What changed on fourth down? Why the NFL is headed for a golden era of analytically driven four-down offense

Social media lit up on Sunday night in the moments after the Baltimore Ravens converted a fourth-down run to seal an exhilarating 36-35 victory over the Kansas City Chiefs. Amid the flurry of "WOWs," shock emojis and celebratory GIFs was a tweet from Michael Lopez, the NFL's director of football data and analytics. After watching Ravens coach John Harbaugh make a difficult decision from his team's own 43-yard line, sending quarterback Lamar Jackson up the middle for two yards, Lopez posted the headshot of a man that only his followers and a handful of other devotees to football analytics would recognize.

Pictured was Daniel Stern, the Ravens' football research coach and the man responsible for giving Harbaugh the information he needs to make the kind of choices that are taking over NFL game strategy.

"It was basically a win for analysts everywhere," Lopez said this week. "As a member of the league office, I'm a fan not of one team but all 32. Whether or not they converted makes a difference in the optics, but just the fact that there was enthusiasm about going for it in that situation, that was the biggest thing from my perspective."