Summer School 2021: Why spacing is critical on offense

How offenses can use spacing to manipulate defenses

If you’ve been following along with our Summer School series in 2021, you might have noticed a phrase or concept cropping up throughout our look at how offenses deploy their skill position players.

Over the last month we’ve gone over offensive personnel sets with three receivers (11 personnel), two backs (21 personnel), two tight ends (12 personnel), and four receivers (10 personnel). Taken as a whole they make up the four most popular personnel sets in the NFL today — or at least through 2020. Each of these personnel groupings has a number of unique strengths and weaknesses, and different ways to attack the defense.

Each of these personnel groupings also has different ways in which they tend to present themselves to the defense. The way those personnel groupings tend to line up will force the defense to counter. Put simply, if an offense running 11 personnel lines two receivers up out wide and one in the slot, the defense has to send a cornerback to cover each of the wide receivers and a third defensive back (usually a slot corner) to account for the slot receiver. This is the sort of thing that seems patently obvious on the face of it, but the offense can use that simple footnote to manipulate and make life difficult for the defense.

While many offensive formations look similar, how broadly teams line up can vary wildly. At the long end of the spectrum, the Miami Dolphins had the widest average formation in 2020, averaging 28.9 yards across. At the opposite end, the Los Angeles Rams averaged the tightest formation, averaging 21.1 yards across. That’s a difference of 7.8 yards, or to put a point on it, the widest average formation was over 98 feet across while the most condensed was 66 feet across.

When we look at it that way, we can see just how profound an effect offensive alignment and spacing can have on a defense.

Let’s take a look at how offenses are able to use spacing to their advantage.

Spread alignments

When analysts and commentators have talked about spacing over the last decade or so, they have generally been doing so with respect to the “spread offense.” While some concept names in football can be somewhat obtuse, like “Tosser” or “Smash” concepts, with meanings that might not be readily apparent from the name, the Spread Offense tells us exactly what it is. The Spread Offense seeks to use wider alignments and attack defenses with spacing.

A quick and dirty diagram shows how wide alignments can spread out the defense and create voids in coverage.

Here we have a fairly standard 2×2 spread alignment, with the defense playing a fairly standard 4-2-5 under nickel defense under a Cover 3 shell. Per PFF, the 4-2-5 nickel is the most common front and the Cover 3 is the most common coverage shell in the NFL.

The 4-2-5 Under nickel front and Cover 3 shell make for a defense that’s balanced counter to “standard” pro style 11 personnel sets. With three deep zones that defense can guard against vertical offenses, while its ability to have a natural eight-man box (with the strong safety at the second level) allows them to win most numbers games in run defense — or have an extra rusher or two for blitzes.

However, as we can see above, using wide alignments forces the defense to spread out from their preferred alignment.

Spreading the defense out offers several advantages for the offense. The first, and most obvious, of which is the opportunity to get their athletes in space with more room to work. Defenses have the luxury of being able to rally to the ball more easily when they’re able to operate in a more neutral alignment. Safeties don’t have to run as far to come downhill, cornerbacks aren’t quite on the same islands with their receivers, and linebackers aren’t responsible for as broad coverage zones. Spread alignments force defenders apart, putting reinforcements further away and forcing a greater athletic burden on individual defenders. Not only are safeties and linebackers responsible for more of the field, but they have to run further to help out their teammates.

In those cases, if the offensive player can find open field — or make a defender miss — there’s a much greater opportunity for the offense to create a big play.

Likewise, spreading the defense out turns smaller holes and seams in coverage into much larger voids. Offenses thrive when they’re able to put skill position players, and therefore the ball, where defenders aren’t.

In the above example, we have a defense running a Cover 3 defense which balances run defense with preventing vertical strikes. However, Cover 3 sacrifices the ability to defend the hook/curl area, the flat, and a vulnerability in the seams between the deep coverage zones of the corners and safety. The offense could use the tight end or slot receiver in the hook/curl area after using the wide receivers to clear out any underneath defenders and release the running back into a flat route.

Keen-eyed observers will also note the other advantage of spread spacings: It opens up the running game.

In the example above, we’ll notice that the spread alignment forces the defense to take linebackers out of the tackle box, leaving just five defenders between the tackles. We know, both from analytic studies and from simple logic, that running backs have their greatest yards per carry average against light (six or fewer) man boxes. By forcing the defense to keep just five or six defenders in the tackle box, the offense is able to create a numbers advantage for the running back. If the offense is able to account for all the defenders in the front, the back should be able to make good yardage before a defender will be in position to make a play on him. This is why many spread teams, particularly at the college level, almost always use an inside zone running scheme.

