Playbooks

HB Dive out of Strong I Z Close (21 personnel) is a downhill interior run that sends the halfback straight through the A gap behind the fullback lead block. The offensive line blocks straight ahead with double teams at the point of attack to seal the interior, and the fullback leads through the hole to pick up the first defender past the line of scrimmage. This is a pure run play with a one read progression: the HB reads the fullback's block and presses the A gap, bouncing outside only if the interior is completely clogged.
Watch linebacker depth before the snap since stacked linebackers sitting at five yards or closer can fill the A gap quickly and blow this up. A heavy box with eight or more defenders is the clearest sign to abandon this run and check to a play action shot play instead. Post snap, key the defensive tackles since a two gap read from a nose tackle can shed the double team and clog the dive lane. User controlled defenders flying downhill immediately at the snap often overpursue, which sets up the play action fakes from this same formation. Man coverage on the perimeter with no extra run support in the box is the ideal shell for this play since it isolates the fullback lead block one on one.
Run this on early downs when defenses are showing a light box of six or fewer to take advantage of numbers at the point of attack.
Check the defensive front pre-snap and audible away if you see a bear front or a 4-3 over shifted heavy toward the play side.
Use the fullback lead block as your primary key after the snap and trust the hole instead of bouncing it outside too early.
Pair this with PA Power O and PA Sail from the same Strong I Z Close set so the play action looks identical to the dive at the mesh point.
Mix in Counter Weak after a few successful dives to punish linebackers who start flowing hard downhill on run reads.