"What we're talking about, basically, is you have a play call, you have a pattern that develops, and the guy has to read, sometimes whether the middle of the field open, whether the middle of the field is closed, as to which side he's going to throw the ball to," he said. "So that's one of the things that we think about. Other times you're just trying to limit the side of the field he's going to throw the ball to, he's reading some kind of a high-low, which is a little bit easier for him to do."