When a commentator says an offence is in 11 personnel, they are not counting 11 players. Every legal offensive formation already has 11 players. The label tells you the skill-position mix.
The code
The first digit is running backs. The second digit is tight ends. Because there must be five eligible skill-position players alongside the quarterback and five offensive linemen, the number of wide receivers can be worked out from what remains.
| Package | RB | TE | WR | Common description |
|---|---|---|---|---|
| 11 personnel | 1 | 1 | 3 | Modern NFL staple |
| 12 personnel | 1 | 2 | 2 | Balanced run/pass flexibility |
| 21 personnel | 2 | 1 | 2 | Traditional fullback package |
| 22 personnel | 2 | 2 | 1 | Heavy / short yardage |
| 10 personnel | 1 | 0 | 4 | Spread passing package |
| 13 personnel | 1 | 3 | 1 | Heavy formation with play-action potential |
Why does personnel matter?
Because the defence usually reacts to it. If the offence sends three wide receivers onto the field in 11 personnel, the defence may answer with nickel. If the offence uses two or three tight ends, the defence may keep more linebackers or larger run defenders on the field.
Why coaches love 12 personnel
Two tight ends can create ambiguity. The offence can line up in a heavy run formation, then split one tight end wide and suddenly look more like a passing formation without substituting.
If the defence responds with bigger personnel, the offence can throw. If the defence responds with smaller defensive backs, the offence can run at them.
A viewing shortcut
Before the snap, count running backs and tight ends rather than trying to memorise the entire formation. You will quickly recognise why the defence has chosen its own personnel package.
Remember it this way: 12 personnel = 1 running back + 2 tight ends. The remaining two skill players are wide receivers. Once that clicks, the whole numbering system becomes easy.