MHR University has done some work in the past with covering the 3-4, including the systems being run in the NFL as well as the importance of the NT position. Now let's take a jump from intermediate theory to advanced concepts.
In today's MHR-U we will look at two areas of subject matter. 1) What is the difference between each of the DE and LB positions in terms of responsibilities, and 2) What are the considerations for blocking at the line for a 3-4.
Throughout the following, I'll be discussing the positions in generalities. Bear in mind that systems and schemes may adjust the following information. I'm covering the 3-4 at its most basic level. The tweaks that a coach makes to the 3-4 is what creates the different systems we've discussed in other articles about 3-4 systems and related stories.
Three articles to read to help you with understanding the concepts in this story:
MHR-U story about the 3-4 formation
MHR-U story on gaps and techniques
MHR-U story about the nose tackle
Part One - Position Responsibilities
The RE and the LE -
Is there a difference between DEs in a 3-4 and 4-3? Are there differences between the RE and the LE? The answer to both questions is yes.
In general terms, the defensive line must be more physical in a 3-4 than a 4-3. This is obvious to most folks, as the 3-4 gives up a lineman. What may not be obvious is that the responsibilities of the defensive ends change as well.
In the classic 4-3, the ends either rush the passer or occupy the offensive line to help the LBs make tackles. In the 3-4 we see some subtle, but major changes.
The number one most important trait, bar none, for a DE in a 3-4 is explosivenss. Slowed film study shows time and again that the most critical feature in who wins the battle on the line is who "fires out his stance" first. Even size takes a backseat, and technique becomes harder to execute if the other guy beats you to the punch.
The pass rush is more difficult for the ends in the 3-4 because their alignment is not as wide as they would be in the 4-3. It is impractical for the ends to rush by going around the offensive tackles, and bull rushing becomes a more critical skill set.
Also, the ends pick up a skill set not seen as often in the 4-3; walling off an offensive lineman to allow the LB a lane for the blitz. This is much more common in the 3-4 because there is much more space to operate in (whereas the 4-3 is too cramped in most cases for such a maneuver). It is also more common because many DEs in the 4-3 are lighter pass rushers and less capable of the technique. (The exception is 4-3 DLs featuring run stuffing DEs).
We'll cover more on the blocking considerations in part 2. There we will see that the DEs to a large part occupy the OL, and do it differently than in a 4-3.
But do the right end and the left end differ at all? They do, but much less so than in a 4-3. In the 4-3 (generaly) , the LE is the more physical end because of two reasons. 1) more runs come to his side, and 2) A TE is often on the defense's left side, ergo an extra blocker.
In the 3-4, the classic response by an offense is to feature 2 TEs to block out the OLBs, thus the TE issue is a lessened factor. Also, because space is increased in a 3-4, the DEs are even less likely to tackle a runner and more likely to occupy the offensive line so that a LB makes the tackle.
Keep in mind that 3-4 defensive ends can be one or two gap players just like in a 4-3 (despite the popular misconception that 3-4s feature 2 gappers entirely). However, the DEs must be much more physical than their 4-3 counterparts because they are more outnumbered on the line, and have the added responsibility of walling of the OL (much more than the 4-3). Each should demand double coverage, whether hitting a gap holding up O-linemen.
So how do the ends differ from each other?
(Remember that the positions "right" and "left" are from the perspective of each team. Thus the right end on the defense is on the left side of the offense, etc)
The right tackle on the offense is usually more of a run blocker, while the left tackle is usually more of a pass blocker (protecting the QB's blindside). Therefor, the ROLB is usually more of a blitzer than the LOLB. Because the RE in the 3-4 won't be going around the LT, he needs to occupy that RT for the ROLB to have success. If a TE is on the weak side, the RE will likely be expected to stunt the gap between the LT and the LTE. (The stunt will likely be a "cross-rush", where the LE takes the gap I explained, and the RILB hits the gap between the LT and the LG, further drawing the left side of the offensive line from protecting the QBs left side). This much used piece of larger plays requires the RE to be slightly faster (particularly in lateral movement) than the LE.
The LE is more like a pure DT from the 4-3. He rarely has speed, instead relying on size to take two OLmen out of plays. He is much less likely to stunt. He is no less important though. If he can occupy the RG and RT, the LILB and the LOLB are very likely to tackle a runner quickly. The FB and the OC should be taken out by the NT, and the TE shouldn't be a factor on inside runs, leaving two run stoppers against the RB.
Even in zone blitz systems (where a speedy DE helps in zone coverage), the oft double teamed DE should be enough of a threat that when he unexpectedly drops back into coverage, the LBs are able to hit gaps from unexpected directions (the OL is mentaly preparing to go toe to toe with a DE who suddenly isn't there, while the LB runs by).
