It all depends on the coach and how much he wants to delegate. Game film does alot of that and it also depends on the freedom of the QB. Gruden sure as hell wouldn't allow Gradkowski to call an audible. He would hardly let Simms do it. Brad Johnson and Griese he trusted a tad bit more.The QBs first job is to read the defense and look for favorable match ups. If he sees something he can take advantage of he can call an audible and change the play at the line.