In the mid-90's, the Steelers were the only team in the league primarily running a 3-4 defensive scheme. Even up until a few years ago, you could count the number of teams running a 3-4 defensive scheme on one hand.
This year, fourteen teams will be primarily running that defensive alignment. The trend line is up and will likely remain up for the next few years. Based on the continued success of the teams running this scheme, it is not inconceivable that the number could top out at around twenty teams using this scheme after a couple more seasons.
Several of the defensive players drafted high by teams running 4-3 defenses fit better in 3-4 schemes, likely heralding more changes in the future.
The primary reason for the shift is that success breeds imitation. The other factor is that when teams are looking for a new coach, they look for coordinators from successful teams. Not too many coach-needy teams were scouring the Detroit Lions' coaching staff in search of their answer.
Many of the most successful teams in the league right now, such as the Steelers, Patriots, and Ravens, are running a 3-4 scheme. Their coordinators and defensive assistants will remain in high demand around the league.
When the coordinators from these teams move on to head coaching jobs or when the assistants bump up to coordinator jobs, they will instill a 3-4 scheme. And that trend is not confined to defensive coordinators. Offensive coordinators from these teams who bump up to head coaching roles will also look to instill a 3-4 scheme. Why? Because in this pass dominant era of NFL football, the 3-4 offers more options for attacking the offense.
But, the 3-4 defensive scheme relies on far different types of players in its front seven than a 4-3 scheme. One of the most pivotal players required to be successful as a 3-4 defense is a mammoth, super-sized nose tackle, who demands constant double teams from the offensive line.
While the outside linebackers are the high profile playmakers of the system, they rely on the mammoth in the middle to occupy blockers so they can run free and make those Sportscenter highlight plays.
These guys are not a dime a dozen. In fact, there aren't many of them at all. In the 2009 draft, there was only one really solid 3-4 nose tackle prospect, Boston College's B.J. Raji. He was snapped up by the Green Bay Packers, a team moving to a 3-4 scheme this year, at No. 9. With so many teams switching to a 3-4, elite nose tackles will not make it out of the first half of round one.
For that matter, even when there were only a few teams running the 3-4 defense, most of the quality nose tackles were grabbed in the first round. Some of the more recent teams who have made the switch, such as the Cleveland Browns, have not been able to find the answer at the nose tackle position and their defense has suffered for it.
This is why the Steelers absolutely can not afford to let Casey Hampton leave town after this season. He is way too important and finding his replacement will take time.
There are a few knocks on Hampton. One is that he is on the wrong side of 30. So what? The guy is 31 years old. He likely has three to four good years of football left. That buys plenty of time to find his replacement.
Another complaint is that he shows up to camp out of shape. The guy is roughly the size of a truck, and he is paid to essentially be an immovable force. Should the fact that he shows up a bit out of shape really be that shocking?
If I carried around the girth required of Hampton to be successful at his job, I'm not sure I'd be able to walk ten yards without being winded, let alone play on nearly every down of a brutal football season.
The guy has a constant motor, never takes a play off, and causes major headaches for opposing offensive lines. And this guy is a classic Steeler. He loves it in Pittsburgh and has expressed his desire to finish his career there.
Is he as good as he was during his first few seasons in the league? No. There has been some decline. He is no longer as fast running down the line in pursuit of ball carriers. I remember watching him chase down Titans running back Eddie George before absolutely burying him, causing a fumble. He doesn't make as many of those kind of highlight reel plays anymore.
At one point, he was the premier 3-4 nose tackle in the league. He has reliquished that honor to rival Baltimore Ravens' nose tackle, Haloti Ngata.
But, he is still plenty good. And his constant effort in the middle of that defensive line is one reason why so many of the other Steelers' defenders are so successful.
The Steelers have some tough choices ahead of them and many people are predicting that one of those choices will be to let big Casey go. I was one of those people before this year's draft.
But, after seeing how hard it will be to find his replacement with the re-emergence of the 3-4, the Steelers should resign Hampton for three to four more years and immediately start looking for a viable replacement to develop behind him.
If that means that the team needs to let somebody else hit free agency instead, so be it.