Who doesn’t love the Tennessee Titans’ Colin McCarthy? As a rookie 4th round pick, he came in and seized the job, became a tremendous run stuffer and impact player, and generally tore it up. In the preseason this year, he recorded 3 interceptions in 3 games and made enormous stuff after stuff in the run game. He appeared well on his way to becoming the star of our defense. And then he suffered a big ankle injury against the Patriots, and suddenly, our defense looked a lot worse. McCarthy was critical to our defense in a number of ways, and it appears that Gray built our scheme around his abilities.
Jerry Gray, throughout most of this year, has tried to run a two deep safety zone scheme. Like the old Colts system, and the famous Monte Kiffin Tampa-2, this scheme needs a high level MLB to run efficiently. And with Witherspoon filling in for McCarthy, we suffered a scheme collapse.
Two deep safety schemes, especially with zone corners, have a number of benefits- first and foremost, they take away the big play potential of the opposing offense. Dropping two deep safeties limits long runs by allowing the safeties to approach at full speed and to give the more time to adjust to the ball carrier’s route. It limits deep passes (I don’t think I need to explain how).
The scheme also maximizes the value of a 4-man rush and creates turnovers, if executed well. Tight zones by the corners and linebackers take away quick routes and early options. Zones allows these players to jump on routes and watch for screens, by letting them keep their eyes forward instead of having to turn and run with receivers. And that stands true, even with our terrible year; the Titans defense has allowed twenty-three 20+ passes, three 40+ passes, five 20+ runs, and just one 40+ run. All of those are in the best ten in the league.
But the scheme has one massive weakness- in between the numbers, from 8 to 20 yards deep. This is opposed to a Cover-1 system, where the strong safety controls the zone behind the linebackers. And this is why the MLB is such an important piece of the 2 Deep System. The MLB has a two fold duty− stuff the run, and drop into the deep zone normally occupied by the SS in a Cover-1.
This requires both a high level of athleticism and a high level of awareness. The MLB has to immediately diagnose the likelihood of the run, then find what receivers will be coming into the zone and shade towards them. McCarthy is not the best cover linebacker in the league, no does he have the best athleticism. But he has incredible instincts, and an ability to diagnose superior even to Keith Bulluck.
And we saw the results over the course of six games; tight ends, even 2nd and 3rd stringers, became fantasy must-starts against us. Slot receivers had field days, even as we shut down the outside. Teams didn’t need big plays against us; the simply churned up the field, 10 yards at a time. Our run defense was still decent; while we gave up a lot of yards, we were league average in yards per carry. But without McCarthy, we couldn’t cover that zone, and we suffered greatly as a result.
The effects become clear once McCarthy returned. Against Indianapolis we had our best defensive result of the year to date, even though McCarthy was still hobbled. The Bears game was an aberration (because their offense started four drives within the redzone− how can a defense not give up points then) and McCarthy played a reduced snap count.
Finally, we saw last week how the 2 Deep system was meant to operate; our linebackers shut down the interior of the field, we came away with 3 interceptions from them, and Tannenhill was constantly forcing throws and under pressure because the coverage left no one open for him.
With a healthy McCarthy inside, rather than the mediocre sub Witherspoon, we should see a lot more results like that.