What is a sack?
We all know, basically, what a sack is—at least those of us who have been watching football since former defensive lineman Deacon Jones first coined the term. Jones, who passed away in 2013 and was inducted to the Hall of Fame in 1980, was one of the truly great sack artists in NFL history. It's incredible to think that the stat has only been officially recorded since 1982.
These days, there's so much more that goes into a sack. Coaches scheme and plan for weeks on end to sack quarterbacks who are throwing more while getting hit less. Rules in the NFL have skewed toward protecting passers and allowing high-scoring offenses to reign.
Yet, for all of the importance we put on the statistic itself and the big hit that often goes along with it, what goes into the preparation for that moment? A sack isn't just one athlete beating another off the line and hitting the quarterback. No, there's top-notch execution and artistry that go along with each and every blitz, pressure and sack at the NFL level.
The Psychology and Physics of the Sack
"Your mindset is that you're a hunter. You're a big-game hunter. Who can set the best trap to catch the prey? That prey is the quarterback." – Hall of Fame defensive end Chris Doleman
Chris Doleman doesn't think a whole lot about pass-rushers today.
When he describes how he collected his 150.5 sacks (fourth all-time in NFL history), the former Minnesota Vikings defensive end draws a pretty distinct line of demarcation between what he did and what pass-rushers today do on the field.
We'll get to his thoughts on technique later, but when Doleman starts talking pass-rushing, it becomes an almost religious experience. He's the high priest of quarterback punishment, and he's licking his chops looking for any potential sacrifice:
Knocking him down on the ground...that was the body language we used. You can't hunt these guys when you're constantly talking trash. Reggie [White], Bruce [Smith], even Kevin Greene...these were guys who got after you. It was relentless. [The rush] was coming every single snap, and it was coming hard and it was coming fast.
Hall of Fame linebacker Sam Huff agrees with that statement. Huff was literally the catalyst to the formation of the 4-3 defense we see on fields today. He was an athletic lineman who head coach Tom Landry decided to stand up as a middle linebacker. Quarterbacks have rued that day ever since.
Huff talked about his mentality in his book, Controlled Violence:
My impact on opponents was immediate. I always made sure that they felt the hit and never let go of my killer instinct. I used to put my head down and stick it to my opponent, telling him that I was going to knock him into the next row of seats. I always had a comment for the other team after every play. "Let's see what you got!" That's how I played the game—all-out, all the time.
Not every great pass-rusher talks like Huff, though. Doleman talked about letting his play do the talking, and former Dallas Cowboys and San Francisco 49ers great Charles Haley echoed those sentiments.
"I tried to get a sack and walked real quietly back to the huddle," Haley told me. "I don't have time for trash talking. They knew who did it."
That's the "pressure" coaches and pundits are referring to when they talk about pass-rushers creating pressure. Sadly, in today's vernacular, it's almost taken on a jargon-level understanding like an assist in basketball—just another stat that's collected in a vacuum under specific circumstances.
In reality, it's so much more than that. It's a cumulative process that builds and eventually can reach a boiling point.
Quarterbacks who don't mitigate that pressure well don't last very long in the NFL. Pass-rushers who thrive on creating that pressure are paid big bucks for doing so.
The pressure, as Doleman said, isn't about a dance or a piece of trash talk. No, it's pain and the fear of more pain. It's a quarterback's muscle memory screaming out that he's about to be hit again. It's every synapse of "fight or flight" instinct firing at once and telling said quarterback to get the heck out of dodge.
Former journeyman quarterback Sage Rosenfels played 12 years in the NFL for a variety of teams. He was hit his fair share of times by big pass-rushers and talked about feeling them bearing down on him:
You gotta have trust and faith in your guys to block them the next time, but once you start to get hit, you consciously and subconsciously start to feel that pressure. Actually, you know, pressure starts to happen throughout the week, especially if you're facing a team that has a great blitzing scheme or a great pass-rusher...guys spend a few days away looking at the tape, and then they get spooked just by seeing a normal zone blitz because they've psyched themselves out with the video.
Far and away, this is the biggest hurdle for young quarterbacks coming into the league. Look at passers like Jacksonville Jaguars QB Blaine Gabbert or the Minnesota Vikings' Christian Ponder. Both are phenomenal athletes with plus arms, but neither is able to do much of anything against a strong pass rush.
Then again, it's easy for you or I to speak ill of a passer who wilts under pressure, having never truly felt that pressure ourselves. Maybe a few among us played quarterback at a high level in high school or the college ranks, but very few people on the planet know what it's like as a QB on an NFL field.
