When a cornerback is attempting to jam a receiver, he is trying to disrupt the receiver's route at the line of scrimmage. Many routes are precisely coordinated between the quarterback and the receiver, to the point that a quarterback may throw the ball without looking, knowing his receiver will be in an exact spot after a certain time. Jamming will disrupt the timing between the two, which provides the defense with extra time to sack the quarterback (sometimes called a "coverage sack"), or force an ill-timed throw that misses the target. In addition, a proper jam allows the safety or linebacker to provide stronger run support because he then has more time to drop back into zone coverage in the event of a pass. In other words, he has been granted more time by the corner to recover from his mistakes if he anticipates a run when in fact the play is a pass.