The 3-4 vs the 4-3 Defense

“A&M is running a 3-4 scheme on defense that Oklahoma State isn’t used to” was the explanation given by the broadcasters as to why the Cowboys went scoreless for almost the entire first half of the Thursday night’s Texas A&M vs Oklahoma State game (2010).  While the 3-4 Defense is not currently the norm in college football (schemes come and go), it is becoming more popular these days as seven teams made the switch in 2010, including Texas Tech, who the Cowboys faced two weeks later.  Luckily for Oklahoma State’s offense, they familiarized themselves rather quickly and made second half adjustments, which led to 21 unanswered points and ultimately a win.

In addition to Texas A&M and Texas Tech, Georgia, Georgia Tech, Houston, Notre Dame and Stanford all made the switch to the 3-4 Defense in  2010.  Combining that with the already established 3-4 Defenses run by Alabama, Air Force, Army, Navy, BYU, California and SMU, there were a total of 14 FBS teams who used 3 down Linemen and 4 Linebackers in 2010.

But what is the 3-4 Defense and how does it compare to the more popular 4-3 Defense?  As its name implies, it is a defensive formation that puts three men on the defensive line and four men behind them as linebackers.  The defensive linemen are often referred to as down linemen, or the ones with their hands in the dirt, and they are directly at the line of scrimmage.   The linebackers stand behind them and have more options in terms of positioning as they can stay back or even move up to the line of scrimmage.

The differences between the 3-4 and the 4-3 mostly concern the personnel and their responsibilities.  In the 4-3, the linemen are responsible for putting pressure on the quarterback and specifically the defensive ends will have the majority of sacks in this scheme. The linebackers stop the run and drop back into pass coverage (although they will also join in adding pressure on the quarterback in blitz plays).

In the 3-4 the linebackers are responsible for pressuring the quarterback and specifically the outside linebackers are the primary pass rushers. Any of the four linebackers will rush the quarterback on a given play, but those not putting pressure on the quarterback will need to stop the run and be speedy enough to drop back into coverage, depending on what the play calls for.

In the 4-3 the interior linemen (the defensive tackles) need to be big enough to take on multiple blockers, but because of their pass rushing duties they shouldn’t be so big that that they can’t fluidly move through the offensive linemen to the quarterback.

In the 3-4 the nose tackle needs to be even bigger than the defensive tackles in the 4-3, because he is the only defensive tackle and he will always be taking on multiple blockers with one less player on the line to assist him.  Finding the right nose tackle is one of the most challenging aspects of this scheme.  Alabama’s defense was among the country’s best in 2008 and 2009 because nose tackle Terrence Cody was so hard to block (he is currently playing in the NFL).  Because their main responsibility is to take on blocks with 2-Gap assignments (defending the space on both sides of him), the linemen won’t produce the impressive stats they might get playing in a 4-3.  Their job is to free up the linebackers to make plays.

The 3-4 gives you versatility, creates confusion and makes it harder for offenses to predict where the pressure is coming from.  This unpredictability is one of the biggest advantages of the 3-4 scheme as it hinders offenses who run the OPTION and who need to react quickly based on what they see from the defense in order to determine which option to use. Any of the four linebackers can blitz on a given play, or one of the outside linebackers can move to the line of scrimmage as a stand-up defensive end.

According to Al Groh (former Virginia head coach hired as Georgia Tech’s Defensive Coordinator in 2010 to switch them from the 4-3 to the 3-4): “I  like the flexibility of the defense…It provides different options to play against all of the spread formations that we are dealing with. When you have four players [linebackers] standing up and able to make adjustments, it gives you more options than if you only had three linebackers standing up.

Alabama head coach Nick Saban says “From a schematic standpoint, the 3-4 keeps quarterbacks, offensive linemen and offensive coordinators guessing before the snap. Any one of the four linebackers can rush the passer at any time.”