Let's Learn Football!! Episode #2

As I have been creating and reading some Fanposts it occurred to me that some of the verbiage and explanations being used might be confusing for some readers. Having knowledge about something will automatically enhance your appreciation for it. Assuming that you are reading this on an NFL team blog, you are obviously interested in football. What better way to enhance your passion for it than learning it on a more in-depth level? While I am not as versed as professional coaches, hopefully I can use my knowledge as a former college player to explain the game in more detail. For this series I will NOT begin breaking down the game from the most basic concepts and rules, but I will start from an average fan's perspective and work into more complex topics. If there is any topic that you feel is interesting, please leave it in the comments and I will try to address it on a future post. I hope you enjoy.

The previous post in this series can be found here.



Personnel describes which type of players are being used for a certain play on both offense and defense. Depending on which type of personnel grouping takes the field for the offense for a particular play, the defense will adjust their personnel to try and matchup best with the offense.

Offensive Personnel:

Since there are 5 linemen and a QB in on every play, offensive groupings are given a 2 digit number to determine which 5 skill positions (WR,TE, RB) take the field for a particular play. The first digit describes the amount of RB in on that play and the second digit describes the amount of TE in on the play. Add those digits together. If the total is less than 5, you then add as many WR as you need to get to 5 players.

For Example: If the offense came out in "21" personnel, the "2" in 21 would represent 2 RB, the "1" would represent 1 TE. Add (2) RB and (1) TE and you have 3 players, so you would need (2) WR to make up 5 players completing the skill positions for that grouping.

Teams might have specific names for personnel groupings like: Heavy, Speed, Trio, Dual etc.., but those are just nicknames decided on by the team to quickly call out a specific # grouping (11,12,21,22 etc..)

To break it down visually the chart below has the grouping # highlighted in yellow with the positions required to complete that grouping.

A Goal Line offense will consist of adding extra OL and TE to be able to create a strong push toward the end zone or in a short yardage situation using your bigger, stronger players and does not go by a grouping #, but will just be referred to as Goal Line. Within this Goal Line package teams can have sub groupings like "Goal Line Light" which would could be 7 OL with 1 RB and 2 WR, but these can vary individually by teams and are not considered uniform personnel groupings. However, teams can still opt to use any variation of personnel in this area of the field. Quite often, teams will still utilize 3 and 4 WR sets to spread the defense out to make more room across the field to operate or to create mismatches in personnel against the defense.

Defensive Personnel/Fronts:

While the offense assigns numbers to call out personnel groupings, the defense uses names to get the correct personnel on the field.

Defenses also have multiple groupings to get to, but first we must understand the basic formations. Defensive formations/schemes are named after amount of DL and LB on the field at one time. A basic defense has 4 DB on the field (2CB & 2S). The other 7 positions made up of your DL and LB are known as the Front 7. How you deploy your Front 7 determines what your base defense is. If you have 4 DL and 3 LB you are in a base 4-3. If you choose to play 3 DL and 4 LB you are in a base 3-4. In the past, most teams tailored their rosters to play one of these formations exclusively as their foundation/base defense. Teams can also use different variations like a 5-2 or 4-4 on lower levels of football where offenses are predominantly more run heavy. But with the rules changes and the explosion of the passing offense in the NFL today, teams tend to be more versatile in roster construction and like to vary between fronts to matchup better with the offense. This tends to teams adding more DB on the field and removing front 7 personnel. These are known as sub packages. In fact, in the league today, some teams play more snaps per game in sub packages and create exclusive defensive game plans with them that they can be viewed as a base defense.

There can be many variations of the sub package defense, but the basic concept has 3 main formations/groupings. The sub packages are named after the amount of DB on the field. A Nickel Defense has 5 DB on the field at one time (hence the nickel name). A Dime defense has 6 DB on the field, and the Quarter defense can be 7 or more.

As with the offense, another sub package is the Goal Line defense. This is where a team will remove smaller bodied players like CB or S and deploy the bigger players such as DL and LB to try and be stout at the line of scrimmage to prevent against short runs to the end zone or in short yardage situations. But as with any defensive formation, it is dictated by the offensive personnel on the field, so any defensive grouping can be deployed on any part of the field at any time.

Fun Fact: By rule, if the offense makes substitutions, it must allow the defense to make substitutions also. In order for the defense to match up with the proper offensive personnel on the fly, there is usually a defensive assistant whose only job on gameday is watching which players enter the field for the offense and letting the defensive coordinator know by calling out the grouping (11,12,21 etc..). This is vital so that the DC can adjust his defense to get the proper personnel in the game. Considering the 40 second play clock, this has to be done in seconds after each play that the offense substitutes.

Now that we have a brief understanding of some general offensive and defensive personnel, formations, and packages, we can understand the chart below detailing the general rule of what defensive groupings counter or match up with certain offensive groupings. As always, this chart is just a general baseline as coaches can choose any defensive grouping, whether due to matchup, injury, effectiveness or otherwise that they feel will give them the best chance at success against their opponent's offense.

This is why players in the mold of Travis Kelce, Tony Gonzalez, Darren Waller are matchup nightmares for the defense. By position they are big bodied TE and should be able to overpower smaller DB when run blocking, but are to fast and athletic to be covered by LB on pass routes. For example: If the offense came out in "21" personnel with Tony Gonzalez at TE, the traditional defensive counter would be base defense, but when they get to the LOS, Gonzalez is not positioned in line next to the OT but flexed into the slot. So now the offense is really in a "20" personnel look which should be countered with an extra DB by a nickel defense, but since they are using the base defense, he is now covered by a LB. But if you play nickel, they can line up with Gonzalez in line where he can overpower the extra DB while run blocking. Hence the matchup problem these type of players present for the defense and why having versatile, athletic defenders are becoming more of a premium.

Within the concepts of these base defenses and sub packages there are more complex fronts, personnel and coverages that can be associated with them. These will be covered more in depth in later posts about each individual base defense and sub package.

As we build on the topics from previous posts, the explanations and concepts will become more complex. If there is anything covered here or in another post that needs more clarification let me know in the comments and as always, I will do my best to answer.

This FanPost was written by a member of the Bolts From The Blue community and does not necessarily reflect the views of the Bolts From The Blue editors or SB Nation.