Deep third
What it is
Responsibility for one of the three deep segments of the field, with nothing allowed behind you.
Why it matters
A third is a landmark and a rule rather than a patch of grass: get to the outside shoulder of the widest vertical threat and stay on top of it. The defender playing a third should never be beaten deep, which means he plays every route as vertical until it declares otherwise and accepts the completion in front of him.
Also called
Programs call this third, deep outside third or top of the third. The Coach answers to any of them.
See it on the field
One safety in the middle, corners deep and outside, and an extra hat kept in the box. 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.
Cover 3 — three deep, four underRelated
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.