When he stepped onto the gridiron at the end of the summer of 1963 to vie for the Detroit Lions' third-string quarterback job, Plimpton, then 36, could barely handle a snap. But his audacious book — an attempt to reveal the physical gulf between true athletes and the rest of us — won him literary fame. Plimpton, the co-founder of the Paris Review, later stepped into a heavyweight boxing ring, hit the links with Arnold Palmer and pulled off the literary trick play of penning an April Fools' Day Sports Illustrated story on a fictional pitching phenom. But Paper Lion remains the sports stunt for which this participatory journalist is best known.