Controlling the line of scrimmage has been the foundation for every great Steelers' team. It allows for the linebackers to stay off blocks and makes it easier for gap integrity to be maintained.
That's why the Steelers continue to invest in their defensive line, despite the calls for their secondary to improve.
What was most remarkable about this season's group was not just the players they invested in with high draft picks to become starters, but the depth after injuries forced reserves into key roles.
CAMERON HEYWARD
The Steelers' leader in sacks from 2015 looked to be on the path for another solid season in 2016, but a season ending injury to Cameron Heyward at mid-season forced their rotation of defensive linemen to step up.
Strengths: Heyward brings more than just his physical talents to the game, he also is probably the best on the roster of knowing where to be, what gaps to fight for and how to penetrate on key passing downs.
Take a look back at his sack on Alex Smith in the regular season. The Chiefs were trying to find a way to get going and called for Smith to roll to his left along with the offensive line to open up some passing lanes. Watch how Heyward engages with Zach Fulton (73) and wins the battle the entire way:
Heyward knows his responsibility is B-gap, which is to the left shoulder of Fulton. Heyward uses his inside shoulder and arm to engage Fulton while keeping his legs driving to get through the line and cuts off Smith in his attempt to get outside the pocket.
What might not show up on film is how much of a leader Heyward is.
Weaknesses: There's no real major weakness in Heyward's game. He often can read where the play is going and is a player that's rarely out of position.
Even in his worst moments, Heyward is still one of the more consistent players.
Value: At an age of 27, Heyward is in his prime and should bounce back from his season-ending injury just fine. Having him back in addition with the depth found on the defensive line will be a significant boost to the young defense.
STEPHON TUITT
When the leader went down in Heyward, Stephon Tuitt stepped up in many ways. The third-year player out of Notre Dame wasn't as savvy as Heyward, but his strength and natural football instincts won him many battles at the line of scrimmage.
Strengths: With the Steelers using more sub-packages, Tuitt plays less of the role of a defensive end and more of the role of a defensive tackle. That means that he's responsible for interior gaps and taking on double teams more consistently throughout games.
What doesn't change though is the importance of Tuitt being able to not give up any ground while keeping his head in the play. That's something he's done a lot in his young career, and this year was no exception.
Take a look at this play against the Dolphins in the playoffs. Tuitt engages the right tackle, keeps a wide base and is fully aware of his responsibilities:
The Dolphins try to fake a triple option to fool the Steelers, but Tuitt never buys it. He knows his gap assignment is B-gap, and he can't afford to give it up just because of a stunt. By staying in his lane, he watches the entire play unfold and tackles Jay Ajayi for no gain.
If the Dolphins do run the option, they're running right into Bud Dupree, and it will be the responsibility of the players behind Tuitt to stop it.
Like Heyward, Tuitt is an absolute bruiser. He can win a lot of battles on his pure strength, which says a lot in the NFL, and that's often what allows him to collapse the pocket on opposing quarterbacks.
Watch how he gets this sack against the Browns:
Once he engages with the right tackle, he's able to work the edge and keep his legs driving to get around and get to the quarterback.
Weaknesses: Now the problem with that play was that it wasn't really a technically sound rip move that Tuitt pulls off, and that's where I see his biggest weakness.
Tuitt lacks those natural pass-rush moves that help you get past better offensive linemen. Notice when he gets out of his stance that he first touches the tackle's outside shoulder, then engages with his right arm.
Usually if you're trying to slap a lineman's outside shoulder, that is the setup for either a swim move or a rip move. The swim is when you use your opposite arm to go over the head of the lineman and not try to engage as much, while the rip is more physical as you try to work through an opponent's shoulder to get behind them.
The rip is a classic that's employed by James Harrison regularly, but Tuitt doesn't do some of the little things that make it a great tool to have. First, a rip move starts with a good step from the side of your body which you're going to use to work through your opponent. Your foot should be placed crossing toward the opposite side, then followed by your arm crossing over with it that allows you to get under their shoulder and gain the leverage needed.
Tuitt uses the slap from his left hand and brings the right arm for the rip, but his feet aren't in position and the rip move turns into basically him just running around the tackle instead of through him.
While it worked out here, you need to be more technically sound to beat better offensive linemen in the NFL. Tuitt's lack of technical execution in his pass-rush moves is a major reason why he only had four sacks. He's still very young and can develop those moves, just like Heyward did, so it's something he should be working on come next training camp.
Value: Tuitt's performance against the run and constant awareness of keeping his head up is exactly what the Steelers need at the defensive end/tackle position. Him and Heyward are a force together and can account for as many as four offensive linemen at a time, giving the linebackers more space to work.
