This is an excerpt from Football's Eagle & Stack Defenses by Ronald Vanderlinden.
Zone Coverage Techniques
The advantage of zone coverage is that each defender is responsible for a predetermined area of the field. Playing zone defense allows a defensive back to have vision on both the ball and the receivers in his area, allowing him to quickly read a run or pass. Defensive backs must adhere to the following basic principles when in zone coverage:
- If two receivers are in one zone and the defensive back is being stretched vertically, the defensive back should always cover the deepest threat. He should break up to the short route when the ball is thrown.
- If a defensive back is responsible for an underneath zone, he should have vision on the quarterback's throwing arm. The defensive back should break on the ball when the quarterback's off hand leaves the ball as he prepares to throw.
- In zone coverage, the defense wants to make the quarterback throw the ball in front of the defense.
- When a defensive back is responsible for a deep zone, he should break only when the ball is thrown. He should also make sure he doesn't break forward prematurely on a quarterback's pump fake when the receiver breaks off a short route and then turns upfield vertically.
- Zone defense allows defenders to read the quarterback's eyes and shoulders. Defenders should be aware that the quarterback can only throw in the direction his off shoulder is pointing.
- If the quarterback scrambles, the secondary's job is to play the pass until the quarterback crosses the line of scrimmage. Deep defenders should stay deep.
In addition to these basic principles, defensive backs must be able to respond to several other key indicators that will help them read the upcoming play. Recognizing the backfield action will help defensive backs anticipate the potential play and the pass routes from the receivers in their zone. When the quarterback takes a three-step drop (see figure 15.7), the secondary should read a quick passing attack and should be ready to break on the football when it is thrown. The deep defenders should be alert for the possibility of a quick pass fake by the quarterback and a go route by the receiver.
When the quarterback takes the ball off the line of scrimmage, he may hand the ball off to the running back (see figure 15.8), or he may fake the run and execute a play-action pass. The secondary should feel the tempo of the offensive line to help them with their run-pass read. The secondary players who have responsibility for a deep zone should backpedal, maintaining deep leverage on any receiver in their area, until they are certain the play is a run. The primary force players should buzz their feet and hold their position until they recognize a run or pass.
When the quarterback drops straight back (see figure 15.9), the secondary defenders who have responsibility for a deep zone should backpedal and maintain deep leverage on any receivers in their area. The primary force players should bounce and hold their position until they recognize the route being run in their area. However, versus four vertical pass routes, the flat defender will sink and carry the number two receiver vertically.
The secondary should always be aware of an abnormal split by a receiver. The split can be either wider or tighter than normal. Certain splits by the receivers will correspond to particular routes that the receivers run. Studying game tape can give a defensive back an edge when reading how a team will use the split of a receiver to set up a certain run block or pass route. Defenders need to communicate what they see.
The alignments, reads, and techniques used by the defensive backs in Cover 4, Cover 3, and Cover 2 are detailed in the following sections. Cover 4 and Cover 3 incorporate elements of the techniques used in Cover 5, Cover 2, and Cover 44. Cover 4 is a two-deep coverage to the boundary but a 44 coverage to the field. Into the boundary, the corner's technique is a deep-one-half defender but four yards off the high school hash. Cover 3 is similar to playing Cover 5 for the strong safety, but the free safety is a deep-middle-third defender. Cover 2 has two deep defenders, each responsible for one half of the field. This coverage has five underneath defenders. The corners are rolled up and are responsible for the flat zone. The Sam and the eagle linebackers are responsible for the curl zone, and the inside linebacker is responsible for the middle hook zone.
Learn more about Football's Eagle & Stack Defenses.