Playbooks

FB Dive Weak lines up out of the Split T formation in the Tight set with a 32 personnel grouping, putting the fullback directly behind the QB with the HB offset to the weak side. At the snap the fullback takes the handoff and hits the weak side gap behind the center and weak guard, running downhill through the A gap opposite the tight end. This is a pure gap run play with no play-action or RPO element, designed to attack the interior of the defense before the front can flow and fill, with the primary read being the weak side A gap first and a bounce to the B gap if the nose or defensive tackle penetrates.
Key the nose tackle and weak side defensive tackle alignment pre-snap: if they are shaded into the weak side A and B gaps, this play is nearly dead on arrival and should not be called. Watch for the weak side linebacker creeping downhill before the snap, which signals a run blitz or gap exchange designed to blow up the fullback dive at the mesh point. Post-snap, track whether the mike linebacker flows fast to the play side or hesitates reading the fullback, since fast flow linebackers are the biggest threat to string this run out for a loss. This play struggles against odd fronts with a true nose over center and any defense that gaps out its defensive line pre-snap, since there is no lead blocker to clean up penetration. It beats light boxes and defenses that are backed off in coverage shells expecting pass, since the fullback can get two or three yards before the second level defenders even trigger downhill.
Run this out of base personnel looks when the defense shows a light box with six or fewer defenders in the tackle box, since the fullback dive lives on numbers advantage at the point of attack.
Check the linebacker depth pre-snap: if the mike and weak side linebacker are sitting back off the ball reading run fits, audible into HB Lead or Mtn HB Lead Dive instead since the fullback dive needs quick linebacker flow to hit the crease.
Use this play on early downs in short yardage or two point conversion situations where a quick, decisive one or two yard gain moves the chains or extends a drive.
Pair FB Dive Weak with PA Boot or Fk FB Toss Boot Lt later in a series so the defense has to respect the fullback dive action and bites on the play fake, opening up the boot passing lanes.
Avoid calling this against stacked fronts with a shaded nose tackle over the center, since the weak side A gap gets clogged immediately and there is no cutback design built into the blocking scheme.