Eli5: what does a quarterback look for when teams get to the line of scrimmage? And what does he do before the snap?

Question

Eli5: what does a quarterback look for when teams get to the line of scrimmage? And what does he do before the snap?

In: 2

Answer 1

He’s scanning the defense to see how they are positioning themselves and contrasting that with the play that was just selected in the huddle.

At the line of scrimmage he is looking for movement by key defensive players that might indicate whether the called play needs to be altered (for example, if a run play is called, but the defense is bringing additional players close to the line of scrimmage).

After the snap, he has his “check-downs” to run through for any pass play.