As we've detailed in this space, two-back running games from spread alignments combined with RPOs (run/pass options) are doing a good deal of damage these days. There was a time though when the spread seemed to be facing a bit of trouble.
The most common defensive scheme in vogue today is the 4-3 Over backed by quarters coverage, a system that allows defenses to control the edges and extra defenders flying to the football against running plays.
Before the spread-I formation and RPO came to steal, kill, and destroy it was a defensive system that allowed defenses to balance between getting aggressive play against the run and being in a sound alignment against the "4-verticals" passing play that launched the Air Raid into prominence.
It's probable that RPOs and two-back spread run games came into existence out of a need to stop these quarters defenses from being able to consistently get numbers advantages against the run and the pass.
So in the past, a 4-3 Over front team playing quarters could get after a spread team by responding to run blocking from the OL like this:
In this scheme the LBs are freed up to play very aggressively and flow to the ball before the OL's double teams can reach them because they (the LBs) know the safeties are going to be there quick to clean up behind them.
The defense could respond to pass blocking like this:
There's a few different ways quarters teams will instruct their DBs to play coverage but many of the options include bend don't break schemes like this one that make life hard for teams trying to throw the ball down the field.
If the corners are good on the perimeter and the linebackers and safeties are skilled at pattern-matching from quarters coverages the windows get pretty tight in a hurry for the offense.
When the defense can get those kinds of schematic advantages from their base defense, the offense has to evolve. Enter the two-back spread run game and accompanying play-action and RPOs that make it impossible for quarters teams to have those numbers advantages.
As Michigan State is repeatedly learning in their bowl games and non-conference match-ups with modern spread teams, you can't send the safeties downhill against two-back or RPO-heavy spread teams because they will shred your safeties with quick passes to the perimeter or even deep shots.
So the goal for 4-3 Over teams that play quarters coverage needs to be something that sets them up to continue to get numbers into the box but also be able to maintain numbers over the top when facing two-back runs paired with RPOs or play-action.
The solution came from Michigan State's "solo" coverage they play against trips formations that works like this:
It's a man/zone combination coverage where the defense gets four over three to the passing strength of the trips formation and then play man coverage on the weakside. It's the superior run defense option for stopping trips formations over something like "cover 6" which is the superior call if the defense wants to shut down passes to the weakside.
The benefit of "solo" was that the strong safety can play run-force on the weakside if his man wasn't running a vertical route. Of course when the RPO and spread-I came it was curtains for safeties trying to balance coverage responsibilities with run fits.
However, the defense has been tweaked in two ways that have made it less vulnerable to RPOs and two-back spread formations. The first tweak is one that more and more teams are now making, which is to give the DEs run-force duties when playing even (four-man) fronts.
That allows the safety to be an alley defender rather than a force defender, so he has extra time to read his keys and avoid having conflicting responsibilities to either side of the formation. The next tweak is to play this man/zone combo coverage against any two-back sets by assigning the safety to play the TE/H-back/FB in man coverage.
So against a spread-I formation running the dreaded counter play with pass options attached:
The defense is in much stronger shape, enjoying the benefits of playing two-deep coverage to the field side against the twin receivers while enjoying also the benefits of playing man-free over to the boundary.
The DE can play to force the ball inside where the linebacker is filling hard to blow up the H-back's block while the strong safety should be able to arrive fairly quickly since he's keying the H-back as well.The strong safety is also well positioned to help take away in-breaking routes from that solo-side Z receiver because he can read the play before filling the alley behind the linebackers.
Because the DE is handling the role of forcing the run, the defenders on the weakside can keep their eyes on their man coverage assignments and be okay whether the play turns out to be a run or a pass.
Oklahoma State mixed this in with their diverse arsenal of schemes last year and strong safety Jordan Sterns had his second consecutive season with at least 100 tackles. You can expect to see more teams mixing in zone/man combinations of this sort and relying on their DEs to force runs in order to achieve similar results.
Making it work
The key to stopping these smashmouth spread attacks is causing hesitation for the QB and buying time for the defensive backfield to read their keys and find the ball. If the offense can be allowed to go fast and play downhill then they will live up to the "smashmouth" moniker.
On the other hand if the defense has a chance to play base defenses that can allow them to get a numbers advantage against both the run and the pass regardless of what happens after the snap, then they can reclaim some of the advantage.
To make this style of man/zone combination work a defense has to have a few particular components. The first is a lockdown corner to play man coverage on the weakside. If the opposing team has an ace WR in that spot and love to throw him the ball on standard downs then this scheme is DOA without a corner that can match him.
The second is a pair of DEs that are fundamentally sound and good at responding to different blocks. If that DE can't consistently contain the ball inside on the weakside this scheme can get into trouble fast.
Finally, the strong safety should be a player worth featuring as a free hitter against the run game. This is an easier role than playing in the box or playing deep zone so perhaps one of the nicer things about this scheme is that it allows a defense to get a lot of mileage out of an instinctive, good tackling safety who doesn't have to be a superstar athlete.
Defensive schemes that depend on having uber-athletes at every position always run into trouble, it's better to have a system that can set up good football players that know where to be and love to tackle even if they can't break 4.8 in the 40 yard dash.
The best defensive coordinators evolve their approach to feature whatever uber-athletes they have in a given year while trying to set up the rest of the defense to have assignments that can be reasonably executed by fundamentally sound, hard-nosed players. For 4-3 defenses that have the players for it, this will probably be a common option for the next few years until offenses adjust again.