Of course, just as every defense has weaknesses, so does every offense. Spreading out the offensive formation, and moving the tight end away from the offensive line in particular, puts greater strain on the offensive tackles in pass protection. While the offense does still have the running back to help in blitz pickup or to help with double teams, not all running backs are reliable pass protectors. Likewise, uneven ability levels at the tackle positions could create opportunities for the defense and prevent the offense from attacking deep.

Condensed alignments

On the flip side of the spacing coin from spread alignments are condensed alignments.

We tend to think of condensed formations as running looks. The offense lines up with the tight end (or tight ends) tight to the offensive tackles, the wide receivers inside the numbers, and we’re expecting a hand-off between the tackles. But as with the 21 and 12 personnel groupings, modern coaches have found ways to pass in what should be an obvious running situation.

Here we’re moving to a 12 personnel set on the offense to double down on the running look and convince the defense to field a “base” personnel grouping.

That isn’t necessary for a condensed formation, but I chose to use it here to accentuate the tight personnel grouping. An offense could certainly run a similar formation out of 21 personnel or 11 personnel with a bunch set close to the offensive line.

As we saw up above, there are excellent passing offenses playing out of condensed formations. The Kansas City Chiefs, for instance, made heavy use of condensed formations following their selection of Patrick Mahomes.

As we saw in previous installments of this year’s summer school series, heavier personnel groups can be efficient for passing. That’s because in part because of the athletic mismatches modern tight ends are capable of creating, but it also creates natural traffic which defenders must navigate.

By grouping eight or nine defenders close to the tackle box, the offense is able to use route concepts which put defenders in conflict or force them to run around each other.

The “mesh concept” is an excellent quick passing combination which sees two receivers running shallow routes between the linebackers and defensive line in opposing directions. Against zone coverage they force defenders to communicate and effectively pass off receivers as they pas through zones. Against man coverage, the mesh concept all but demands one of the coverage players give up separation.

Condensed formations can also be an effective running look despite concentrating defenders in the middle of the field. In this case, the offense would be looking to off-tackle runs, taking advantage of the space to the outside of the formation. Off-tackle runs have a few advantages when run out of condensed looks, the first of which is the similar “traffic” issues as the defense has to deal with against the pass. Different defenders will naturally run at different speeds, and slower defenders can get in the way of their quicker teammates, making the entire defense slower as a result.

But also, by concentrating defenders in the middle of the field, it can force defenders to be out of position for toss or pitch plays.

Athletic runners can be able to get outside of the contain defenders by the time they get the ball, giving them plenty of room to run as they turn it upfield. Likewise, condensed formations can be effective with jet motion (that is, a receiver running across the formation, between the offensive line and the quarterback just before the snap of the ball) as well and fore similar reasons. The defense is forced to honor the possibility of a run with jet motion, potentially creating conflicts and traffic at the second level, as well as inserting misdirection into the play. And, similarly to a toss play or an off-tackle run, a jet sweep gives the ball to an athlete in motion towards space while forcing the defense to flow toward the sideline.

Final thoughts

Football, both at the collegiate and NFL levels, is a tightly regimented game with exacting rules. Even if the question of “what is a catch?” has somehow morphed into one of the great philosophic quandaries of our time, governing bodies carefully regulate everything from game length, field dimensions, to how many players can line up on the line of scrimmage.

But within those regulations we have seen some incredible variety in how teams can operate and play the game. On the offensive side of the ball, before we even get to things like blocking schemes, running lanes, routes and route combinations, play designers have massive latitude for creativity. We’ve looked at the most popular combinations for how teams can deploy their skill position players and seen how many options are available to coaches. There are so many combinations and permutations in personnel groupings and even how those players align on the field that it’s little wonder that some playbooks can be massive, ponderous things.

One of the truly remarkable things about football, particularly at the NFL level, is the sheer breadth of options available to coaches when it comes to gaining an advantage over the defense. Despite everything the NFL does to force parity onto the league, more creative coaches can find almost infinite wrinkles within the rules and exploit them. And while it might not be readily apparent to the casual fan, even something as simple as how close receivers are to offensive tackles — not to mention how many receivers, running backs, and tight ends the offense fields — can have a profound effect on the defense. It’s through exploiting nuances like these that coaches can set their players up for success even before the snap of the ball.