There is really no such thing as the best coach. You would have to be the winningest coach, best at clock management, best offensive coach, the best defensive coach, the best motivator, the best best recruiter, the best at player development and on a on. And all those aspects can be broken down even further as in best zone coach coach, best man to man coach, etc. The whole concept of best coach is nonsense.
I know this. We have a very good coach. But arguing about who is the best coach is as meaningful as arguing how many angels can fit on the head of a pin.