Offenses will typically exploit the flat in order to neutralize a strong attack from the defensive line in the middle of the field, and / or to manipulate a defense's strong pass coverage farther down field. For example, in flat route plays, quarterbacks pass the ball to a player (often a running back) in the flat in hopes that, while the pass has not gone downfield, the receiver (far from the middle of the field and not far downfield enough to worry about cornerbacks and safeties) will have a clear line for an after-the-catch run. If the quarterback hopes to throw farther downfield, the running back in the flat is an outlet receiver. If the receiver is accompanied by blockers, the play is called a screen pass.