[2] He was widely considered the world's premier backgammon teacher, an original and clear-thinking theorist and one of its best players.

Magriel had several notable finishes in poker tournaments from the mid-1990s in Europe, playing in London, Paris and Vienna in Omaha, hold'em and seven-card stud events.

He won the €2,000 no limit hold'em event at the Aviation Club de France in September 2002, defeating a field including Pascal "Triple P" Perrault, Patrick Bruel and Simon "Aces" Trumper on the way to the €48,600 first prize.

The theory explains at which stages of tournaments expected value exists to make moves on other players, depending on the ratio between chip stack sizes and antes.

He has one son, Louis Fairchild Magriel (Louis being the name of all four grandfathers) by his third ex-wife, French poker player Martine Oulés[12] After receiving perfect College Board scores, he became, while an undergraduate, a fellow of the Courant Institute at New York University and later a National Science Foundation fellow at Princeton University with a primary interest in probability.