in the nfl, as it happens every year.
Summary:
An OC or DC is a VERY different job than a HC. The OC and DC are in the weeds with matchups and playcalling, they have tunnel vision, and it is nearly 100% about the X's and O's. And some guys are really good at it. Its a specific skillset. They are good at seeing what they have on their squad, studying the film, seeing what the other guys have, predicting what they'll do in different situations, and exploiting as best they can. its pure Xs and Os.
The HC is much more of a figurehead and people manager more than anything.... making major gametime decisions and making sure all the departments are running well. Their main job is to decide WHO should be in the weeds doing the Xs and Os, who should be on the staff, and then managing the media and motivation and everything that comes with being the face of the franchise. A very specific skillset.
so, it actually doesn't make much sense that the pattern is for a really good OC or DC to move to HC. That may be taking a guy out of his skillset.
I think we can see lots of examples of that.