All too often, cornerback and wide receiver matchups have more bark than bite. For all the talk about the matchup, it’s rare to see a corner truly shadow a receiver. That’s because it’s not really a great idea unless that guy is Darrelle Revis in his prime. Even if you have a perennial Pro Bowl corner like Jaire Alexander, it’s probably best to play holistic defense instead of letting the offense have one-on-ones all day.
Whatever the Green Bay Packers did on Sunday against the Minnesota Vikings, it worked. Jefferson only caught one pass for 15 yards on a frustrating day. Alexander lined up on Jefferson on 21 of his 33 reps, and we’ll mainly focus on those. Alexander’s assignments can be broken into four categories: pure man-on-man, deep-third zones, squat technique, and quarters. Those are my words for things you might know as something else, so bear with me as best you can.
I should mention that I did this charting manually, and I am certainly prone to mistakes. I’m sure I misdiagnosed a rep here and there, so take these numbers with a grain of salt. I’ve also organized this in a weird way, with Cover 6 (or Quarter-Quarter-Half) reps sorted into the same category as Cover 2 and Cover 4 reps to help us focus in on Jefferson and Alexander. If that bothers you, just send me your name, credit card number, and the three digits on the back, and I’ll make sure your concerns are taken care of.
You’ll notice that deep-third and man-to-man assignments didn’t show up much. That’s not how the Packers, who run a very similar defense to the Vikings, prefer to live. Like the Vikings, Los Angeles Chargers, and every other Vic Fangio-inspired defense in the league, the Packers prefer to call split-safety defenses. In those, Alexander will be in either a Quarters look or a Halves look to his side. “Squat” technique is what I’ve chosen to call all the reps with a half-safety to Alexander’s side, like in Cover 2.
This was Green Bay’s most potent weapon against Jefferson. In Cover 2, or the half side of quarter-quarter-half, the corner will never be responsible for anything deep. It allowed Alexander to jam Jefferson with impunity, leading to reps like this:
Taking a full step into the receiver’s body and thrusting your entire body weight into him can be dangerous business. If you can swat the jam away, you could end up in a hopeless chase.
But if you have a safety waiting to pick up every deep route anyways, that won’t matter. So jam away. That’s how the Detroit Lions and Philadelphia Eagles handled Jefferson, and I’m frankly surprised we haven’t seen more of these aggressive jams throughout the season. That sort of insurance policy takes Jefferson’s skillset out of the equation. He could be Captain Marvel, and it wouldn’t matter. Cousins can’t throw right into a half safety.
That point is often met with resistance, as if the dynamics of Cover 2 cornerback are somehow an excuse or minimization of the Packers’ game plan. In reality, that was just Green Bay’s plan manifesting the way they drew it up. Alexander won’t apologize for leveraging his assignment to get the most production, nor should he. Sure, it doesn’t make for the most level cornerback-wide receiver battleground, but the Packers weren’t interested in a fair fight. They were interested in winning the game.
The Eagles also run a Fangio-inspired defense and call this strategy on defense “Zeus.” I can’t speak to whether the Packers or Vikings use the same word, but they both have the same concepts in their playbook. The Vikings have the tools in their playbook to beat this kind of defense. Unfortunately, issues with their footing sabotaged much of their first half.
Up through this entire slip-sliding nightmare, Alexander was shadowing Jefferson. He wasn’t playing full man coverage, but he was following Jefferson around the formation. Interestingly, after the Vikings changed cleats, Alexander stopped shadowing Jefferson. That probably had to do more with the game situation (it was 24-3 by that point) than the cleats, but it’s an interesting coincidence.
If we want to hone in on a more true competition between receiver and defender, we should look to Green Bay’s most common look against Jefferson on the day: Quarters.
In quarters, the cornerback’s job the vast majority of the time will be MOD (Man Outside and Deep), MEG (Man Everywhere he Goes), or, against certain route concepts, a true deep quarter zone. That all depends on the route concepts, and we don’t need to differentiate them for our purposes today. In all of these assignments, the corner knows that he has help to the inside. In MOD, he’ll truly pass off any in-breaking routes to someone else. But even in MEG, he can play with outside leverage. He’ll have good position against anything that breaks outside, and anything that breaks inside is likely to have a safety or linebacker lurking around it.
Here’s Patrick Peterson using that advantage to slow-play an in-breaking route against Gabe Davis for a game-clinching interception:
It’s not as strong an advantage as you have when playing squat, but it’s still a little safer than playing pure man coverage. As the most common coverage, this was the bread and butter of Green Bay’s game. I think this is our best bet at truly comparing Alexander to Jefferson. The squat reps count, and Alexander deserves credit for some very good jamming at the line of scrimmage. So we can mark those down as a positive and set them aside.
We can further purify the sample by removing plays where Jefferson fell down. That’s not excusing them; Jefferson made a mistake in preparation and suffered the consequences. It’s not unlike if he neglected to study film on Alexander. Preparation is part of the game. But it doesn’t help us examine the matchup, so we’ll pencil them in as a negative on Jefferson and set them to the side as well.
Looking at all 33 of Jefferson’s routes, we can see just how much help the Packers gave to whoever was covering him, Alexander or otherwise. In the below chart, purple sections are for coverages that provide inside help. Yellow sections are for coverages that provide deep help. And green plays are man-to-man. You can see why Jefferson felt the need to point out how often he ended up in a bracket or functional double team.
Jamming out of squat technique and Jefferson falling down because of poor preparation are the two biggest takeaways, but it leaves more than half of the sample unaddressed. Without the squat reps and slips, we have 11 reps left over with Alexander aligned on Jefferson. Here they are:
I’ll break down each play individually on Patreon, but there are a few general observations worth sharing. First, although Jefferson slips a little on the first rep, the “robber” safety was lurking inside his route, so it didn’t matter. That characterizes a lot of these reps, and that’s by design. Many of these reps are impossible to throw, no matter how good Jefferson’s route is. The space Jefferson found was against Alexander’s outside leverage, which was irrelevant with the help inside, of course.
On the third rep, the one with Alexander’s griddy, I think he gets away with a little arm tug. Were I a Packer fan, I wouldn’t use that one as the best of Alexander’s day. Personally, I prefer reps like No. 6 and No. 11. When Alexander was in a true quarter zone, he sets a really good example of how to play it. He sets his feet at a 45-degree angle and is ready to break on anything Jefferson does. It’s not quite as spectacular aesthetically, but it’s really good corner play.
Conversely, you can see many examples of Jefferson finding separation against MOD coverage. Whether it’s something that breaks off underneath Alexander’s coverage like rep eight or an in-breaker like rep nine, there are absolutely throwing windows available, had the play come to that. Why the ball went elsewhere isn’t our focus. We just want to see that the ball could have gone to Jefferson if it had to.
Jefferson does a good job of stemming his route into Alexander’s body to maximize separation when he breaks inside. He uses his size to threaten the space Alexander wants to occupy, then his agility to break away. It’s now up to the inside safety to break on the ball in time — and he won’t always do that successfully.
If there’s one thing I’ve learned in all of my tape studies, it’s that nothing is ever as extreme as it seems. Alexander didn’t lock Jefferson away in a fairy tale tower, but it’s not like there isn’t a kernel of truth in that. Alexander did a great job with the assignments he was given. Jefferson didn’t properly prepare for the game’s environment, and once he had resolved that issue, he had a much easier time getting space. That means Alexander wins the matchup. But as long as Jefferson has learned his lesson about cleats, we have no reason to be concerned.