He left the NFL for mathematics – and just made a big breakthrough

> After retiring from the Baltimore Ravens, John Urschel said he looked forward to being known as "that mathematician who used to play football."

> A paper called “On the Growth Factor of Random Matrices” would not normally attract headlines. But when it was posted on social media this week by another researcher in the field, online observers took note for an unusual reason: The author, John Urschel, had a previous life as a professional football player for the Baltimore Ravens.

> Urschel, 35, is now a tenure-track professor at the Massachusetts Institute of Technology. He quit football in 2017, partly over concerns about sustaining the kind of traumatic, degenerative brain injuries that have scarred a generation of players in the National Football League. He went on to finish his PhD in mathematics, wrote a memoir and now says he’s enjoying life as a regular mathematician in the academic sanctuary of Cambridge, Massachusetts, far from the spotlight.

His paper: https://arxiv.org/abs/2610.06785