What are Gaps in Football?

During a football broadcast, you hear announcers repeatedly using words and phrases such as “gaps,” “shaded,” and “3-technique.” You likely understand these football fundamentals far better than you realize, as you have observed their applications hundreds if not thousands of times.

You just need to be able to assign names to what you see. 

For example, “gaps” are the spaces between the offensive lineman. 

In this article, I explore gaps in further detail, how defenses plug these gaps, and defensive line assignments and techniques.

Key Takeaways

• Gaps are the spaces between the offensive linemen, and we differentiate them with letters.
• For example, between the center and the guard is the A-Gap, between the guard and tackle is the B-Gap, between the tackle and tight end is the C-Gap, and outside the tight end is the D-gap.
• Techniques inform defensive linemen where to line up to best clog their assigned gaps and disrupt the offense’s running attack.
• Techniques use a numerical system to specify the position of a defensive lineman relative to the offensive lineman from which he is across. 

What Are Gaps Exactly?

Gaps are the spaces between the offensive linemen, and we label them with letters.

For example, between the center and the guard is the A-Gap, between the guard and tackle is the B-Gap, between the tackle and tight end is the C-Gap, and outside the tight end is the D-gap.

Every gap possesses a duplicate; for example, there are two “A’” gaps, one on each side of the center. There are also two “B” gaps, one between the guard and tackle on the left side of the formation and one between the guard and tackle on the right side. This also holds for the “C” and “D” gaps.

Note that there aren’t offensive B-gaps or defensive B-gaps; there is just the B-gap. [1]  

The offense wants to protect these gaps and use them as lanes the running back can run through. [2]

The below video addresses the gaps in the offensive line and demonstrates how Dallas Cowboys running back, Ezekiel Elliot, runs through each of them:

The defense needs to close these gaps, preventing the offense from running the ball. 

Read more: 11 FOOTBALL OFFENSIVE POSITIONS EXPLAINED 2022

Defensive Line Gap Responsibilities

Every defensive lineman will have a particular pre-snap responsibility as to which gap he is responsible for filling. 

For example, say you are a defensive lineman who lines up in the A-gap prior to the snap. Your job on this run play is to clog that gap and prevent the running back from running through it.

Unlike offensive linemen, defensive linemen have options when lining up at the line of scrimmage.

Do they line up directly in front of the offensive linemen or shade toward one of the gaps?

This is where “technique” comes into play. [3]

Techniques

Techniques use a numerical system to specify the position of a defensive lineman relative to the offensive lineman from which he is across. [4]

For this numerical system to be practical, it must correspond to a constant alignment, for example, the offensive line.

The offensive line almost invariably lines up in the same way. You’ll have your left tackle, left guard, center, right guard, and right tackle. 

As a result, the numbers used to designate techniques and position defensive linemen properly are always relative to the positions of offensive linemen. [5]

How does the Numerical Technique System Work?

We’ve all heard a football announcer comment, “He’s a 3-technique defensive tackle.” This is where the term comes from.

In the above diagram, the yellow numbers at the top indicate the defensive lineman’s technique.

The even numbers 0, 2, and 4 designate head-up alignments – when the defensive lineman is directly in front of the offensive lineman. For example, a 0-technique defensive tackle aligns himself directly over the center, while a 2-technique defensive tackle aligns himself over the guard. [6]

The even numbers with an “i,” for example, 2i and 4i, indicate the defensive lineman should be opposite the inside shoulder of the offensive lineman. For example, a 4i-technique defensive end plays between the guard and the tackle in the B-gap. [7]

The odd numbers 1, 3, and 5 indicate the defensive lineman is opposite the outside shoulder of the offensive lineman, moving into the gap on the outside of the offensive player’s shoulder. For example, a 1-technique defensive tackle plays in the A-gap gap between the center and the guard. [8]

Note “inside” refers to the shoulder closer to the center, while “outside” refers to the shoulder farther from the center. [9]

Furthermore, we refer to any defensive lineman aligned to the inside or outside shoulder of an offensive lineman as “shaded.”

Now we know that the aforementioned announcer refers to a defensive tackle in the B-gap, shaded to the guard’s an outside shoulder.

Examples of Techniques:

These examples show that defensive linemen are not restricted to one technique. They often shift techniques. 

Example 1:

In the above photo of the Pittsburgh Steelers’ defensive alignment, you can see nose tackle Isaiah Buggs is head up over center, directly over the center’s helmet, and is a 0-technique. 

Defensive ends Chris Wormley and Cam Heyward line up in the B-gaps, across from the inside shoulder of the offensive tackles. They are 4i-techniques. [10]

Example 2:

In the second photo of the Pittsburgh Steelers’ defensive alignment, you can see nose tackle Isaiah Buggs is no longer a 0-technique, head up over center. Instead, he is now a 1-technique nose tackle, lined up in the A-gap, across from the outside shoulder of the center. 

Defensive end Chris Wormley is still lined up in the B-gap, across from the inside shoulder of the offensive tackle, and remains a 4i-technique. 

Lastly, defensive end Cam Heyward is no longer a 4i-technique but has shifted to the outside shoulder of the offensive tackle into the C-gap and is a 5-technique. [11]

Example 3:

In the third photo of the Pittsburgh Steelers’ defensive alignment, there are only two defensive linemen: Chris Wormley and Cam Heyward. 

Wormley lines up across from the inside shoulder of the offensive guard, placing him in the A-gap, and is a 2i-technique. 

Lastly, defensive end Cam Heyward is no longer a 5-technique but has shifted to the outside shoulder of the offensive guard into the B-gap and is a 3-technique. (I believe that Heyward is closer to the tackle’s inside shoulder and is a 4i-technique, but this is an inexact science). [12]

Is That All?

Of course, that’s not all! However, I hope I have helped you understand some football fundamentals, providing you with a more enjoyable football experience. 

This article is only the beginning, and I encourage all to stay tuned as I continue to break down and simplify this complex game. 

References:

1. https://www.bannersociety.com/2020/4/21/21083789/football-gaps-holes-numbers-explain
2. Football Breakdown: Gaps and Running Lanes
3. https://www.thephinsider.com/2014/3/7/5482102/football-101-defensive-line-gap-techniques
4. https://www.cbsnews.com/chicago/news/durkins-football-101-gaps-techniques-alignments/
5. https://insidethestar.com/schemes-concepts-chapter-1-gaps-techniques/
6. https://www.thephinsider.com/2014/3/7/5482102/football-101-defensive-line-gap-techniques
7. https://www.thephinsider.com/2014/3/7/5482102/football-101-defensive-line-gap-techniques
8. https://www.thephinsider.com/2014/3/7/5482102/football-101-defensive-line-gap-techniques
9. https://www.cbsnews.com/chicago/news/durkins-football-101-gaps-techniques-alignments/
10. Football 101: Defensive Line Alignment & Explaining Gaps
11. Football 101: Defensive Line Alignment & Explaining Gaps
12. Football 101: Defensive Line Alignment & Explaining Gaps