The Brilliant Nuance of Clemson’s Cover 3 Fire Zone

Welcome to your football offseason reprieve! I usually check in with you good folks more frequently than I did this winter, but we were all happily distracted by the basketball program earning some much-deserved respect. In fact, I was even relegated to “niche sport specialist” since Clemson is actually a basketball school now and we are thus a shootyhoops domain.

Yet I seem to recall being one of the few here to defend Brad Brownell a year ago and I have the screenshots to prove it, relegated niche sport specialist and all. As such, I want to quell rumors of my demise or that I “logged off” here and now, before I leap onto my Brent Venables Fanboy Soapbox.

This is the first of two 1500+ word articles I have for you boys and girls this week, plus a film review to follow the spring game, because this weekend is the oasis in the middle of a desolate sporting wasteland known as the “offseason.” Don’t mistake that for log off season either; I have not logged off and will never log off.

I was admittedly slow to start my annual dive into a new defensive philosophy/tactic to explore and explain, partly because I didn’t know which to study until recently. I could think of little which enthused me enough to hammer out 2,000 words beyond reiterating what I wrote two years ago on the 4-3 Over Front, Linebacker Keys (Illuminati Confirmed), and the DIME OF DOOM. Seriously, click those hyperlinks; they detail a core philosophy for each level of Clemson’s defense, to an extent, so they’re an excellent place to start if you’re new to STS or defensive football’s inner-workings.

My wintry writer’s block and/or intellectual laziness is a thing of the past, and my presumed offseason musings became a full blown film study on steroids when I saw this tweet:

In layman’s terms: Venables called a cover 3 fire zone blitz before the running back split out to the boundary, creating an empty set. The defense then checked to man coverage on the boundary side yet remained in a cover 3 fire zone on the field side. Meaning, this is a blended coverage: man cover 1 with a Will bullet blitz on the boundary side; a Cover 3 Buzz on the field side. A fire zone is the term used when a blitzing linebacker or safety replaces a lineman in the pass rush, and said lineman drops into underneath coverage.

No longer was I simply going to write about how Clemson relied on a 4 man rush far more often than in 2015 and 2016 (most “blitzes” were actually this same fire zone where a linebacker would blitz and a DE would drop into zone coverage, which means Clemson showed pressure but still rushed only 4). No, since I do a rather large chunk of the film review myself during the season, this boundary side man-to-man (M2M) constraint was an absolute banger of a wake up call. Not because I didn’t know this existed or that Clemson used it, but because I didn’t catch it myself.

Film review in-season is usually crammed in on Sunday and Monday evenings so I have time to research and then write the opponent scouting report on Tuesday and Wednesday, before that publishes on Thursday or sometimes on Friday. Using the play above as an example, in-season I would see Tre Lamar split out in man coverage with the running back motion and assume it’s a simple M2M Cover 1 Will bullet; great, quick and simple, 1 play down, 150 more to go.

On the boundary side this would be correct; Lamar is aligned on the running back, Mullen on the tight end, Joseph on a bullet blitz. But on the field side, it’s a Cover 3 Buzz coverage shell against Louisville’s 3-wide passing strength. With zone coverage against the passing strength, Clemson could throw more defenders at the 3-wide set, preventing a quick pass and mitigating the chances of being beaten one on one. Whereas on the boundary side, man coverage is less risky against a tight end and a running back (lesser regarded receivers). The coverage shell and fire zone worked perfectly since Jackson held the ball and Joseph blitzed cleanly. All which could’ve gone better would’ve been a sack instead of a throwaway.

To my shame, I missed this during the fall, leaving my psyche shaken and pride wounded. So I spent chunks of time over the past month rectifying my ignorance. In this column we will dive in with a closer look at Cover 3 itself and the most prevalent and successful ways in which Venables uses it in his pressure look.

The Cover 3 Buzz

It is well known here at STS that Venables and Clemson operate from a base 4-3 Cover 4, which lends itself to aggressive pattern match coverage outside and physical safety run support. Paired with the defensive lines Clemson has enjoyed in recent years, it is consistently one of the most feared and most successful defenses in the country. However, Venables is not a strict Cover 4 adherent like a Pat Narduzzi at Pitt, who lives and dies by his professed scheme. Venables likes to show pressure — whether he sends more than 4 rushers or not — and when he does it’s usually from a Cover 3 look.

