*Keep in mind that Anders' first language is not English and he does not live in the United States.
In recent Nate Allen discussions, I have experienced that several people are unaware of how defensive coverages work and what the responsibilities is for the different players in those coverages (especially the safeties).
A common complaint I have seen here and on other blogs during the preseason, is that Allen was often far away from the football and therefore must suck. What those people forget is that we played a lot of Cover 1 or 3 during the preseason with mostly Cover 3 concepts.
In this article, I will try to explain what Cover 3 is, along with its strengths and weaknesses. I will then show some screenshots from some of the preseason games to show how it relates to the Eagles and the safeties. Sadly there is no all-22 from the preseason, so it will be somewhat limited in what I can offer in visuals.
What is cover 3?
Cover 3 is a zone coverage, where the deep part of the field is split into three (hence the name "Cover 3") between the two cornerbackss and the deep safety (original the free safety, but in now free and strong safety are interchangeable). The cornerbacks each have one of the outside zones and the safety has the 1/3 middle of the field.
In Cover 3 and Cover 1, the deep safeties reads are quite simple. First, they must make sure the tight ends and wide receivers don't get behind them. This is the cardinal sin of a deep safety.
After he sees that no wide receivers gets behind him, he has to run up and help tackle the player with the ball (whether it be a wide receiver on a short route or a running back on a run). This can therefore create the illusion that the safety is bum or a slow poke and should be benched, but in fact he just did his assignment perfectly. This is also why the "coverage" scheme of Juan Castillo was doomed too fail as he switched this, he first had them read run and then try to get deep.
Underneath is the zones split in 4 between the 3 LBs and the other safety. This can be seen in the picture below:
Strengths of the Cover 3
The primary strength of the Cover 3 is that it is a balanced cover scheme that is both good against the run and the pass. The reason for this is that you have eight defenders near the line of scrimmage and your back line is less stretched out (compared with a Cover 2).
As with every coverage, the Cover 3 has some weaknesses that can be exploited if the quarterback recognizes the coverage before the snap (yes, you can disguise it and have it look like a Cover 3, but in reality be a Cover 2 or 4). While the Cover 3 is good against the run and the deep pass, it is weak against the short outside pass (curl/flat area), because the WILL linebacker and the strong safety have a relatively long way to go to protect the zone.
Time for some preseason screen shots!
This is a good example of the Eagles playing Cover 3 against the Panthers. As you can see both CBs are playing 8 yards of the WR to be able to drop back into their deep 1/3 of the field. Also note how far the FS is off the ball just at the snap.
Below is how the play ended. Notice how far away the FS is at the end of the play. He started of at the Panthers 44 yard line. At the end of the play he is at the
56 Eagles 44 yard line and he was most likely deeper than that (He can run down towards the ball). There is a good chance the FS dropped at least 30 yards away from the line of scrimmage. If Cam Newton had not been flushed by a quick pass rush, there is a good chance he would have been able to hit a short pass for 6-10 yards on the outside and the FS would be at least 20 yards away from the play (longer if he lines up at the opposite hash mark).
So the next time you see an Eagles safety come in late towards a ball thrown short, there is a great chance he had had the deep zone or a zone on the opposite side and he was just doing his job.
I hope this helps clear the confusion about the job of the deep safety in Cover 3.