Understanding The Cover 3 Defense In Football
You’ve probably heard of several football defense formations. One such famous defense is the cover 3 defense. It’s a great defense with a good balance to work both against the run and pass plays.
So, what exactly is a cover 3 defense in football? This is a defensive formation with three deep defenders and four more defenders underneath. It’s a defensive cover for the secondary and linebackers. The three deep defenders cover respective thirds of the field.
Looking to learn more about the three cover defense? Keep reading below.
What is Cover 3 Defense in Football
A cover 3 defense in football is a zone-based type of defense where seven players drop and take distinct positions. The defense formation employs three defensive backs covering the deep thirds of the field. There are also four defenders underneath.
Overall, the 3 cover defense is widely used for deep passing plays. But, it does work against run plays due to the strong safety lining closer to the scrimmage line and linebackers.
The idea behind the defense is to have a good balance between run and pass plays. The three backs are usually called the “three-deep,” while the four are called the “four-under.”
This great balance is the reason many youth teams in the youth widely use it. However, the defense can be used throughout the leagues, with the Seahawks using it all the way to the Super Bowl finals.
Keep reading to learn more about the defense positions.
Positions Needed In Cover 3 Defense
Just as the name suggests, the 3-cover defense features three defensive backs in the deep. In the deep, there are three positions.
First, we have two cornerbacks that take right and left thirds of the field. The third player is a free safety and covers the middle of the thirds. He’s referred to as a free safety because he can roam freely in the backfield.
Next, we have the four positions in the middle and short zone. Here, we have the strong safety position, a nickel (also known as the open-side linebacker), and two linebackers in the middle.

A stronger safety line near the line of scrimmage on the side with an extra-lineman, hence the name strong. He stays on the stronger side, taking the flat/curl responsibility.
Overall, in the 3 cover defense, you’ll have seven players dropping deep and taking different positions. Three defensive backs will take three positions in the deep backfield, while four underneath players take positions in the short and middle.
Who Should Use The Cover 3 Defense
Now that you know the 3 cover defense, you need to know which team should use it.
The good thing about this defense formation is that just any team can use it. It’s a pretty versatile defense that can provide coverage against the run-and-pass plays.
It works perfectly on early downs since it’s effective against run-and-pass plays. On the first and second downs, offenses are quite unpredictable. However, this isn’t the case on the third down.
Overall, this is a defensive formation for linebackers and defensive ends. It’s quite popular in youth settings and the NFL. The four underneath players provide the necessary pressure to protect the 3 deep players.
Depending on the opposition, any team can use the 3 cover defense with a few tweaks in the alignment. More skilled teams can create an out-of-base formation with blitzes and wrinkles.
Strengths Of The Cover 3 Defense
So, what are some of the strengths of the 3 cover defense that makes it outstanding?
First, the defense is quite simple and easy to teach. You just need three deep defenders taking zones in the backfield. The defender doesn’t do much, whether the offense plays a pass or a run play.
They simply need to take responsibility for their respective zones.
Secondly, the three-cover defense is quite effective against deep balls. We all know how big passing plays can end a game. Luckily for this defense, the three defenders dropping deep help protect against deep passes.
Teams can be sure of defending well against over-the-top passing plays.
It’s also quite versatile, defending against run-and-pass plays. Unlike other defenses where teams must shift players backfield depending on the offense, the cover 3 defense works well.
You can have the three defensive backs taking their respective zones, no matter the kind of play.
The cover three defense is easily adjustable. Teams can tweak it with ease to match any opposition. This is possible as the strong safety line is similar to linebackers, leaving little room for runs and short passing plays.
Weakness Of The Cover 3 Defense
However, this doesn’t mean the defense lacks weaknesses. The defense is also susceptible to play actions. It only needs an offense capable of tricking the defense into making the wrong move.