He's also only 23 years old, four years younger than Heyward and on a rookie contract. When Ryan Shazier is going to need to be re-signed, Tuitt should be right there with him. He's every bit as important to the building of this young defense as anyone else.
JAVON HARGRAVE
Javon Hargrave was the most intriguing rookie to me coming into the season because it was much more difficult to find a lot of tape on him. What I did see was a very successful player who won many of his battles with expert fundamentals and outworking his opponents rather than overpowering them.
The worry about that was the extremely small sample size I was going off of, and that he wasn't up against the top-tier talent in the NCAA regularly.
Hargrave put those concerns to bed quickly, and proved he belonged in this defense throughout the season.
Strengths: Against the run, Hargrave was often in the middle of the defense attacking his gap assignment and engaging with one shoulder while keeping the other free to be ready to make a tackle.
Notice how he does it here against the Bengals in a one technique, engaging the center and forcing Jeremy Hill to cut back into the heart of the Steelers' defense:
What Hargrave lacks in size and brute strength, he makes up for in sound fundamentals. His hands are extremely quick, which is vital to keeping opposing offensive linemen from gaining any leverage on him, and keeping him free enough to make a play in his space.
Hargrave is also well-schooled and show his ability to work around linemen in small spaces. Watch how he gets this sack on Tom Brady:
Hargrave sets this up with a quick step to the outside, and an even quicker step to cross the face of the guard in front of him. Once he crosses his face, he has a path right to Brady. But even when the guard recovers and manages to get in his way, Hargrave throws him off without ever taking his eyes off Brady.
That leads me to my next point of emphasis on Hargrave, his football awareness. Several times this season, I saw Hargrave sniff out screen passes and figure out just where opponents were going in run plays. He stays home, reads his keys and executes.
Weaknesses: While all of that is great, the biggest knock on Hargrave still how small he is, and how easy it is to move him if you get past his footwork and his hands.
The only times I saw Hargrave blown out of his hole were when opponents got a quicker jump on him, allowing their hands to get in position, and were able to drive him where they wanted. That didn't happen often with the way Hargrave played, but teams noticed it and tried to key in on him when he was playing as one of the interior linemen in the Steelers' nickel package.
Value: The Steelers really nailed their third-round pick last season finding this guy. His early success does not appear to be him just happening upon fortunate moments or people underestimating his strength, but rather his outworking opponents with his repertoire of moves.
He's going to be a lot of fun to watch in the coming years as he refines his moves and style of play.
L.T. WALTON
Hargrave wasn't the only surprise the Steelers had this season, as L.T. Walton became instrumental to their defensive success in the absence of both Heyward and Tuitt at points of the season.
Strengths: Like Tuitt, Walton is a tall and heavy lineman who can beat you on his pure strength. He's relentless when he's attacking his gap and is a handful when teams try to run anywhere near him.
Watch how he sets up this stop by crossing the face of the right tackle, getting past him and taking out the pulling guard on who was coming to lead block for Hill:
This effectively blows up every hope the Bengals had on the play. They were hoping that the crackdown from the tackle would give their guy the best momentum to blow Walton up out of his gap, but Walton capitalizes on the tackle placing his head to the wrong shoulder.
Once Walton gets past him, he uses his right arm to completely reject the pulling guard from ever coming into the play. That allows for Shazier to remain free and keep his gap, which scares Hill into a backpedal that leads to a big loss.
Walton essentially forced the Bengals to double team him in a situation which they could not afford to in this run scheme. He regularly takes on double teams effectively as well, even when that's the actual plan of the offense.
Weaknesses: Walton's biggest liability in his game is his lack of pass-rush moves. While Tuitt needs to refine his to make them work, Walton's even further behind. Watch this play and see how he's basically swallowed up by the right guard, never really even collapsing the pocket on Joe Flacco:
What is remarkable about this play is that it shows how often Walton is ready to hustle to make a play. When he sees what he can do, he often goes and makes it happen. That's a big factor into why the Steelers' defense never folded in the absence of Heyward in the second half of the season.
Value: While Walton won't be an expert interior pass rusher anytime soon, he's still a very valuable depth player that the Steelers will be happy to keep around for cheap. He plays against the run extremely well and is rarely a weak spot in the Steelers' defense that gets exploited.
DANIEL MCCULLERS
The biggest member of the unit is also arguably the one that needs the most work. Daniel McCullers is a player that is huge and can be a powerful force in the middle of the field, but can also be a big liability to the Steelers in the same game.
Strengths: McCullers' biggest strength, is in fact, his strength! He's so big that if he's not blocked correctly, he'll shed right through you and take up a huge amount of space in the middle of the defense that can shut down the run.
Take a look at this goal line stand against the Browns:
See how he just shoves the right guard out of the way? Once he's in the gap, no running back is going to run him over. He does a good job here plugging the hole with Tuitt and letting his body do the work once he gets free.
