Personnel grouping
What it is
The two-digit shorthand for how many running backs and tight ends are on the field: first digit backs, second digit tight ends.
Why it matters
'11 personnel' is one back and one tight end, so three receivers; '12' is one back and two tight ends; '21' is two backs and one tight end. The second digit is the one that matters defensively, because tight ends decide whether the defense answers with a linebacker or a defensive back. Every substitution pattern in modern football is a conversation in this vocabulary — the offense declares personnel, the defense answers with its own, and the offense then chooses a formation that makes that answer wrong.
Also called
Programs call this 11 personnel, 12 personnel, 21 personnel, grouping or pers. The Coach answers to any of them.
See it on the field
Whether the defense brings a fourth defender over, and what it leaves alone if it does. The alignment comes from the engine’s own front resolver against real offensive splits, so it is a picture the simulator genuinely produces — not a diagram drawn to make a point.
Trips — three to a side, and the question it asksRelated
This entry is authored, not generated. It is one of 205 in the index that the AI-ssistant Coach retrieves from, and that Film Study tags clips against.