Identifying Defensive Alignments in Football
For a quarterback, understanding what is happening on the defensive side of the ball is just as important as your throwing mechanics or footwork. The ability to process what you see quickly will allow you to understand what the defense is trying to do against you on every play. Since every defense has a weakness or hole, identifying what they are playing will allow you to execute and exploit its deficiencies.
Here are the three basic elements of a defense:
- Gap Alignment
- Box Count
- Coverage
Gap Alignment
The basics of identifying the defense lies in simply knowing how many defensive linemen are there and where are they lined up. What a young quarterback has to learn is what “technique” they are playing or what “shade” are they in. When offenses get more advanced, the alignment of these players becomes very important for the QB to understand. 
The first thing a QB needs to understand is gap control and where run play is designed to go. Is it an A-GAP run (Power) or a C-GAP run (Outside Zone)? Understanding the design of the play will allow you to use your knowledge of the shades and techniques to your advantage. Certain plays like power or zone are better suited to be run at a specific look. Your coach will say, run this play at the 3 technique, so, with our knowledge from the above chart, we will understand what coach is saying.
The next step of identifying the D-Line Technique is being able to quick understand what defense you are up against. As you can see in the picture below, there are 3 defensive linemen with a 0, 2, and 4 techniques. Seeing this should alert you that you’re facing a 3-4 defense — this means 3 DL and 4 LB.
In this picture, you will notice that there are 4 defensive linemen and, from left-to-right, it’s a 7, 3, 1, and 5 technique. This alignment allows you to know that you’re facing a 4-3 defense, or 4 DL and 3 LB
Box Count
The next thing a quarterback needs to identify is what the box count is. The tackle box can be simply explained as an imaginary line drawn from the outside shoulder of the left tackle four yards downfield and across to the outside shoulder of the right tackle.
The players inside the box are the defense’s primary run-stopping players. The reason we count the box is to see if we have an advantage or disadvantage in the running game. In the picture below, the offense has 7 players near the box that could be in the blocking scheme, while the defense also has 7. This means that the offense has the ability to block all of the defensive players and, in all likelihood, have the advantage.
The box count as a young QB is important to discuss after drives — so, as you come off the field, tell your coach of any advantages in the box and, thusly, make adjustments. As you become more advanced, there will be a “check” in your offense that allows you change the play to run when you have an advantage.
Coverage
The final piece to the puzzle is what coverage is the defense playing. This is how they are planning on defending the pass and where the extra run-support player can come from. Identifying the coverage is based on the both free and strong safety’s positions in the secondary. The possible coverages you could face are cover 0, 1, 2, 3, 4.
Final Assessment
Being able to understand and identify these three parts of the defense will allow a QB to evolve their game immensely. It will give them more confidence on game day knowing what the defense is trying to do to stop them, allowing them to exploit the weaknesses of every opposing side.
Look at the picture below and identify the defense being played and where the best place to attack it is.
(Answer: 4-3, Cover 2 — an offense should be able to run the ball, 6-on-6 blocking, to the void left between the 1 and 5 techniques.)
