The Seven Diamond, or 7-D is an archaic defense from the dawn of football time. When our ancestors were small, hamster-like creatures trying not to get stepped on or eaten by the gigantic lizards around us, those lizards were using the 7-D to shut down the T-formation. Does that mean it's outlived its usefulness? Most definitely not. The 7-D is still an effective, simple and easily taught defense for youth football, or goalline/short yardage at higher levels. 

As you look at the diagrams, you'll notice a couple of things. First off, it's very similar to the Gap-8, and second, this is a run oriented defense. 

Since the offense is required to have at least seven men on the line of scrimmage the potential is there to play each man head up, and slant the defenders to a particular gap, Unfortunately, doing so with only a single linebacker means that against some formations the poor kid has to cover a gap six yards away. Instead I recommend only using the noseguard and middle linebacker in your stunts, as in Figure 1.

Figure 1: 7-D slants. 

I have never used the 7-D except as a changeup from a fifty front in goal line situations at the high school level, where it has worked remarkably well. I am reasonably familiar with the defense, and I've toyed with the idea of using the 7-D as a "passing defense", from my Gap-8 but never had the opportunity to do so. 

By shifting out of the base front, a variety of different pass coverages and stunt schemes can be used. Figure 2 shows a few different possible looks from this same defense. Notice that the basic responsibilities have not changed, only the alignment of the defense.

Figure 2: Different 7-Diamond Fronts

In the Eagle front, it's a good idea to shift the corners slightly inward to strengthen the off tackle gap. 

The basic assignments of the defense are very similar to the Gap-8:

Another version of the 7-Diamond that is worth looking into is the 7-Box. Figure 3 shows the 7-Box.

Figure 3: The 7-Box

In my opinion, the more effective pass defense would be the 7-box, because of its ability to cover each of the eligible receivers man to man, and still leave two deep defenders in zone coverage. The only drawback is the pass rush has been reduced from the six rushers of the Gap-8, to a mere five rushers.

If you have the talent and the ability to coach it, the 7-Box also lends itself easily to the idea of zone pass defense. Treat Sam and Rover like corners and give them responsibility for the outermost passing zones. Mike and Will cover the short "hook" or "drop" zones, and use the free safety and strong safety in two deep pass coverage. 

The responsibilities of the defense are virtually identical to the original 7-D, and it would be quite possible to use this front as a situational change from the basic 7-D. With two safeties deep Willie and Mike can cover the first back out to their side. While this does leave the fullback uncovered, many youth level teams leave him in to protect the quarterback. Additionally, you could work with the defensive ends to drop into coverage on the FB if he comes to their side, a technique that coaches of the Buddy Ryan "46" will find familiar. The remaining defensive end rushes the quarterback as normal.

The seventy front has many advantages for the youth game. While this system is very basic, it serves to demonstrate how effective the system can be with the right players.

Good luck.

~D.