Winning or losing. Do I get to choose?

As a young man I would often watch sports games with my grandfather. My notion of a coach was that they're only to: call plays, regulate who played and who sat on the bench, and yell at the players when they played poorly. As I have aged over the years, I have come to the realization that a coaches job is much more in-depth.
What qualifies a coach to have a fan say "He's a good coach" to another sports loving extremist. One could say that a good coach is: able to call scoring plays, but isn't it the players job to get across the end zone without mistake? Or that the coach puts in the players that will put points on the board, but isn't it also under the players control to hustle and make a fast break? So I guess Average Joe could do a coaches job, which would make all coaches the best and the worst at the same time.
If you take a look at the last example of a "good coach" the truth of the matter is that the player really doesn't choose to be "on" on game day. By positive reinforcement, the true meaning of a good coach, the coach is able to control the players thought process and ultimately their performance on the filed.