After 29 years as an NFL head coach, Bill Belichick is headed back to college, where he’ll be the head coach of the North Carolina Tar Heels. While this is a program known far more for its basketball prowess than football, no one is more proven as a leader than coach Belichick.

But Belichick, widely regarded as one of the greatest—if not the greatest—NFL coaches of all time, is already noticing differences between players at the college and pro level. And it goes beyond the obvious age and skill differences that one would assume exist between the levels of football.