathematical measure total variation distance.