Early in the 1990, three wizards got together and drew up a scheme so complicated, so fantastical, that any man who dared study it went mad after only two weeks. It was so beautiful, but ruthless, so that anybody that made direct eye contact with it had their eyes torn out by feral wildcats.
The desert swarm. Simple in it's complexity. Most ancient scholars that knew its innermost workings are long deceased. Only three remain. Two now work for us. What follows is the story of the two brave men and how their knowledge will affect us.
So what is the swarm? Basically, it's 7 undersized, interchangable players that can stunt, blitz, and drop into coverage. The DL have to be small and quick to survive in coverage. To counter the lack of size, the defense highlights it's quickness with stunt, kind of like Cameron Diaz's acne and airbrushing.
Take a normal, I formation lead against a overshifted 4-3:
Those two red areas indicate "bubbles" in the defensive front, i.e., gaps that have no defender lined up in them. These are typically what a running play would attack, since it's much easier to maintain the integrity of the bubble than drive a lineman out of the way:
A team with big, talented lineman can just beat the blocks at the LOS, or even drive the OL back into the hole, completely closing it. The University of Arizona did not have the luxury. The city of Tuscon had more snowstorms than nose tackles, so much like Bill Walsh in the 60s, the coaching staff set to work to find a way to compensate for what they did have. Thus, the stunting, wild, desert swarm was born. How would they stop they play? No one way in particular, but something like this would work:
The end uses his speed to cross the RT's face and close the gap, and the LB stunts around to fill the vacated gap. This is the defense shifting the bubble. The FB either just blocks the first person he sees, which is the end in this case, or has to stop, find the hole, and adjust. In this case he just blocks the end, leaving the stunting LB to make the play. Even if the FB can slide out and hit the LB, there is no more bubble because of the aggressive charge of the LB. The RB has to spill outside, leaving either the pursuit or the containment of the OLB to get him.
This is the basis of the swarm, using 1 of 4 LBs to add to the 3 man line's rush to confuse and attack. Even the safeties got involved. Somehow, somewhere, there would be 4 or 5 men coming and the QB has no idea where they'll be, leading to many an Eli Manning moment.
At Texas, a coach has the luxury of NFL type defensive linemen. We don't need to go full bore with the stunting and blitzing to win games, but we are still seeing a few things that run off the same principals. The big difference is that we run a 4-3, meaning that we already have a base, 4 man rush. This is where our quick defensive ends come in:
So we get a stunt from Bobino as Jones drops off into coverage. At it's surface, it's just a zone blitz, but it does a lot more than that for us. At Arizona, every matchup had to be carefully orchestrated to maximize what talent they did have. We are doing the same thing. Look at what this is doing for us:
As you can see from this diagram, this stunt gives us isolation for our two best players up front, Okam and Lokey (Okam is on left of the center, Lokey on the right). Okam uses his speed and size to tear past the guard, and the LT is focued on the dropping end and is too late in help. In Lokey's case, he gets free of the center double team because the center has to focus on the stunting Bobino. Lokey uses his 900 pound squatter's body to push into the backfield and collapse the pocket.
And that's how the swarm is helpng us now, getting us favorable matchups and creating pressure without putting stress on the back seven by putting them on islands. We'll see more variety as the season wears on because the matchups will change. Maybe we want our MLB to attack a guard instead of center. Whatever. Keep and eye out for it as the season progresses.