From what I've read, his overall football knowledge is off the charts, which I'm sure causes other coaches and many people in the profession to think highly of him. But knowledge alone doesn't get you more wins.

I think it's like this: only a handful of coaches get more wins than an average coach would. Guys like Saban and Harbaugh are in that elite group — they've got such a unique combination of smarts, charisma, talent, and drive that they deliver more wins than an average replacement would. And then there are a handful of guys who are so bad that they clearly do worse than most coaches would.

But other than those small groups on either end of the spectrum, the hard reality is that the vast majority of coaches are totally replaceable. I think there are dozens of coaches out there, maybe hundreds if you looked across all levels, who could do just as good a job in the NFL and at UCLA as Chip Kelly.