There are different types of Cover 3 zones, which are differentiated by the defender who covers the curl/flat zone. In the Buzz coverage shell, where our focus in this column shall remain, it is the outside linebackers who take the curl/flat (in Cover 3 Cloud, the corner; in Cover 3 Sky, the strong safety).

The diagram and gif above show the coverage shell for Cover 3 Buzz and the coverage in action, respectively. This is the same coverage shell Venables uses most prevalently in his fire zones. It’s a common tactic in every defensive coordinator’s repertoire, used to confuse offensive lines and quarterbacks by making them guess where pressure will come from. With Clemson consistently boasting the best 1-gap defensive line in the country, it is borderline unfair for opponents and erotic for me.

Last offseason I wondered if Venables would blitz Kendall Joseph at Will as often as he blitzed Ben Boulware, and the reasoning here was that he wouldn’t need to mask Joseph in coverage quite so much as he did Boulware, who was at his best on bullet blitzes anyway. That, plus with what I knew would be an outstanding front, led me to expect fewer blitzes on standard downs. While Venables certainly didn’t blitz Joseph as often as he did Boulware, it wasn’t necessarily true he blitzed less often.

The first game I chose to revisit was Auburn; given Clemson’s 11 sacks, I figured Venables must have thrown plenty of fire zone at Jarrett Stidham. Though there were plenty of fire zone concepts, Venables primarily called cover 4 and M2M cover 1 even when dropping a DE into coverage and blitzing a LB or two. The 11 sacks were as much a product of Stidham’s rust and time spent in the air raid Big 12 (where he could hold onto the ball forever with little consequence) as they were Venables’ pressure or Clemson’s front.

Since a tweet about the Louisville strategy is what led me down this rabbit hole, I next chose to look more closely at the film from that oh-so-satisfying night. It makes sense Venables would want to confuse Lamar Jackson and Louisville’s perennially bad offensive line with pressure looks, but play safe on the back end with zone coverage to outnumber receivers and keep more eyes on Jackson when he inevitably found room to run.

And that’s exactly what Venables did. Clemson sent pressure from various angles without sacrificing coverage integrity on the back end, forcing Jackson into inaccurate throws all night:

And Dorian O’Daniel’s pick six? A Cover 3 Buzz Fire Zone, reminisce and admire:

Naturally, fire zones became Venables’ favorite blitz look on conventional downs in 2017; not merely from the 3rd down dime formation like we grew used to in recent years. Make a quarterback guess where an already fearsome rush is coming from, and you can make a Heisman winner look utterly lost.

So you can likely guess how that made our favorite Big Forehead Boi Jake Bentley look two months later (yes I’m looking at South Carolina purely out of derisive and deliciously fermented spite, fight me). After a few early vertical seam routes broke wide open between safeties in Cover 4, Venables adjusted and employed a Cover 3 Buzz zone with frequent pressure looks most of the night. We even saw the boundary M2M constraint against 3-wide, which of course Bentley misread:

Above you will again see Cover 3 Buzz to field, M2M Cover 1 Will bullet to boundary: O’Daniel covers the flat, Mullen a deep third, Smith and Ferrell hooks; Joseph bullet, Muse deep middle, Carter and Skalski in M2M on the tight end and back, respectively. Bentley saw cushion from Mullen and thought he had easy yardage against soft M2M, but O’Daniel was on his way to the flat to blow it up immediately.

After Venables adjusted to more Cover 3 fire zones to incite confusion, Bentley subsequently deteriorated further into sacks and misreads, in addition to to the early misfires on early vertical routes down the middle of the field against Cover 4. Had he not missed the early open seams, the contest may have been far more uncomfortable — for at least the first half — than the blowout it became.

With all but O’Daniel returning to Clemson’s starting front 7, whether or not Venables will feature the fire zone just as often in 2018 comes down to the development of Isaiah Simmons at nickel/Sam. O’Daniel’s abilities in coverage afforded Venables the luxury to show and send exotic pressures from the base 4-3; with Simmons’ size and speed there is plenty of reason to think he is the heir apparent to O’Daniel as the every down hybrid in the nickel/Sam role. If he acclimates as quickly as his physical attributes would suggest, the drop-off won’t be as drastic as I originally feared and we will enjoy the same fire zones this fall...but more on this later in the week.