I've tried to give you a good historical and schematic overview of the 4-3 Under in general and with regard to how the Seahawks run it. I now want to give you just a basic look at some of the coverage schemes that you will see the Seahawks running in tandem or independent of the base 4-3 Under. I'm not going to get into too much detail but I'll show you some of the basic tenets of each and explain what each player needs to do in each call.

Obviously there are many wrinkles to each formation and the coverage responsibilities change based on the personnel on the field and the opposing offense, situation, and defensive playcall. This is just meant to give you a basic outline and does not in any way attempt to cover everything the Hawks do on defense. Furthermore, their defense is one that continually evolves over the course of a year so it will be interesting to see how much it changes in 2011. With that said, let's take a look at some of the coverages we'll see.

The first basic coverage scheme is the "Cover-1". The Cover-1 is characterized by one safety in the deep middle of the field, and it's his responsibility to make sure no one gets behind him and the ball isn't thrown over the top. It's called a Cover-1 because he is the one player in zone coverage in deep centerfield. Here is a diagram of what it looks like in Pete Carroll's defense:

As you can see, if the WRs are out to the weak side of the defense, the free safety, typically Earl Thomas, will creep in and play man coverage on the weakside slot receiver. The strong side safety will come back and play the middle third of the field in a zone coverage read and prevent over the top throws. This is a diagram of what we've been talking about when we say that Mark LeGree was brought in to play the deep centerfield. It allows Earl Thomas to do more things and get up close to the line to blitz or play man coverage.

Because the SS is responsible for the middle deep part of the field here he needs to be a ballhawking kind of player and it's why you see the Seahawks putting so much emphasis on that attribute. He needs to be able to read the QB and predict where he's going with the ball because he will have to cover a lot of ground in order to force turnovers and pick off passes. It's called instinct, folks. It's why you will see more sets on the field featuring smaller, more agile and speedy safeties rather than one speed player and one run-stopping enforcer like in a lot of NFL defenses.

If the opposing receivers are set to the strong side the SS moves down into man coverage on the slot receiver and the free safety drops back into middle field coverage. In the Cover-1 defense the cornerbacks will typically play press at the line, with inside leverage on the receiver. On the snap, they'll force the WR to the outside and play bump-and-run with them - this forces the QB to make a very tough throw to the weak spot in the defense over our typically very tall cornerbacks. If they fail in their press jam at the line and the receiver gets to the inside, it makes things difficult for the free safety as he has to choose which route to jump on. Because of this you see the Seahawks stockpiling big, strong and physical corners that can handle the jam effectively.

These are just two examples of offensive sets and the coverage schemes that go along with them but serves as a good base to what you can expect to see. Obviously, the Hawks will change things up a lot to confuse the offenses but the thing to take away from cover-one scheming is that both the safeties have to be very instinctual, versatile players that are good in pass coverage but also thump in run defense.

The Cover-2 defense is characterized by two safeties playing the deep halves of the field like shown below in it's most basic form:

The field is split up into zones and the safeties play the deep halves. The corners are responsible for the flats on each side, meaning they take passes into their zones and help a lot in run support. This also lends to Carroll's belief in tough, physical cornerbacks. Obviously the sets and responsibilities vary here but this is the general look of it.

The Cover-3 is similar to the Cover-1 except the corners are also responsible for the deep third of the field on their side as well, putting 3 guys over the top in pass defense. One scheme the Seahawks run a lot is called the Tampa-2. It's a misnomer in the fact that it's actually more of a Cover-3 in that the middle linebacker drops into deep third coverage and the two safeties split out into the deep thirds of the field towards the sidelines. Here's how it looks:

Because the Mike linebacker is forced to play deep middle third of the field you need to have a very athletic and rangy MLB. Also, this defense gets the corners more involved in the run support game as well and you'll see corners with high numbers of tackles on teams that run the Tampa-2 a lot. The Hawks run a variation of the Tampa-2 called the Tampa-2 Nickel where they substitute out the SAM linebacker for a nickel defensive back. It looks like this:

The red boxes represent the zones each player is responsible for and the yellow boxes denote the soft spots in the coverage. You'll often see Roy Lewis or Jordan Babineaux in the Nickel (N) role - playing up on the slot receiver and following him through his zone but then will pass him off once through his area.

The Hawks "Bandit" package is an extreme variation of this to be used in obvious passing downs. The set is basically a 3-1-7 formation - there are three down linemen, a middle linebacker, typically Lofa Tatupu, and seven defensive backs. Typically, safeties are replacing the linebackers so they can run in pass coverage but still help in run support if need be. With seven defensive backs on the field - many of them interchangeable, it confuses the opposing offense and gives the defense an opportunity to blitz from many different angles. In 2010 you saw Kam Chancellor, Jordan Babineaux, Lawyer Milloy, and Roy Lewis out there in addition to Earl Thomas and two cornerbacks, Lofa in the middle, and three down linemen. Sometimes they'd blitz with Milloy, other times he'd drop back into deep coverage. Sometimes you'd see Lewis running in on a corner blitz. They mixed it up and it had some success. Milloy, for example, had 4 sacks in 2010 as a strong safety.

As Pete Carroll put it, "If you feel OK about your guys (defensive backs) rushing, which some teams don't, then they can rush, they can drop, they can cover backs. A guy who's on the line of scrimmage can end up being a deep defender and so you just give yourself a variety of things that you can do and interchange some parts and stuff and try to make it difficult."

"It's a fun package for the guys to play, because a lot of guys get to do things," Carroll said. "We're utilizing Lawyer in ways and Babineaux in ways that they give us unique stuff. It's nice also to get Kam Chancellor on the field in the package so that he can play some, there are just some things that he does well. Earl has some stuff that he does that's kind of unique, so that's all part of it. We're just trying to be very multiple in that because of the availability of the movement."

This success and commitment to DB-heavy sets is part of the reason that we've seen the Hawks bolstering their depth at the defensive back position. They've acquired Brandon Browner, Mark LeGree, Richard Sherman, and Byron Maxwell in the last few months to add to their corps there that already included Earl Thomas, Marcus Trufant, Walter Thurmond, Roy Lewis, Josh Pinkard, Marcus Brown, Kennard Cox, Kam Chancellor and possibly Lawyer Milloy, Jordan Babineaux and Kelly Jennings.

Keep an eye out for each of these defensive schemes in 2011 and take note of how often each one is run. It should be interesting to see what Gus Bradley and Pete Carroll plan to do with their new draftees and signees and I'm looking forward to seeing the continued evolution of the Bandit package.

Now that I've tried to lay out the different things the Hawks do schematically on defense, I'll go into the positional descriptions and what type of player Pete looks for at each spot. Stay tuned...