Once given the chance to become the head coach, many spread-option offensive coordinators will immediately hire a 3-4 defensive coach. Much like the defensive coach who wants to install whatever offense gave him the most trouble as a coordinator, spread-option coaches simply can't stand facing three down linemen defenses.
Their reasons are similar to those reasons that cause Tom Brady or Peyton Manning to struggle against those defenses in the NFL, it's not as easy to dissect opponents if you aren't totally sure what they are doing. The nature of the 3-4 is that it offers flexibility in which defenders end up performing which roles after the snap.
As difficult as this is for NFL QBs to decipher when trying to find the right coverage match-ups to attack, it's even harder for a spread-option team that chooses where the ball should go based on which defender is put into conflict by the play design.
Much of what has made systems like the Air Raid so lethal is the way the quarterbacks are transformed into machines that quickly process the defense and quick trigger the ball to the right playmaker. When their ability to quickly discern what's happening and act on muscle memory is disturbed, they can become ordinary very quickly.
Today there are numerous schools of three down lineman defenses that have a similar approach to that of the spread-option offenses and are evolving the classic 3-4 defense into something new, the 8-3 (coined by Cedar Park head coach Joe Willis).
While the spread looks to use space and options to attack their opponent rather than size up front, the 8-3 defense eschews trying to "line up sound and make 'em beat us" and instead looks to win on a mental level through disguise, dictation, and disruption.
It's ultimately a 3-4 defense in terms of positions on the field and pre-snap alignment, but instead of matching power up front with two-gapping DL, the 8-3 is defined by the eight stand-up players will shift around to assume different roles. It's descended from the 3-3-5 but uses more 3-4 alignments while bringing a similar philosophy of flexibility. It's the counter-point to the spread, using space and options to present conflicts and dilemmas to force the offense to play defense.
Flipping the script
Defenses have traditionally been defined first by how many down linemen are on the field and then by how many linebackers the scheme employs. The 5-2 "Monster" defense, the 4-3, the 3-4, the 4-2-5, they all follow this pattern.
But this point, defenses are actually designed from the top down with the coverage determining the front as coaches try to first ensure that they are in strong or at least sound position to stop the pass. Nevertheless, teams are still defined first by what they are doing up front.
The branding of modern varieties of the 3-4 as the 8-3 reverses that trend by defining the defense around the eight players standing up in the defensive backfield.
Teams relying on these types of schemes, such as Boise State, BYU, West Virginia, or now Missouri can play eight-man coverages, any number of four-man rush/seven-man coverage zone or man defenses, zone blitz, or bring the heat and back it up with man coverage and zero deep help.
The goal in finding and developing personnel is to find players that can perform as many roles in the defensive backfield as possible and having positional rules that will allow players to compartmentalize and play in multiple defenses.
Attacking with disguise
The obvious advantage of having eight defenders standing up before the snap is that it's hard for the offense to know exactly what you're going to be doing. So long as an 8-3 defense has simplified rules and a compartmentalized approach, in which players learn a few different roles in the defense and fill them in different calls, it's possible to throw a lot of different defenses at the offense.
That's useful for a number of reasons, first for preventing the offense from easily identifying which defenders can be put in conflict by RPO plays that punish aggressive run fits with a quick pass.
The 8-3 can morph into the 4-1 look that's become a popular anti-spread approach:
The difficulty in this defense is that the offense can put the outside linebackers, in this instance the Buck and Raider, in run pass conflicts with inside runs paired with quick outside passes into their respective zones. However, if the offense doesn't know which players will be in conflict until the moments immediately after the snap it becomes harder to exploit.
There offense also to be aware of the fact that there might not even be conflict defenders to target because either because everyone's dropping back:
Or everyone's coming:
There's a wide range of possibilities the offensive players have to be aware of before the snap which can create a mental strain that leads to missed opportunities if not costly errors.
Again, so long as each player in the defensive backfield knows how to fill a few different roles then the number of blitzes and defenses that can be thrown from the 8-3 alignment are numerous. Keying in on the weaknesses is difficult since the defense can shift players into the positions where they'll be best against a given opponent or hide when they'll be in vulnerable spots.
Attacking by dictating
The next advantage to building a defense around having eight stand-up players in the defensive backfield is the ability to dictate time and space to the offense.