Because the job of the DEs in the 3-4 is more often the occupation of OLmen and not the tackles and sacks of the 4-3 DEs, the 3-4 DEs get much less appreciation despie their vital role.
The LOLB and the ROLB -
Wide alignment is the name of the game. The OLBs are more likely to be in place for wide blitzes than their 4-3 counterparts (though the 4-3 OLBs have more help at the line). They are more likely to be in better position for runs to the outside. They are more likely to have passes come their way for INTs (because the midfield features more LBs and thus more zone potential in that area). In short, the OLBs have more chances for "glory" plays, but the tradeoff is that they are sharing the glory plays with three other LBs instead of two.
From a coach's perspective (and a fans), who really cares? Regardless of who gets the credit, the "fun" plays are going to happen more often when the coach has more options. This doesn't make the 3-4 better than the 4-3 at all. Both formations have strengths and weaknesses. But for the sake of watching plays for aesthetic reasons, the 3-4 is the way to go.
As in the 4-3, the ROLB is typically faster, needing to blitz more often on the side less likely to have that second TE. Even when a team has a second TE, he is likely to face the "lesser" TE of the two. (Which is why some teams are blessed to have deep talent at TE, like Denver and Pittsburgh). He might occasionaly blitz inside the line to pull the offense for the real blitz on the left side, but not too often (The Phillips system features this concept more than the others).
The LOLB is radically different, depending on the system. He may be a speedy but physical blend for pairing with the TE on pass coverage, or he may be a physical speciman that hits the gap with the DL to free up the ILBs for stopping the run, or he may be pure speed (zoning the strongside or blitzing wide).
Both OLBs are far more likely to divide their time between zones, blitizes, and man coverages (in that order) than the 4-3 OLBs. 4-3 OLBs are more likely to either zone or man, and blitzing is the secondary function. Thus, 3-4 OLBs are more flexible than the majority of their 4-3 counterparts.
The RILB and the LILB -
The MLB enjoys the protection of four DLmen. LB great Ray Lewis once famoulsy opined that he much prefered the 4-3, because he could get the protection to do his job better. What he left out was that he was doing great things in the 3-4, and the rest of the LBs looked pretty good too (something that Ray my not have wanted to do; share the spotlight).
Because there is an extra LB (some go so far as to say an extra "true athlete", though I disagree) on the field, there is a greater likelyhood for "big plays". INTs, sacks, and fumbles (or a combination of the three) should occur at a higher rate, at least in theory. Meanwhile, the 4-3 should feature more "standard" plays (three and out because the offense simply couldn't move the ball).
Flexibity increases for the LBs too. Any LB can play in a 3-4, and his strengths and weaknesses can be taken into consideration when the coaches draw up the plays. In a 4-3, the roles are more rigid because there are less LBs to scheme with.
This brings me to the ILBs. They can be fast or big or a good mix, much like in the 4-3, but with a twist. Because the DL has one less man (even though 3-4 teams fight to acquire double coverage demanding players), the ILBs tend to have one common trait. Their skill set must include the ability to shed run blockers, or they just won't be an asset.
The most common offensive technique to hurting a 3-4 is the power run up the gut. In a properly schemed and executed power run in the middle, the 3-4's front seven will be outnumbered. The ILBs must be able to shed at least one run blocker in order to make the play. If they can't, they had better hope the SAFs can make the play. Like the 4-3, the ideal is for the SAFs to support the CBs. If the front seven can't handle power rus up the gut, the defense has to choose (by changing the SAF duties) which way they want to lose, ground or air.
On the other hand, the 3-4 pairs nicely with many teams in the NFL that feature fast RBs, sweep plays to the edges, and short and medium passes. If the ILBs are exceptional, the 3-4 can match up even with the occassional power running team.
In the recent past, it was more difficult to prepare for the 3-4 because players don't practice against it too often. As the 3-4 has come back in popularity, thiadvantage has been weakned somewhat.
Are there differences between the RILB and the LILB? Not so much. Both players must be able to shed blockers as a number one trait, and must be able to act as a light DT if called upon to rush the line. Yet they must still be able to stop runners (the number one job), do an effective job blocking passes (almost always in zone), and often joining in a blitz to flush out a QB who isn't known for his mobility.
Next week in Part Two we'll go in depth with some of the considerations and tactics found in developing trench warfare solutions, including sub set plays for the DL, and assistence from the LBs.
As always, your questions are very welcome (no question is too "simple". We're all here to learn, regardless of how much football you know). Questions can relate to this story, or anything else related to the game. If I can't answer your question, we have a lot of members and staff with expertise (draft, sports medical, legal, salry cap, team history, etc).
Also, if you have an idea for a future MHR-U story, please let me know.