When Mike Tomlin was hired in 2007 to be the head coach of the Pittsburgh Steelers, two very different defensive philosophies came together. Tomlin was a Tony Dungy disciple, the Tampa-2, a 4-3, 2 deep safety system that was designed to get young athletic players on the field early and get the most out of their rookie contracts. Dick LeBeau ran a zone-blitz out of a 3-4 base that was heavily cover 3, it relied on veterans that could execute more than elite athletes, and the two systems used different types of players at almost every position.
Tomlin stuck with LeBeau and the cover-3, but there were signs that his time under Dungy, along with the trends of the modern NFL was creating turmoil. Tomlin wanted players to start earlier, he wanted to get more pressure with just 4 rushers. The team started throwing some cover-2 looks into the defense.
When Butler took over, many thought that was going to be Tomlin’s time to turn the defense into what he was used to. Instead we got to see a vision of defense that is even better. This defense uses cover 3, it uses cover 2, it uses man, pattern zone matching, and it uses a lot of creative pass rushes both blitzes and without blitzing.
Last season the secondary, with new faces and a new assistant coach, was able to support the system, and we can now see the defensive brain-child that the Steelers started when they brought Tomlin and LeBeau together in 2007.
So why should they change it?
I was looking at draft needs on defense and it was frustrating. The Steelers have 7 defensive lineman that played snaps last year. One of them played NT, and that man is Dan McCullers. The Steelers base 3-4 requires high end athleticism at the OLB position, and behind the elite athletic prowess of starters Bud Dupree and T.J. Watt there aren’t any players with the athleticism or coverage ability to be a major rotation player at that position.
Add to this the Steelers lost Mark Barron, who wasn’t worth his contract, but whose ability to man up on athletic TEs from the LB position is a key element to the defensive success last season, and needs to be replaced. Also they need a rotational safety, and one that specializes in deep zone defense, as that is the weakest part of Terrell Edmunds’ game and the Steelers want to move Minkah Fitzpatrick around more.
The Steelers can’t solve all those needs with their limited draft capital.
But what if they didn’t need to?
If you stop using a NT, then Dan McCullers is just space eating DT depth, and there is no need to draft a NT or play a DT out of position and hope for the best.
If edge defenders don’t have to be outside line backers than you don’t need a top athlete at the position to step in and be passable in coverage right away, you can use Olasunkanmi Adeniyi and Tuzar Skipper more and not have the pressure of playing in coverage at all, and that benefits Bud Dupree as well.
Right there you reduce the need for those two positions to be drafted to almost nothing. And they can do it easily. Just switch the base defense to a 4-3. Then you increase one need that already exists, replacing Mark Barron, eliminate entirely the need for a NT, and greatly lessen the need for any edge player to play in coverage right away.
I know switching to a 4-3 was something that was thrown around a lot in the past and isn’t discussed much anymore, but the personnel make sense now, and not just from the draft perspective.
Devin Bush is the first natural 4-3 MLB this team has had in a long time. Devin Bush is a classic MLB playing slightly out of position on the Steelers. Moving to a 4-3 would also get the most out of Devin Bush, while limiting opponent’s ability to get him matched up on TEs and RBs.
As the 3 man front is used less and less, it makes sense to stop having DTs play DE and keeping a NT for limited snaps, and no longer need edge rushers to drop into coverage. Just make the 4-man front the base. there’s so much variance that can still be found within the 4-man front, it won’t limit what the defense can do.
After 13 seasons, the time is finally right for Tomlin to switch the Steelers to a 4-3 defense.