This may be stupid, but it just dawned on me that I have no idea what goes into calling plays in real life. In video games I just use the recommended plays and it's pretty easy. 

So do the coaches have an "Ask Madden" type cheat sheet or do they just call whatever play seems good at that time? I'm sure there are hundreds of plays so I'm intrigued as to how they narrow down their options. With the new up-tempo offenses running plays every 15 seconds I think it would be impossible to go through every play to think of the best one. 

Furthermore, what exactly goes into calling the play communication wise? Does Warinner call the play and that's it, or do him, Beck and/or Urban all come up with a call together?