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Run Fits in Football: The Complete Guide

Posted by Tyler Manes on

With the modern spread, RPOs and popularization of Air Raid concepts most think that the back end of defense has become more multiple to combat these popular concepts. And although that may be true with many defenses going to “match coverage” and more “middle of the field open” coverages, there is one consequence of this most people overlook, run fits. 

With dozens of different approaches to fit all the different runs, its vital for coaches to be able to communicate to one another what they do to be successful. This is where “coach speak” is important and can lead to growth during the offseason, but in the same vein its important to understand that coach speak is just that.

Coaches must take terms like “front spacing” and “gapped out fits” and translate that into easily executable scheme for players. While at the same time understand that run fits are extremely varied based on talent and philosophy, there is no one size fits all. The valuable part is that concepts and tools are grasped so they can be put into your own tool box for success.

Types of Run Fits:

The term “spacing” has many uses in modern football today. To offensive coaches spacing most likely means they are talking about receiver splits in relation to each other or the core formation. Whereas “spacing” for a defensive coach is many times going to talking about the run fit. Although every team has different mechanics on how to fit the run, there are two core influences that each run fit stems from. First influence is going to be the type of front, either “even spacing” or “odd spacing”. And second is going to be coverage played behind the run fit. 

The crucial part to understand about front “spacing” is that it does not matter what front the defense starts in, only what front they end up in post snap.

In the simplest term there is only one detail that differentiates a front from Odd and Even, and that is where is the run fit “bubble” or open gap. In even spacing the open gap is the B gap.

In traditional Over front defense the “bubble” is away from the TE. This is important to offenses because the “bubble” is where they have the best leverage to run the football.Over Front B Gap Bubble

In odd spacing the open gaps move from the B gap, to the C gaps (think traditional Tite/Mint front defense). Another way to easily tell the difference is if there is a head up nose or a shaded nose. 

Tite Mint Front C Gap Bubble

The next part of “spacing” is going to be the terms 7, 8 or 9 man spacing. This has to do with the coverage played behind the run fit and this is also where a coach can fall down the rabbit hole. The easiest way to explain it is that the numbers that come before spacing indicate how many people are in the “box” or “run fit” vs 12/21 personnel. Now as these eligible receivers move outside the core to split WR’s, the number of defenders in the boxes also moves with them. 

7-man Spacing

In 7 man spacing the defense is minus 1 defender in the box vs the run. Many people call the defense in 7 man spacing “out-gapped” or that they are in a “light box”. The coverage can change, but in the simplest terms the coverage is going to be some variation of “middle of the field open” coverage whether that be 2 man, match quarters or another variation. The overhangs are going to be “out of the fit” and are going to be pass first players, because of this the defense is down one defender in the box and there is one open gap. 

To combat this there are many tools that a defense can carry in 7 man spacing to still “make the fit right”. A defense can 2 gap a defensive lineman to account for the extra gap. They can also “roll the ball off the shelf” to their widened overhangs by playing defenders in the B gaps (tite front) or they can do this post snap with a stunt or slant (Jimmy/Pony). Almost all of these tools listed are at the 1st level, likewise there are common tools at the 2nd level that are associated with each spacing.

In 7 man spacing versus zone scheme it is common to see teams play “stack track and fallback” with the inside linebackers. This is where the linebackers are not vertically plugging gaps, but instead “stacking” targets and “tracking/fallingback” with the ball carrier. Versus gap scheme with a puller it is common to see defenses playing “spill-overlap” with the inside linebackers. The playside linebacker will “spill” the kickout and the backside linebacker will “overlap” the kickout.

Both of these run fit concepts are used commonly in 7 man spacing because it allows the defense to fit the run without having even numbers in the box. This is not always true as run fits are heavily customizable to fit a teams philosophy and players.

7 Man Spacing vs Zone Scheme

Run Fits - 7 Man Spacing vs Zone

In this diagram the defense is playing “stack-track-fallback” based off of the path of the ball. The inside linebackers can stack the open gap or block depending on how the fit is being taught and then mirroring the ball.

7 Man Spacing vs Power

Run Fits - 7 Man Spacing vs Power

In 7 man spacing defenses commonly play “spill-overlap” vs gap scheme as seen in this diagram. The playside five technique will spill the first kickout, the playside linebacker will spill (some people call this technique splatter) the 2nd puller (outside the first kick and inside the second kick, and the backside linebacker will overlap or be the outside piece of the fit. This allows the defense to fit gap scheme with only 2 defenders at the second level.

8-man Spacing

In 8 man spacing the defense is called “gapped-out” as they have 1 extra box defender compared to 7 man spacing and have an equal number of defenders in the box compared to the offense. The most common coverage family seen in 8 man spacing is going to be “middle of the field closed” coverage whether that be cover 1 or cover 3. 8 Man spacing is going to be “one gap” run fits, in that each defender is responsible for one gap. 1st level defenders are typically more of an attack philosophy rather then 2 gapping with emphasis on block reaction like in 7 man spacing.