It's important to recognize that, because (too often) people extrapolate what they know into a situation on the NFL field that is totally different. Case in point: Being hit by an NFL lineman, linebacker or safety feels nothing like what any of us have ever felt in our entire lives.
Dr. Timothy Gay, Ph.D., teaches atomic, molecular, optical and nuclear physics at the University of Nebraska-Lincoln. He likely doesn't know what it feels like to be hit by a gentleman with the size and speed of former NFL lineman Warren Sapp, but he can tell us exactly what's happening when such a collision occurs.
In his book, The Physics of Football, Dr. Gay looks at football from a scientific angle to create all kinds of new insights to how the game is played, coached and viewed, but it was his description of the "Conservation of Momentum" as it relates to football collisions that piqued my interest.
Logically, if Object A is moving at a certain speed and hits Object B standing still, we'd expect that Object B would be acted upon to fall backward at a rate slightly slower than Object A was moving at the time of the collision.
That actually isn't the case thanks to the principle of the "Conservation of Momentum," which is the same force that makes those little five-ball office gadgets click back and forth until someone rightfully throws it at the wall.
Let Dr. Gay explain it better than I can, using Sapp and former NFL QB Doug Flutie as an example:
The initial momentum of the two players is due entirely to Sapp and equals his mass times his velocity: 7,440lbm*ft/s (the asterisk means "times"). Remember that total momentum is the same before and after the collision, so the momentum of Sapp and that of Flutie combined after the hit must also be 7,440lbm*ft/s. Knowing Sapp's final velocity, we can calculate Flutie's final speed: 31 feet per second. The small guy really does go flying!
That's the type of collision that has been compared to a freight train in the past—and for very good reason.
Gay also quotes former NFL head coach Sam Wyche as saying: "This is a game of inches and seconds." When one considers the vast speed at which the game is played in such a small area, it's easy to believe that the margin between greatness and being cut is a lot slimmer than any of us can imagine.
Doleman thinks a lot about that slim margin for error. For him, rushing the passer really was a much more complicated and artful skill than he sees from many top NFL pass-rushers today. He thought of everything—down and distance; tendencies of the QB or offensive lineman; is it play action?; is it a five- or seven-step drop?—anything to give him the edge.
"You gotta make the adjustments that'll give you that 100th of a second to get there," he said.
"No one knows how to blitz when they enter the league, I didn't. I went straight up and down against [Houston Texans tackle] Ephraim Salaam. I saw the top of the dome, then he slammed me." – Former NFL safety Matt Bowen
Every former player I talked to walked me back to a few days before picking up the first sack in a big game.
"It starts during the week from film study," Haley said. "I'm not thinking about the quarterback; I'm thinking about the offensive tackle and his tendencies—where he puts his weight and which way he kicks."
Talk of film study is often relegated to quarterbacks and coordinators, and many fans probably can't quantify the many hours that linemen (yes, linemen) put into honing their craft in the film room. Knowing the offensive scheme of one's opponents inside and out can give you that 100th-of-a-second edge mentioned earlier.
On the practice field, the preparation is with much of the same tenacity. Mel Tucker is the defensive coordinator for the Chicago Bears. He describes the focus this way:
It all comes down to execution. So, getting them ready to apply pressure in terms of a scheme call is very similar to getting them to prepare a base call. There are different kinds of pressure—first and second down, passing situations and some that are good for both. Typically, the pressures that you use in those situations, you run those pressures in practice against the type of plays you anticipate seeing in the game.
Not every circumstance can be prepared for, but a good part of the practice week for the defense is installing wrinkles to the base defense and the pressure schemes all tailored for the particular week's opponent.
Tucker describes advance scouting the protection schemes of the opponent based on formational calls and down and distance, as well as looking at individual matchups: "When you add additional people to rush, that creates more one-on-one matchups. You have to decide if you can win those one-on-ones."
Finally, Tucker also spoke about the psychology of the pressure itself: "If you pressure a quarterback, is the pressure going to be effective? Is it going to affect that quarterback and that offense in a negative way?"
Once on the field, however, it's all about speed. As Haley describes:
The first thing I'm going to do is make him respect my speed. I'm going to get off as fast as I can, then I'm going to get as low as I can. Whether I get to the quarterback or not doesn't matter; I just want to make sure he respects my speed. That sets up every move I want to use later—then I set up to go inside, then I set up to go over the top. I'm in the offensive linemen's heads.
Doleman took his stance and looked directly at the ball. "As soon as that ball moved, we exploded." Haley said he tended to lean back in order to see the ball, tackle and quarterback all at the same time. "If any one of those things moved, I'm gone."
