A whole article about this kind of thing without a mention of the dork in Orlando with a fax machine? In fact, Georgetown and its B-school are listed here as the academic source, which has to infuriate the dork.
It says that the pipeline to NFL head coach often goes through offensive coordinators, offensive quality control coaches, and quarterbacks coaches. And those are heavily white. In contrast, where you see blacks dominate in the NFL assistant coaching universe are running backs coaches and defensive secondary coaches. Those are not good pipelines to head coaching.
Because we’re versed in HBD, we know why the QB position is heavily white and RB, CB, FS and SS are heavily black. Because the QB position rewards intricate forward thinking and planning, and RB and the defensive secondary reward speed and impulsive reaction. So it stands to reason why QB coaches are white and RB and defensive secondary coaches are black.