I would ask him if I could sit in and watch how a game plan is put together from start to end, to watch how the opponent is scouted, what tells and tendencies are picked up in video study, and how that is incorporated into the game plan along with tweaked call signs, cadence, and routes chosen, and why.
And watch how all of this translates into live action.
In this way I'd truly get an idea of how much of the execution is coaching related and how much of it is player-related (e.g., keeping cool in the heat of battle).
Of course I know what the answer would be... but, nice to fantasize.