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Offseason Knowledge Base: Alabama’s defensive secondary

The verbiage behind those guys defending the passes

NCAA Football: CFP National Championship-Clemson vs Alabama Mark J. Rebilas-USA TODAY Sports

In our first two installments, Erik has already lectured all of you on the intricacies of the front-seven players on a defense. But no defense is complete without the little, speedy guys running around in the back-end of the field trying to keep passes from being completed and making touchdown-saving tackles.

With the front 7, you see major philosophical differences between teams that run a 4-3, 3-4, 46 Bear, 3-3-5, or a 4-2-5. And while some of those differences carry over into the secondary (such as the role of the 3rd safety in a 3-3-5), you will generally see more similarities between teams despite formations. The changing roles depend more on different play calls than they do formations, and often the defensive backs’ roles and formation are more or less dictated by the opposing receivers anyway.

So, we’ll start by going through each position and what a team looks for at each place, then move on to how they end up working together on a given play. I’ll start simple, and get deeper as I get more and more wordy.

First, you have the cornerbacks. In a base defense, there are two of them, usually one on each side of the field, lined up directly against the receiver. More often than not, the cornerbacks are the fastest and most athletic players on a football team.

Why? Because, most of the time, their job is to be able to run just as fast as a wide receiver, despite not knowing where that receiver is going to go.

In 2016, the two men manning that position were Marlon Humphrey and Anthony Averett, both of whom are known for being track stars as well as football players.

Humphrey is the cornerback nearest the camera, while Averett is one on the opposite side who starts on the 15 yard line and then shuffles backwards as he follows WR #15.

Now, on any given play, a corner will be in one of two types of coverage: man-to-man or zone. In man, he lines up with the receiver in front of him, and follows that receiver, no matter where he goes on the field. In zone, a cornerback is assigned a certain area on the field, and will cover any receiver who goes into his area.

An example of man coverage:

Again, check out Marlon Humphrey on the far side of the screen. He lines up with the receiver there, and then sticks in his hip pocket, even as the receiver runs forward and then stops and curls back around.

Again using Marlon Humphrey against Tennessee (because the video I was using was focused on him), we see an example of zone coverage:

Here, Humphrey is lined up to where, if he were in man-to-man, he would cover WR #3, the man closest to the screen. But when #3 runs toward the center of the field and and the inside receiver goes out, Humphrey doesn’t follow to the inside, but instead stays in his zone and makes the tackle on a different receiver.

The other members of a defensive backfield, the safeties have different responsibilities than the corners.

There are also two safeties in a normal defense, usually called a “free safety” and a “strong safety.” Depending on the coach, preferences, and players available, some teams prefer the free safety to be faster and better at pass coverage while the strong safety is bigger and a better tackler. Others, such as Alabama, use the two interchangeably, more like a “right safety” and a “left safety”

In 2016, Ronnie Harrison and Eddie Jackson were the two safeties (and Minkah Fitzpatrick took over after Jackson got hurt).

The safeties are generally the furthest players from the line of scrimmage and are generally considered the last line of defense on preventing big plays. Like cornerbacks, they will either be in man or zone coverage, though usually with a little bit of a different focus. When in man coverage, a safety will usually be matched up with a slot receiver, tight end, or running back, rather than the offense’s best receiver. In zone, they are often dropping 20 yards or more backwards from the line of scrimmage to prevent deep passes.

So, you got that?

If you’ve spent much time listening to announcers in any football game, most of this is probably old knowledge. But hey, I like to cover the jargon before moving on so we don’t lose anyone before we get started.

Next, we discuss some basic coverage concepts and how these fine men all work at the same time. The verbiage is easy enough. Most any play will be a variation of one of five types: cover 0, cover 1, cover 2, cover 3, and cover 4.

I’ll explain it TL;DR fashion, but if you want more detail, pictures, and the history behind some of these coverages, check out this link. It’s definitely worth your time.

Cover 0 involves everyone playing man coverage, except for those blitzing or rushing the quarterback.

Cover 1 has one member of the secondary (usually the free safety) playing a deep zone in the center of the field. Everyone else is in a combination of either man or short zones.

Cover 2 has both the free and strong safety playing a deep zone, one on each side of the field. Everyone else is either in man or a short zone.

Cover 3 has three players playing deep zones: left, middle, and right. Most often, that will be the two cornerbacks on the outside and the free safety in the middle. Though rotating versions can have one corner and two safeties playing a deep zone.

Cover 4 is the infamous “prevent defense”, and by now, I bet you can guess what it means. All four members of the secondary play deep zones.

That’s all well and good, right?

But everything mentioned above was assuming there are only four members of the secondary in a base defense. Which, in this era of football, is mostly a relic (really only making it’s appearance when Alabama plays LSU or Arkansas).

What happens when an opposing offense goes to three receivers, rather than two? Or even four?

Suddenly, you will end up having a hulking linebacker trying to cover a slippery little receiver in open space, and the offense starts scoring. A lot.

This is when the defense will substitute a 5th member of the secondary in lieu of a linebacker or defensive lineman. The new formation with 5 in the secondary is known as a “nickel” defense, and, in a Nick Saban defense, the new position is called the “Star.”

In all reality, it’s just a defensive back who is now playing the Sam linebacker position, and Saban wanted to stick with an “S” as the first letter. But, since there’s now a 3rd receiver, the extra speed and coverage ability is important.

According to Saban:

“You can be a really good Star and not have the long speed to be a good corner,” he said. “Long speed being that if a guy runs a takeoff on you, you have to run and not get out run when the ball is in the air.

“If you have really good quickness and cover ability, the slot guy (receiver) has a hard time beating you in that position, because he's closer to the safeties, he's closer to the middle of the field. So a good tackler, a good blitzer, a good cover guy on a slot player, which is different than a good cover guy on an outside player.”

So quickness (because the slot receiver can go either left or right, as he isn’t as bound by the sideline as an outside receiver) and tackling ability (because he must take on the role of a linebacker if the opposing offense calls a run play) are the most important qualities of a Star. Last season, that was Minkah Fitzpatrick (until he moved to safety, then Tony Brown took over)

If the offense brings in a fourth receiver, then the defense will usually substitute in a 6th defensive back, and this is known as a dime formation, while the sixth man is called, by Saban, the “Money” position. He’ll take the place of the Will linebacker, and as such, has run defense responsibilities.

Again, the qualities desired according to Saban:

“It helps that the guy's a little bit bigger and physical, because sometimes he has to cover a tight end, which is a bigger guy,” Saban said. “But he also, unless you change personnel, has to be good enough to do the same things that the Star does.”

While the others usually stayed the same, the player in this position often depended on situation. In 2016, Hootie Jones was there most often, but Shyheim Carter and Deointe Thompson played too.

It’s not rocket science, but if you haven’t been around it, the subject requires some getting used to the jargon.

There are plenty more resources out there if you want to go more in-depth (a particularly interesting subject is that of a cornerback pressing the receiver at the line of scrimmage), but there’s only so much I can say here without getting unbearably wordy.

Don’t you just love to learn?