While the draft nears, and Detroit interviews players, the question is: what is missing from Detroit's 4-3 defense to be successful?
For those who don't know how to run a 4-3, I'll go through the basic steps to operating a successful 4-3, with certain player personnel groups.
A 4-3 defense consists four men positioned on the line of scrimmage, while for a 3-4 three men are on the line of scrimmage.
Before confusing you, I won't go into the details of defensive lineman in other forms of the 4-3 or 3-4; we'll leave it at that.
One thing to keep straight, though, is that some defense's play what is called a 3-4 Eagle, which is commonly mistaken for a 4-3, and vice versa, because one of the defensive lineman is lined up against two offensive lineman.
Now as for the defensive line positions, there is a nose tackle, who stuffs the gap between the center and guard, a three-technique defensive tackle, who stuffs the guard and tackle. He can also fill the role of a one-gap or two-gap, and pretty much pushes the pocket back and fills the space between the offensive players.
Also, there is the commonly referred to position of defensive end, which stuffs the gap between the tackle and tight end; it's his job to push the play back inside whenever it is possible to do so. Then there is the rush end backer, who attacks the weak tackle to either rush the quarterback or contain the run so that it stays between the tackles.
Now we get to the "3" in the 4-3, the linebackers.
There are common names for linebackers, including outside and middle linebacker, but in a 4-3 the positions have different names.
There is the strong side outside linebacker, who is responsible for the tight end on the defense and to make sure nothing gets outside the DE (this responsibility can also be switched to the weak side outside linebacker at times). The weak side aligns to a five-gap position, and is there to help contain and shuffle essentially parallel to the line of scrimmage until a blocker comes near. Also, the weak side linebacker is the quickest of the other two positions. He is the likeliest player to be called on to blitz the quarterback.
Then the last linebacker in the inside is the mike linebacker, who protects against the run, covering a strong side gap as well as the weak side, while usually playing five yards off the line of scrimmage. He is most valuable in recognizing the offensive formation, and makes the call for the lineman upfront. He also attacks the blocker head-on, essentially as a train pushing through them.
Finally comes the secondary: strong safety, free safety and corner. The strong safety is mostly meant for run support, especially in a zone; in a cover-2, he is responsible for the deep patterns, playing alongside the free safety. The free safety MUST have coverage skills, and covers the deep ball unless playing close, where he moves up in short yardage or in a blitz.
Lastly, there is the corner, who covers the split end on the weak side and the flanker on the strong side. He usually plays man-to-man, until they leave the box and are assisted in the safeties' zone.
Onto Detroit's 4-3: Detroit's current season-opening roster would look like this:
NT: Sammie Hill or Corey Williams
Three-DT: Ndamukong Suh (let's face it, Detroit will be idiotic to pass him up if they stick at second overall)
DE: Kyle Vanden Bosch and Cliff Avril
REB: Jason Hunter
SSLB: Julian Peterson
ILB: DeAndre Levy
WSLB: Ernie Sims
SS: Daniel Bullocks
FS: Louis Delmas
CB1: Chris Houston
CB2: Jonathon Wade
While that may not seem great, Detroit has put the right pieces into place.
Sammie Hill or Corey Williams will likely play nose tackle. Since the nose requires a player who is able to play between the center and guard, Hill could penetrate with his size, as would Williams.
The three would be played by Suh, since he pretty much can push back the line by himself, and ease up the workload for the other players while creating opportunities.
Then there is the breakout player, Jason Hunter, to play rush end. With his startling 4.48 speed he can quickly get to the weak side, is able to minimize the pocket for opposing quarterbacks, and can be there to tackle the runner behind the line of scrimmage.
Getting to the defensive end on the team, a position that performed under-par last year, the Lions have added new pieces to the line, with Vanden Bosch and situational-nose Williams also able to play end.
Since they both we're acquired this offseason, we do not know how they'll mesh with the team, but if the way they played on there former 4-3 teams says anything, they'll be an improvement over Detroit's guys from last year.
Williams fell off the radar when he played in a 3-4 at Cleveland, since his natural ability is best catered toward a 4-3. The Packers ran this in his earlier years, when he was able to sack the quarterback seven times on average when starting all 16 games; he disappeared in Cleveland, making an average 2.5 sacks.
So, we jump into the linebackers, who have not disappointed as much. With another breakout player in DeAndre Levy, along with seasoned vets Ernie Sims and Julian Peterson, this unit looks to remain solid.
Peterson is likely to play the strong side, as his size and ability are able to help the end in protecting the line and containing the tight end or runner. Then, Sims will play the weak side; due to his speed he can quickly move to the line of scrimmage to be able to attack the runner. Lastly, Levy can play inside, to essentially be there if anything fails and use his knowledge to help fix the broken play.
The secondary is basically all new, and with more guys likely to be added during the draft, a pure assessment on them would just be far fetched right now. But with fourth year player Chris Houston starting at corner and potentially having the breakout year that he never achieved in Atlanta, he could help begin the turnaround in Detroit. Wade is there to play alongside Houston and be the slot corner, while leaving who they draft to protect the second receiver.
Which finally gets to the question: what's missing?
Detroit needs to address the secondary, acquiring depth in the draft.
The secondary, again, is all new pieces, and with half of the current players meant to be no more then special teams guys, if a starter were to go down, then the Lions would be in a dangerous position. The talent is not great enough amongst the current roster to provide for another starter, so an injury would really weaken the defense. While Detroit isn't done with signings and still has the draft, those positions are likely to be paid close attention to in the upcoming weeks.
All in all, Detroit has a formidable 4-3 defense come the season opener. After addressing the depth on the line and in the secondary, Detroit could make the jump into the top half of defenses around the league.