In a 4-3 set, the defense has handicapped their own ability to deny angles or space to the offense since they have one fewer player who can easily move around on the field to address different offensive strengths or leverage advantages. Let's say the opposing team has a very good slot receiver they rely on to get open in the middle of the field to move the chains:
They can rotate into a three-deep zone that brackets that slot receiver with the outside linebacker and down safety playing zone with their eyes on him while the inside linebacker and deep safety help inside. Where is the slot receiver going to find open grass with all of that attention focused his way? The offense will have to look elsewhere and they'll need to do it before the blitz gets home.
Let's say that the team's most dynamic feature is the QB and his ability to run the ball on zone read concepts:
With the end slanting wide and the whip outside linebacker sitting in the flat the QB will have a clear "give" read on the zone-read and the running back will be forced to make the play happen while the inside linebackers are freely keying off his movements. Once again, the offense is forced into a position where someone other than the star is forced to make the play while the defense defers their own stress point somewhere manageable.
In this instance, the slot receiver has a lot of space to work in but with the QB's eyes focused on the back side he's unable to take advantage. To successfully attack this defense the offense will have to start calling something else.
The 8-3 defense can also align in one call to encourage a response and then shift. Perhaps the offense's favorite check at the line when they see the defense lining up to deny the QB a chance to run the ball is to call a quick game concept that features the slot receiver, but the defense anticipates this and drops back after the snap to smother the slot receiver with zone defenders.
The spread offense is no longer playing a cat-mouse game where they force the defense to pick their poison but are now drawn into a chess match.
Attacking with disruption
Teams love specialization of personnel as it allows them to form systems that draw tremendous value from a unit and get a sum that is greater than the parts. You can see the art of specialization at work on the offensive line where units are typically broken down as follows:
Left tackle: Athletic pass protection specialist who protects the QB's "blindside."
Left guard: Quick in pass protection and mobile to either reach block the backside of a play or pull to the strong side on a run scheme.
Center: Good with calls and with getting the snap off cleanly before helping double team a DL.
Right guard: A straight ahead mauler, best at moving the pile in the run game.
Right tackle: A more athletic mauler who can dominate the edge on a running play.
This standard breakdown holds true for many lines and it's designed to combat 4-3 fronts. Overall they want to be able to hold up to pressure on the left side and blow you away on the right and they are best designed for handling strong 3-tech tackles or blindside edge rushers.
The 8-3 doesn't put all of its eggs in one basket in the pressure game and the fact that so many different players are in stand-up positions makes it easy to move them around and attack where ever the protection is most likely to break down. With four linebackers near the line of scrimmage it's a simple matter to bring numbers and overload the softest part of the offense's protection, even against spread sets that can counter with hot routes:
The defense can show pressure on the edge from the middle linebacker before the snap, but after the snap they drop three shallow zone defenders to the trips side to take away the quick hot routes as well as another linebacker underneath the X receiver to prevent a quick route from him.
Meanwhile the nose and left end slant inside, requiring some careful communication and movement from the center and the right guard to prevent one of them from quickly blowing through the middle and wrecking the play. Then the buck linebacker crosses the right guard's face and looks to turn up field for quick pressure. The running back and right tackle are likely concerned with the middle linebacker first and so the blitzing buck has time to attack and his movements are shielded by the DL's slant and the middle linebacker's feint.
Blitzes like these are challenging for an OL to pick up, particularly if the attacking players are explosive athletes who know how to disguise their movements, and the 8-3's structure allows these blitzes to attack the OL that are least effective in pass protection.
Even if one the boundary outside linebackers is the strongest pass-rusher on the team the 8-3 allows the defense to send him flying off the edge, potentially unlooked for, or stunting into an interior gap where the OL is deemed to be weak.
Attacking the spread offense
The natural response of many defensive coaches against the spread is to recruit speed and find ways to play sound defense while hoping for the offense to shoot itself in the foot or turn the ball over at some point along the way to the end zone.
The more skilled spread attacks are totally unafraid of this approach since it allows them to zero in on weaknesses, put defenders in conflict with the option, and do exactly what they practice every day to do. It's becoming less and less of a good bet that college players will be unable to sustain drives if you hole up and dare them to come after you unless you are recruiting NFL athletes at most positions.
The 8-3 is going to find more and more usage from defensive coaches that prefer to attack the offense, dictate what they're able to do, and try to see if college players can handle facing a defense that forces them to think through both their own options as well as those of the defensive coordinator.