Cornerback
A cornerback's skill set typically requires proficiency in anticipating the quarterback, backpedaling, executing single and zone coverage, disrupting pass routes, block shedding, and tackling.
Cornerbacks can be anywhere on the defensive side of the line of scrimmage at the start of play, although their proximity, formations, and strategies are outlined by the coaching staff or captain.
Examples of cornerbacks in the NFL are Jalen Ramsey, Patrick Surtain II, Marlon Humphrey, Jaire Alexander, Sauce Gardner, L'Jarius Sneed, and Charvarius Ward.
When a team is using zone coverage, some areas of the field require special attention when defending against specific pass plays.
He will base his decision on past experience, game preparation, and a sound comprehension of his teammates strengths, abilities, and tendencies.
For example, defensive coordinators may favor a tendency to play a less aggressive containment style zone coverage during wet or slippery field conditions to avoid problems associated with over-pursuit (when a defender takes a poor angle on a ball carrier and cannot redirect in time due to poor footing).
In the Cover 1 defense, one defender—normally a safety—plays deep zone downfield, providing security over the top and freeing the other safety to rush the line of scrimmage or drop back into coverage.
In Cover 2, the cornerback is usually responsible for "containment", meaning that he is tasked with preventing any eligible receiver or ball carrier from running between him and the sideline.
He funnels receivers toward the middle of the field and may physically "jam" them within five yards of the line of scrimmage in order to disrupt their assigned routes.
This allows the strong safety to address a full range of duties depending on what reads he makes coupled with the coverage called.
These duties may simply include single or zone coverage, being a quarterback spy, providing extra run support in short yardage situations, or to stunt or blitz through a gap or from the end.
Although these are forms of single coverage, more often than not his responsibility is usually limited to an initial jam and funnel with a subsequent drop back into the "void".
However, your basic garden variety 2 Deep Zone usually employs the two safeties to share half the field responsibilities, with the two corners funneling.
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.
Therefore, it is vital that a cornerback execute a proper funnel or jam to allow safeties and linebackers enough time to return to their zone responsibilities in the event of an unforeseen pass play.
These types of routes are difficult to stop in the red zone because this area is usually congested with bodies colliding, crossing, and weaving in different directions.
To avoid this, it is often favorable for cornerbacks to either: "switch" assignments, where he will agree beforehand to trade assignments with one of his fellow defenders if the receivers criss-cross as the play begins, or alternatively, if a corner may instead line up very close to the receiver at the line of scrimmage to force or "jam" him toward the sideline (outside) without violating the 5-yard no-touch rule.
Although terminology for single coverage can vary, a few generic terms have been included to establish a general understanding of cornerback philosophy and how his function relates to the rest of the defense.
The idea is to disrupt the coordination necessary for short routes, which leads to drops or poorly thrown passes stalling the drive.
Corners must also hope the receiver does not change directions when it is time to sneak a peek at the quarterback in effort to discover where the ball is.