The offense can fake a play and make the cover 3 defense take a step forward, leaving spaces deep. Teams can easily make big plays over the top with play-action.
This usually happens when a defense is tricked into thinking the offense wants to play a run. When they think, the defense will take a step or two forward as opposed to backward. This then provides offenses with opportunities for big plays.
The cover three defense is also susceptible to spread formations. You can have the offense spread formation play where wide receivers and linebackers take advantage of three defensive backs. When teams implement the spread formation correctly, they can create holes in the defense.
Lastly, the cover three defense easily offers yards to opposition teams. This is usually the case with cornerbacks first taking a step back from the scrimmage line.
As they take a step back, they provide opposing wide receivers a few yards to roam freely. The yards gained are pretty minimal but still a benefit to the opposing team.
In the end, the small yards can add up and sustain a drive into your defense. The last thing any defense would want in a football game is to provide the opposing team with extra yards.
How To Run The Cover 3 Defense
So, how do you go about running a cover-three defense? Below, I’ll take you through the stages of running a cover-3 defense.
Stage 1: Set up the defensive line
First, you need to set up a defensive line. In a cover three defense, a defensive line is similar to most base defenses.
Here, you need three defensive linemen to put a lot of pressure in the backfield. Their main role is to run to the scrimmage line and disrupt play as much as possible.
In a three-cover defense, teams experience more blitzes than in a two-cover defense. You need to have the four defensive linemen applying as much pressure as possible in the line of scrimmage.
Have the two defensive tackles lining up anywhere between the center and the offensive tackle. Have the bigger of the two lining between the guard and the center. The bigger player is considered the nose tackle.
This will leave the other defensive tackle shading either the right or left shoulder of the offensive tackle.
Overall, you’ll have the defensive linemen using stunts and curls between the defensive ends and defensive tackles. The aim is to cause as much disruption on the line of scrimmage.
Stage 2: Set up the Linebackers
The next step in setting up a cover-three defense is to position the linebackers. Here, we have the middle linebacker Mike, strong-side linebacker Sam and weak-side linebacker Will.
These three will provide coverage on the quarter of the field when you consider the field width. The three players are tasked with stretches 5 yards from the line of scrimmage or a few yards from where the line is.

Both Mike and Will line up closer to the line of scrimmage. They help provide coverage against runs from the offense. With the stronger depth lining up in a similar depth to the linebackers, Mike and Will have the ability to provide this coverage.
This is one of the reasons the cover three defense is so good against the pass-and-run plays. A stronger safety line wide of Sam but on the inside of a cornerback.
In a snap, the stronger safety and Will split wide to help provide cover on the void area left by the cornerbacks.
When teams defend a running play, the strong safety and three linebackers take the primary responsibility of covering holes, making tackles, and funneling ball carriers.
Stage 3: Set up the Secondary
With a strong safety lining up as a linebacker, we now have two cornerbacks and free safety as the secondary.
The free safety lines are in the center just behind Mike and provide coverage deep in the middle. But the safety can shade left or right depending on the direction of the pass.
You’ll also have the two cornerbacks line up at the line of scrimmage. They also have the freedom to take a few steps back to identity, whether it’s a pass or run play.
Football Cover 3 Defense FAQ
What’s the Difference Between Cover 2 and 3?
The difference between a cover 2 defense and a cover-three defense is the number of players in deep coverage. A cover three defense employs three defensive backs, while a cover-2 defense employs two safeties.
Who Invented Cover 3 Defense?
The cover 3 defense was invented by George Halas in the 1950s. George was the coach of the Chicago Bears by then. The defense formation has since been adopted by many teams.
How Do You Beat A Cover 3 Defense
You can beat a cover-three defense by running a spread formation or play action. The offense running a spread formation or play action will trick the cover three defense and create gaps for running backs.
Conclusion
A 3 cover defense is a pretty versatile defense and one every team should have in their playbook. Comprising three defensive backs and four linebackers underneath, the defense is simple and effective. It works well against the run-and-pass plays.
Additionally, the defense is easy to adjust, with players taking specific responsibilities.
By far, this is the most popular zone-based type of defense in football. However, like any other defense in football, there are strengths and weaknesses to the three cover defense. Teams should know how to run a three-cover defense and when to best use it.