To 4-3 or 3-4. That is the Question (DL)

One of the big question heading into spring practice is will the Wolverines switch from utilizing primarily a 3-4 scheme to employing a base 4-3. Coach Lloyd Carr will be fielding questions on that and more today. In part one of our review of each alignment, we tackle the fundamental differences in responsibility o the defensive linemen in each set. <p><em>Look out for part 2 tomorrow, where we analyze the linebacker responsibilities.</em></p>

The 3-4 defense was once very prevalent amongst the college and professional ranks, but it has become somewhat of a relic in modern day football. Very few teams on any level run it anymore…making those that do somewhat of a novelty act. The unfamiliarity with the scheme makes it very difficult for today’s offenses to prepare for. A few NFL coaches, namely Bill Cowher, Wade Phillips, and Dom Capers, continued to utilize the 3-4 for more than a decade now and have experienced a great deal of success. That has caused other coordinators to re-visit the scheme in what has become a mini trend. Renowned defensive coordinator Don Lindsey has both seen and used just about every defense in the book. He helped USC to three national championships, six Rose Bowl appearances, and seven, Pac Ten titles and also fielded outstanding defenses at Alabama, Arkansas, and Hawaii. He indicated to in an interview early last year that just because the 3-4 is in vogue again doesn’t mean it’s a superior defense to the 3-4. “There is not a single alignment that is superior to another or I assure you EVERYONE would run it,” Lindsey said. “Players win games, not alignments. The term ‘ideal personnel’ is the key. Both the 3-4 and 4-3 are proven over many, many years of design and execution.”

The Michigan Wolverines utilized a multiple front 3-4 scheme last year and their defense was stellar for the first eight games. Down the stretch, though, the effectiveness waned as middle guard Gabe Watson wore down and the lack of backfield pressure and outside contain left them vulnerable to mobile quarterbacks. The talk now is the Maize and Blue will go back to using more of a base 4-3, (something that will surely be addressed by Coach Lloyd Carr today. Until then, here is a crash course in the differences in the two alignments…starting with the defensive linemen.

The first number in the alignment name refers to the number of linemen, while the second refers to the number of linebackers. For instance, in 3-4, the three refers to three down linemen and the four refers to four linebackers. One obvious trait of the 3-4 is the increased speed on defense. A linebacker replaces one of the defensive linemen in 4-3 scheme. Three of the offensive linemen (the center and two tackles) are covered by defensive linemen, while the guards are left uncovered. One of the most valuable advantages to the 3-4 defenses is the relative anonymity of the 4th rusher. It could be any one of the linebackers or even a defensive back that completes the traditional quartet of pass rushers. This can cause confusion amongst the offensive linemen and forces them to block in space. On the other hand, one of the weaknesses is lack of brawn on the perimeter, as one of the defensive ends is replaced by a backer. That can sometimes result in defenses getting overpowered at the point of attack along the edge. Before detailing the assignments of the defenders, we must first refresh you the reader on the specifics of gaps and techniques.

Techniques are identified numerically, as diagramed below. For instance, 9, 5, and 3 are outside leverage techniques. They specify the alignment of the defensive lineman in relation to their offensive counterparts.

Gaps, as suggested by that naming convention, refer to the areas between each of the offensive linemen and are labeled alphabetically. Depending upon their alignments, defensive linemen and linebackers are responsible for filling one or more of these areas.

Fundamental to every 3-4 defense is the play of the nose tackle. Generally lined up in 0-technique, most nose men have two gap responsibilities (i.e. both A gaps). This means that the nose tackle must read the direction of the play based upon the movement of the center. Furthermore, he must also be big and powerful enough to control the center and occupy the guards as well. This leaves one of the linebackers free to make the play. If the nose tackle is unable to hold position at the point of attack and/or consistently occupy two players, the run defense will suffer greatly.

In the 4-3 there are two defensive tackles as opposed to one. In most base instances, each is responsible for a single gap (often the B-gap for one tackle and one of the A’s for the other). As a result, tackles in this scheme have more freedom to rush up-field as long as they maintain “gap-integrity.” While they still see double teams, they don’t see as many as a nose-man in a 3-4.

The 3-4 defensive ends, (whose technique often varies), are generally defensive tackles in traditional 4-3 defenses. In the 3-4, the strength of the DE is more important than his quickness. That is why bigger burlier lineman often mans those spots. They commonly line up on the inside-shoulder of the offensive tackles. As is the case with the nose guard, they must control the tackle (or guard tackle tandem) and prevent him (or them) from getting to the second level of the defense. Rushing the passer and outside contain are secondary to their occupying of blockers and holding their position at the point of attack. This allows the linebackers to flow to the play with less interference.

The 4-3 defensive ends, like 4-3 tackles, have more freedom to get up field. One caveat, though, is they MUST maintain outside contain (a responsibility that falls on the linebackers in a 3-4). They can never be sealed and must be careful regarding taking shallow paths into the backfield. A hard-charging DE can be susceptible to reverses and draw play. Finding an end quick enough to rush the passer, but still big and strong enough to hold up at the point of attack is one of the toughest jobs in football on both the collegiate and pro levels.

As you will see in part 2 (i.e. the linebacker descriptions) choosing either scheme is predicated more upon personnel and less upon the idea of one being superior to the other.

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