Headlined by Bill Belichick at North Carolina, the ACC has three ex-NFL head coaches leading its football programs this fall.

Bill Belichick’s UNC players have dismissed claims about his 24-year-old girlfriend’s “controlling” involvement with the team. Belichick, 73, got caught in a controversy after fans speculated that his girlfriend, Jordon Hudson, was displaying “controlling” behavior toward the former NFL coach in an interview.

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.