also: dive read · No. 1 key · mesh key · first read
The unblocked interior defender in an option play whose post-snap reaction tells the quarterback whether to hand off to the dive back or pull the ball.
The dive key (often designated as No. 1 in option counting systems) is the first unblocked defender the quarterback reads in an option scheme.
After the snap, the quarterback rides the running back through the mesh point while watching the dive key:
In traditional Veer and Zone Read schemes, the dive key is usually the defensive end on the edge of the front. In Midline schemes, the dive key moves inside to an interior defensive tackle (a 1-technique or 3-technique).
No. 1 key, dive readpitch key, read defenderIn triple option systems, the dive key is the first read in the sequence, followed immediately by the pitch key on the perimeter.