John Urschel started 13 games on the offensive line for the Baltimore Ravens. Then he read one study and retired at 26. Today he is an assistant professor of mathematics at MIT. Urschel was a fifth round pick in 2014 out of Penn State. Guard and center. 40 games, 13 starts, a real NFL career by any honest measure. Most fifth rounders never get on the field at all. But the football was always the second thing. He got his bachelor's and his master's in math at Penn State in a single year, 2012 to 2013. While playing Division I football. He co-authored a paper on graph theory as an undergraduate that is now known in the field as the Urschel-Zikatanov theorem. In 2013 he won the William V. Campbell Trophy, which people call the academic Heisman. So he was doing both. In January 2016, while he was still an active NFL lineman, he enrolled in the PhD program in applied mathematics at MIT. Practice in Baltimore. Coursework in Cambridge. Straight A's in his first four doctoral courses. Then came the hit. In training camp in 2015 Urschel took a concussion. And what scared him was not the headache. It was that for a while afterward, he could not do math the way he used to. The one thing that was actually his, the thing football was supposed to be the hobby next to, got slower. He came back. He played the 2016 season. And then in July 2017 the JAMA study came out. Researchers had examined the brains of 111 deceased NFL players and found signs of CTE in 110 of them. 110 of 111. Two days later, Urschel retired. He was 26 years old. "This was actually a serious, serious concern of mine," he said. Think about what that actually costs. He was on a rookie deal with starts on tape and years of earnings in front of him. He traded all of it for a graduate student stipend and a desk. Then he went and finished the thing. He earned his PhD from MIT in 2021 under Michel Goemans. His dissertation was titled Graphs, Principal Minors, and Eigenvalue Problems. Spectral graph theory and numerical linear algebra, which is the kind of math that quietly runs underneath machine learning and network analysis. In the fall of 2023, MIT hired him onto the faculty. The former Baltimore Ravens offensive lineman is now on the other side of the desk at one of the best math departments on the planet. He wrote a book with his wife Louisa Thomas called Mind and Matter: A Life in Math and Football. Forbes put him on the 30 Under 30 list in science. Dartmouth gave him an honorary doctorate in 2024. And when he talks about what he actually wants for people, he does not talk about football or even about proofs. "Being capable of thinking quantitatively, it's the single most important thing." Here is the honest counterpoint. Urschel got to make that choice because he had an elite fallback. Most NFL players do not have an MIT acceptance letter waiting when the brain scans get scary. For most guys, walking away at 26 means walking away into nothing. That is the real story of CTE in the league and it is a lot grimmer than this one. But it does not make what he did smaller. He was 26, healthy, starting, and getting paid. He read the number 110 out of 111, decided his brain was the asset, and went and used it. He kept the thing the game was most likely to take. For more stories like this, follow us on any platform @thesportsontap