Weaknesses: The problem with McCullers is that he's the least technically sound of any of the Steelers' defensive linemen. Watching his tape I saw him higher up in his stance more often than any other linemen. While his 6' 7" height certainly plays a factor into that, it also makes him an easy target for the better NFL linemen to get inside on his body, gain leverage, and move him out of the hole.
Take what happened on this Hill touchdown, for instance:
The Bengals do double-team McCullers, but he should never get driven five yards off the ball and into the end zone in this situation. Both linemen on him get their shoulders under him and drive him off the ball, making him essentially the perfect target for a classic sled drill that linemen work on even in their pee-wee days.
When an interior lineman gets blown up that much in the middle of the field, opponents are going to capitalize with big plays. Unfortunately for McCullers, that's what kept him off the field for much of the season until depth became an issue for the Steelers.
Value: Moving forward, McCullers will need to hone his fundamentals a great deal if he expects to become more of the Steelers' scheme.
RICARDO MATHEWS
Ricardo Mathews was a welcomed free agent addition that many might overlook, simply because he was injured late in the season and because he's a backup defensive linemen. But Mathews became a reliable depth player in a position where the Steelers needed one to be much better than that of Cam Thomas, who had held Mathews' position on the depth chart for the previous two seasons.
Strengths: Mathews almost always is the lowest man in his battles at the line of scrimmage. The saying for linemen is that the lowest man wins, and that's what made Mathews reliable as the Steelers called upon him more.
Watch how Mathews engages Darren Waller (84) to the left of your screen. Mathews uses him to work his gap until he finds where the play is going and finishes with a good tackle on Terrance West:
Mathews is quick off the ball and more technically sound than your average backup defensive lineman. When he was with the Chargers I saw a guy that could be a solid spell at defensive end to keep the Steelers' best players fresh, and that's what he brought to the table.
Weaknesses: The complaints on Mathews aren't major enough to make a huge stink about. He's a depth player that isn't expected to be a huge playmaker. He doesn't have extreme physical prowess to dominate opponents and isn't a master technician, but he does a lot of the little things right and has a solid football IQ. That's what the Steelers want out of a depth free agent pickup.
Value: Mathews is a free agent this going into 2017. While his play was satisfactory, I see the Steelers moving on from him unless he's willing to take an extremely cheap contract. The Steelers have Heyward and three dependable guys behind him that are all under 25 years of age.
It make sense to think that they'll save a little bit of cap space to put it elsewhere, and maybe pickup a replacement for Mathews with a later round draft pick.
JOHN MAXEY
Another reason why I think Mathews will be gone is because the Steelers liked what they saw of John Maxey who came off the practice squad late in the season. He's already under contract for very cheap and looked like a player who could execute within the Steelers' scheme just fine.
Strengths: Maxey had a very small sample size to pick through, but when he was on the field it seemed like he could be a solid depth player. He's quick off the ball and looks like a guy that has a plan each time he engages offensive linemen, going for different moves in his toolbox to get the job done.
Watch the play below to get a sense of what Maxey tries to do to opponents. He's not the biggest or the strongest, but he, like Hargrave, looks to out execute you in small spaces:
Here he explodes off the ball and executes a solid swim move to get around the center and make the play in the backfield. What's even more remarkable about this play is how much space he had to account for. Look at how much space is between him and McCullers, and how Timmons is blocked at the start of the play.
If Maxey doesn't swim his man and occupy the middle of the line, that's a clear path for the Browns to run through. While this is the Browns, it shows that Maxey may have the potential to be part of the rotation on the defensive line.
Weaknesses: Maxey's biggest weakness might be his average build and athleticism, but there's not a great deal of information to work from to determine that just yet. He had a solid performance at the end of the season, but ultimately is still a question mark going into next season.
Value: Maxey is going to make less than half a million next season before his contract runs out. That gives the Steelers time to see if he's worth a small contract to be in the depth of their defensive line or if he'll just be another player they shuffle in and out to maintain their salary cap situation so they can sign their stars.
OVERVIEW
The Steelers are extremely young at defensive line with three obvious starters who look to be very good going into next season. Walton proves to be a solid rotational backup, which means they will have a solid two-set rotation to switch in and out with Heyward and Tuitt as the first and Hargrave and Walton as the second for their nickel formations.
While they will need to figure out what to do with Mathews and if they're comfortable with Maxey and McCullers as their last set, it seems like that's not a big concern to worry about.
Hargrave is a player who is listed at defensive tackle but can rotate to defensive end, if necessary, as he did in Heyward's absence. The flexibility of both him and Walton allow for the Steelers to have some room for comfort in case of injury, but the Steelers might want to take a look at either re-signing Mathews or adding a person in his stead considering how their depth got tested this year due to injuries.
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