Before paul hoffman came along, Paul Erds was famous only among mathematicians. Erds (pronounced air-dish) was an impish, amphetamine-swallowing number theorist from Hungary who lived out of a shabby suitcase, gave nearly every waking moment to mathematics and published more than 1,400 papers, making him one of the most prolific mathematicians of all time. Colleagues in dozens of countries adopted him as their itinerant "Uncle Paul" and saved up their thorniest math problems for his visits. But after Hoffman profiled him in The Atlantic, Erds' renown grew logarithmically, so much so that The New York Times felt obliged to run a 1,200-word obituary on his death in 1996.

Erds was the kind of subject magazine writers kill for: brilliant and eccentric, with a colorful history and a penchant for advertising his irreverent philosophy of life. But to evoke in readers the same mixture of amusement and awe Erds' colleagues felt toward him, while simultaneously explaining Erds' lifelong love for numbers, required a writer with Hoffman's special literary and intellectual skills.