After the snap, Doleman (like Haley) had a variety of pass-rushing moves to work with:
That's the difference when you watched players in my era to players today. [Players today] just bull rush over and over. They should have more sacks now than what we had, because they have more opportunity. What is lacking today is the ability to get to the quarterback. These guys today are not pass-rushers.
This isn't just Doleman yelling at pass-rushers today to get off of his lawn. As said before, this guy was an artist at getting after the quarterback. He broke down one of the league's premier pass-rushers today—Houston Texans defensive end J.J. Watt—and came away impressed but wanting more:
I like J.J., but there's some things out there I don't like. I'd rather see him putting quarterbacks on the ground than batting down passes. You have to be able to get up the field, get in that guy's face and knock them down. If you're batting down passes, that means you're in the passing lane. That's not where you're supposed to be.
Certainly, Watt creates a lot of confusion and consternation with his pass-swatting abilities, but does anyone think a quarterback is more worried about a deflected pass than a man of Watt's size and athleticism hitting him in the face? I think not.
As for actually hitting the QB, Haley described it like this: "As soon as I get a half a step in front of the tackle, I tried to bounce up so I didn't reach [for] an arm tackle. I always wanted to get my whole body on him and bring him down as hard as I can."
Fellow Bleacher Report columnist and longtime NFL safety Matt Bowen has seen quite a bit on an NFL field. He wishes more young players used their hands: "I've always said that your hands are your weapons. If you're not going to use them while you're blitzing, just sit down on the field Indian-style."
Hands, when rushing the passer, are of utmost importance. Any lineman in the NFL—from the best to the butt-fumbly worst—wins battles once their hands are on you. It's a fact of NFL life. It's why defensive linemen and linebackers lean around the edge. It's why defensive linemen are taught to swat hands away and why offensive linemen are taught to have a good initial punch.
If you're not ready to do more than just bull rush every single snap, you'd better be the best athlete on the field; otherwise, (like Bowen) you'll end up on the turf. Bowen also pointed out that sacks aren't the be-all, end-all: "Too often guys are going for the big hit...go for the football. Turnovers are more important than sacks."
For quarterbacks, this is a dance that starts in the film room as well. I've always maintained that a good quarterback can do far more to take care of the pass rush than any lineman. It's one of the reasons that the best quarterbacks in the league don't often have top-tier left tackles blocking for them but still manage to stay upright.
Bowen mentioned Peyton Manning as well, as he talked about setting up for a blitz: "You take a step toward the line of scrimmage against Peyton Manning, and he's going to change the call."
As to what the quarterback is thinking about and looking at, Rosenfels explained:
Once the ball hits your hand, the first you're looking at is: Am I being protected? Sometimes, a lineman will quickly beat his man, but you're not really going to see it. Think of it like this: On a busy interstate, you're not going to look at the cars, but you feel them with your peripheral vision.
Having been hit by many of them, Rosenfels was kinder to this generation of pass-rushers, saying that San Diego Chargers linebacker Dwight Freeney and Minnesota Vikings defensive end Jared Allen were the two best pass-rushers he'd played against.
Yet, he also made sure to point out that both spent the bulk of their careers in pass-rusher-friendly schemes—most notably, the Tampa 2 scheme, which emphasizes their role in the rush. These days, it seems like creating that pressure has as much to do with the coach as it does with players on the field.
"At its essence, a pure blitz is about simple math—the defense is sending one more player than the protection is able to block. The Fire Zone takes it one step further. It convinces a lineman that he's blocking the right man and then sets another man free." – Pat Kirwan in Take Your Eye Off the Ball
When it comes to defensive scheming, no one has contributed more to the NFL's idea of a blitz than Pittsburgh Steelers defensive coordinator Dick LeBeau. Now 75, LeBeau has quite literally seen everything the NFL has to offer in terms of defense, and he's thrown it at most quarterbacks who've crossed paths with him.
He was the first guy Rosenfels had come to mind when it came to confusing defensive schemes, and New York Jets head coach Rex Ryan was a close second. Both coaches, he said, emphasize interchangeable parts and create a sense of the unknown for opposing passers.
Bowen played for current Tennessee Titans defensive consultant Gregg Williams in Washington, and he calls him one of the smartest defensive coaches in the league. He noted how Williams' schemes put a lot of pressure on defensive backs, but when they get it right, good things can happen.
His favorite blitz call was Ruby Scorpion 77 Dime:
This is a dime formation with three down linemen, two linebackers and six defensive backs. In a look like this, a quarterback has to suspect someone is coming. The trick is to make sure he doesn't know from where and who it will be.
