The foundation
Start here
Before the snap, a quarterback can count deep safeties, inspect corner leverage, locate pressure threats, and compare defenders with blockers. Those are clues, not guarantees. After the snap, rotation and the movement of a key defender confirm or change the read.
See it in context
- Two high safeties may suggest Cover 2 or quarters, so the quarterback reads how they respond to inside vertical routes.
- A nickel defender near the line may blitz, but the quarterback must also locate the defender who replaces him in coverage.