NFL Defensive Strategies Explained

Successful teams in the NFL deploy a variety of defensive schemes, defensive strategies and defensive formations in order to be successful. The thing is, few announcers or broadcasters even take the time to truly explain the differences between all of them. Even some of us “real” NFL fans may struggle to understand what some fancy name really means when applied to an NFL defense. Let's explore some of the frequent defensive formations and strategies used by all NFL teams and coaches.
Nickel Pass Coverage – When an NFL defense is trying to stop a passing attack or is expecting a sure passing call on a down setting such as 3rd and 20, commonly they will deploy an extra defensive back. In a base defensive formation there are four defensive backs, two corners and two safeties. In nickel, a fifth defensive back (hence the word nickel) comes onto the field, replacing either a linebacker or a defensive lineman. You can commonly see arrangements such as a 4-2-5, where a team started in a 4-3 base formation and traded a linebacker for a defensive back, or a 3-3-5, putting a defensive back in place of either one depending on whether you started from a base 3-4 or base 4-3.
The extra defensive back that comes in, usually a cornerback is known as the nickel back of the team. He's the guy that comes in specifically for these packages and is below the depth chart as compared to the starting corners. If a team relies heavily on their passing attack and three or four wide receiver formations, an NFL team can switch to a nickel formation as their base package the entire game.
Dime Pass Coverage – OK this is easy. A nickel formation in the NFL has five defensive backs. So a dime must be the rarely seen 10 defensive back formation, right? Well, I guess dime was just easier than “nickel + penny”, because a dime pass defense formation involves the use of six defensive backs, or one more than the nickel. The dime comes out usually when one team is trailing and playing catch up late in the game, or when time is tight leading up to the half and the defense is trying to prevent a big play. With six defensive backs on the field, sometimes two linebackers are replaced, although two linemen or a combination of one lineman and one linebacker can be replaced as well. The dime defensive formation is vulnerable to underneath routes and the running game, which the defense is fine conceding to prevent a quick, deep gain.
Quarter Pass Coverage – Well we know there can't be 25 defensive backs in this one, so yes, the quarter pass coverage scheme sends seven defensive backs onto the field. The quarter formation is never a base defense but is brought in for a few plays at a time in certain situations. Sometimes even speedy, lengthy wide receivers will take the field as extra defensive backs for a team. The quarter defense is often used when a team is said to be using a “prevent defense” as in, preventing a deep completion. It does however allow for smaller gains, but the defense is only used in time situations when underneath gains shouldn't have any affect. When a team is trying a Hail Mary pass play at the end of a game or half, for example, is a common – and one of the rare – time to see the quarter pass coverage formation.
8 Men in the Box NFL DefenseEight Men in the Box – In typical NFL defensive formations, there will be seven men up front, or “in the box”. “In the box” refers to the area of the field close to the line of scrimmage and in the center. Depending on the formation, that may be four defensive linemen and three linebackers, three linebackers and four defensive linemen or other, more exotic combinations. When a team is either expecting a running play, or is trying to stop a team with a strong running game, the defense will change formation and put an eighth man in the area of the field known as “the box”. Typically, one of the deep safeties will leave his post and come forward. Although sometimes an extra linebacker or linemen could be brought in from the sideline in place of a defensive back, making an even tougher defensive front to run against.
Zone Blitz – I shouldn't assume that all NFL fans know what a blitz is, but if you've gotten this far I will assume you don't need too much help explaining that. A blitz is any defensive play where an extra defensive player, besides the linemen, goes after the quarterback. Typical blitzes include a cornerback blitz, where one of the cornerbacks rushes the quarterback from the outside of the field at the snap. One of the linebackers or a safety will move over to cover his man. The zone blitz is a little bit more complex than that and serves the purpose of not just pressuring the quarterback, but also confusing him and leading him to make a mistake.
A typical zone blitz
In a zone blitz, a linebacker who seems to be dropped in pass coverage will end up rushing the quarterback. A quarterback then usually expects that part of the field to be open, but with a zone blitz, a defensive lineman has actually dropped back a few yards into that space to cover where the linebacker originally was. So if the defense doesn't get the sack they were going for, they have a plan B of getting an interception. NFL defenses love using zone blitzes against rookie NFL quarterbacks. When you are watching a highlight show and see that big ole 330 lb lineman hauling in an interception, chances are he dropped back into pass coverage from a zone blitz.
Defensive Stunts – The best offensive lines in the NFL are the best not because of size, but because of knowledge. They know who their assignments are, which players they need to try to block and what the overall offensive blocking strategy they are following is. A stunt is a way to turn all of that upside down and confuse the offensive linemen into missing a block. Whereas a blitz is effective by sending more men at the quarterback than the line will be able to block, a stunt uses the same amount of players but sends them in different ways than expected. Delving into some more terminology here, a “gap” is the space between offensive linemen. The A Gap is between a center and the guards, the B Gap is between the guards and tackles and the C gap is beyond the tackle, sometimes between a tight end. On a normal play, a defensive lineman rushes straight forward into whatever gap he is lined up against. For example, the right defensive end will rush on the left C gap and the left tackle will try to block him.
Now, design a common stunt, and the right defensive end rushes toward the center of the line, in the B Gap, and the defensive tackle next to him rushes to the outside portion of the line and the C Gap. If done effectively and right at the snap, the offensive linemen can have a moment of hesitation or confusion that enables one of those players to slip by and create some pressure. Not only does a defensive stunt confuse, it can also create mismatches. Defensive ends are usually very quick, and a tackle must have the footwork to keep up with him. However, guards and centers are usually not known for their fleetness of foot. For all of the reasons, a defensive stunt is an effective means of pressuring a quarterback.
Quarterback Spy – I'm sure most NFL defensive coordinators pine for the old days, when you didn't have to worry about anything a quarterback could do, besides pass the ball. And if you're playing a classic, standing tall in the pocket quarterback such as Peyton Manning or Carson Palmer today, you still don't. But a new type of quarterback emerged, led by Steve Young, John Elway and Randall Cunningham, and truthfully, before all of them was the one of a kind Fran Tarkenton. These guys could take off down field for a first down just as easily as they could throw the ball for one. Now of course, from Vince Young to Donovan McNabb to Michael Vick while he was still playing and a dozen others, running threats at quarterback are all around the NFL.
The quarterback spy was created to combat just this. The job of the quarterback spy is just that, to spy on the quarterback, follow him around the field, and prevent him from running through a big hole once he decided not to pass. The job will commonly go to a speedy linebacker, one who can keep up and even outpace the running quarterback but still be strong enough to bring him down handily.

These are just some of the basic defensive strategies seen in the NFL. Every NFL team in the league will have all of these defensive calls in their playbook, it's just a matter of how often they bring them out. If you're looking to boost your NFL knowledge even more, read the corresponding Offensive Strategies article we have here at Discount Football Merchandise, or some of the more specific strategy articles pertaining to one offense or defense specifically.