Here, in Bowen's favorite play, the strong safety (who else?) blitzes off the edge, and there's Cover 7 behind the blitz. Cover 7, Bowen explains, is a hybrid coverage that allows a team to do a lot depending on what kind of personnel they're facing.
In reality, even though this is a confusing play with multiple coverage possibilities, it's a very conservative defense. It doesn't look that way, and it certainly won't feel that way to the quarterback—especially with a hard hitter like Bowen slamming into his chest.
Another blitz Bowen pointed out was the Gut Fire Zone:
This is a zone blitz, which means a defensive lineman (here, the end) is dropping back into coverage to make up for the blitzer. "Gut" indicates that the blitzer (here, the free safety) is blitzing up the middle.
Bowen said that this was a great blitz for slower quarterbacks like former New England Patriots QB Drew Bledsoe. Since one can guess that he isn't rolling out, this blitz means the quarterback is stepping up in the pocket directly into pressure.
Anytime the words "zone" and "blitz" are put together, you can thank LeBeau, who helped create and popularize the idea of a blitz that still maintains sound coverage behind it. As Haley explained to me: "[Teams] didn't blitz much back in my day, unless it was a backs-against-the-wall situation."
LeBeau and Williams actually crossed paths for a season in Buffalo when LeBeau was the assistant head coach to Williams in 2003. By then, however, LeBeau's zone-blitz looks had somewhat taken over the league. Chris Brown explained the progression in his book, Smart Football:
So LeBeau began experimenting with schemes that showed blitz looks—and did in fact rush defenders from unexpected places—but nevertheless dropped a minimum of six defenders into zone coverage. To LeBeau, this was the perfect remedy: depending on the coverage you put behind the blitz, you actually were playing a very conservative defense, but the offense thought you were being aggressive, and, depending on how intelligently you deployed your five rushers, you were being aggressive, albeit in a very controlled sense. Controlled chaos, indeed.
That's the rub with the zone blitz. Blitzes were, at one time, a "backs-against-the-wall" idea, as Haley pointed out. Now, teams blitz and send pressure from all angles and still maintain sound coverage. It changes what teams are looking for out of many positions as well.
In terms of designing a blitz, Tucker described the risk/reward this way:
You want to be sound in whatever coverage you decide to play behind your pressures and make sure your players understand the strengths and weaknesses of the coverage. You can't just assume that every time you call a blitz, you're going to get someone free and unblocked.
If you ask Doleman and Haley, both would point out that the advent of blitzing and the emphasis on smaller, faster linemen has hurt the artistry of pass-rushing. Doleman, specifically, pointed to "small guys who played strong safety in college" being turned into linebackers as part of the problem (as he sees it) in the NFL today.
Tucker noted that today's game has a clear difference between blitzers and pass-rushers, pointing to Chicago Bears linebacker Lance Briggs as a good blitzer but crediting their defensive end, Julius Peppers, as a fantastic pass-rusher.
For quarterbacks, the myriad ways that defensive coordinators can send a blitz package has turned film study into a full-time job—and sometimes even that isn't enough. Tom Brady, according to a recent profile in Men's Health, watches 17 hours of film a week! This is a guy who has already seen a lot in his NFL career, and teams are still able to confuse him at times.
"It really depends on the offense that you're in," Rosenfels told me. "Some offenses deal with pressure by not blocking the pressure—making the defense cover all five eligible receivers. The QB needs to know where the issues are." This is indicative of what lots of veteran quarterbacks like Brady and Manning do. Sure, they can change the play, but if they know an opponent is blitzing, they'll look to capitalize.
There are some philosophical philosophies out there that say: Bring the pressure; you're going to have to cover all of our guys. Or, you can always call a protection that brings backs or tight ends in to block. The other aspect is to have protections on to send the tight ends and running backs out, but have the quarterback manipulate the line.
According to the longtime NFL QB, both philosophies work; it just depends on how comfortable the quarterback is with executing his assignments. Comfort, of course, is the operative word here as defenses look more and more to keep those passers out of their comfort zone.
A lot goes into a "sack." It isn't just a throwaway stat, and it's more than just the moment of impact. True sack artists may be few and far between in today's NFL, but there is still plenty of execution and artistry on the defensive side of the ball that deserves more of our attention.
Michael Schottey is the NFL National Lead Writer for Bleacher Report and a member of the Pro Football Writers of America. Find more of his stuff at The Go Route. Unless otherwise noted, all quotes were obtained firsthand by the columnist.