The 2nd level once again has different tools typically used in 8 man spacing. The first tool would be “indicator fitting” in that the 2nd level defenders are going to be fitting one gap off of the Tight Ends movement. If the TE is across the formation like in split zone, then the 2nd level defenders will bump over post snap with the Tight End. Versus gap scheme defenses commonly play “lever-spill-lever”. In this the playside defender will be a “box” player or fit outside or the kickout, the middle defender will spill the 2nd puller and the backside defender can tempo the ball carrier. 

8 Man Spacing vs Zone

Run Fits - 8 Man Spacing vs Zone

In this run fit the 2nd level defenders are playing indicator fits based off the post snap movement of the TE in “Y-off”. With the Tight End across the formation the 2nd level defenders will fit one gap over to right and can play vertical in their gaps as they are “gapped out”. While this allows the defense to play vertical, a defense can will play stack track and fallback. The playside End can spill the kick from the Tight End and the playside 2nd level defender can fit outside in the D gap.

8 Man Spacing vs Power

Run Fits - 8 Man Spacing vs Power

In this diagram the defense is going to be playing “lever-spill-lever” since they now have an extra 2nd level defender compared to 7 man spacing. The playside five technique can spill the first kickout and the playside 2nd level defender can now box the ball (fit outside the kickout) back to the adjacent 2nd level defender. The backside piece of the run fit can now tempo the ball carrier. 

9-man Spacing

9 man spacing is commonly known to be called “maxed out” and have an extra defender in the box compared to the offense. 9 man spacing is also known as “blitz fits” as the defense is playing some form of cover 0. This run fit concept was made popular by Narduzzi’s form of quarters wherein the safeties are the “sky” force defenders are “in the fit”. People also called this coverage concept “4 mix” where the Safeties will have number two “up and out”. 

9 Man Spacing vs Zone Scheme

Run Fits - 9 Man Spacing vs Zone

In 9 man spacing the defense will have an extra defender in the box vs the offense. The first and second levels of the defense can play aggresive in their gaps since their is a defender for each gap. The end opposite the TE can remain in the C gap and spill the kickout, while the Nickel (overhang) can fit outside since they are “in the fit”. The Safety overtop the Tight End can track the Y across the formation post snap, or is free to play essentially “sky force” depending on what the defense does oppistite. 

9 Man Spacing vs Power

Run Fits - 9 Man Spacing vs Power

Versus gap scheme the run fit can look very much like 8 or 9 man spacing playside depending on the defenses philiopsophy. However in 9 man spacing there is going to be an extra defender in the box which would be the Nickel in the case of this diagram. 

3-4 Defense Run Fits

Now let's take a look at some run fits specifically from the 3-4 defense.

3-4 Defense: 7 Man Spacing vs Zone

3-4 Defense: 7 Man Spacing vs Zone

Now with all of the diagram before hand it is still important to remember that any spacing can still be “odd” or “even” front spacing. In this diagram the defense is in the tite/mint front and the 2nd level is playing A to C gap fits. The head up nose is “lag” which means hell play the backside A gap of any run. The inside linebackers will play stack track fallback and flow with the ball.

3-4 Defense: 7 Man Spacing vs Power

3-4 Defense Run Fits: 7 Man Spacing vs Power

Versus gap scheme in 7 man spacing the defense will still often play “spill-overlap” and with the overhang reduced with the tight end looks very much like an even front fit. 

3-4 Defense: 8 Man Spacing vs Zone

3-4 Defense: 8 Man Spacing vs Zone

Now continuing with a “Tite 4” presentation, the defense can very much look like they are in 7 man spacing with only 5 defenders in the box versus 4 open formations. However depending on how the overhangs are being taught, the defense can be in 7, 8 or 9 man spacing.

Often times the overhangs will be taught to “fill or freeze” based off the back. If the Running Back is to me, then I am the RPO player and out of the fit. If the Running Back is away from me then I am the “fill” player and I am in the run fit and can be aggressive. 

3-4 Defense: 8 Man Spacing vs Power

3-4 Defense Run Fits - 8 Man Spacing vs Power

Now that the defense is using one of the overhangs (could be a safety or OLB), in the run fit, this allows the defense to play “lever-spill-lever” based off the running backs location. 

3-4 Defense: 9 Man Spacing vs Zone

3-4 Defense Run Fits - 9 Man Spacing vs Zone

9 man spacing from an odd front can look very similar to 8 or 9 man spacing depending on how a defense wants to play. They have an extra run fit defender, so this does allow a defense to play "one gap". However unlike 8 man spacing they will have an extra hat from an overhang.

3-4 Defense: 9 Man Spacing vs Power

3-4 Defense Run Fits - 9 Man Spacing vs Power

The easiest way to see the Tite front (odd spacing) is as an already gap exchanged even front. With the 5 technique that typically gap exchanges, now already starting in the B gap. A defense can play either spill overlap or lever-spill-lever in 9 man spacing but will have an additional hat in the box. 

Want more? 

Check out the excellent video clinic Coach Manes put together on the Tite Front Defense.