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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.
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.