Heavy / Jumbo
Extra beef — dare them to stop the run.
Extra tight ends and linemen in the game, sometimes with no receivers at all. Heavy personnel forces the defense to match beef with beef and defend the run first — then play-action goes over the top of the safeties who bit.
What it does to the defense
Personnel and run fits: the defense has to substitute big and crowd the box. Safeties creep down to help — and the post is wide open behind them.
How each scheme uses it
Air Raid
Play-action pop passes to the tight ends; the shot play off heavy run action.
West Coast
Bootleg off heavy run action — the flat is completely empty.
Power Run (Gap)
The power-run home: duo, power, and counter downhill behind extra blockers.
Wide Zone
Heavy outside zone with every edge sealed by an extra body.
Spread Option
QB follow and load option — extra blockers for the keeper.
Vertical
Max-protect shot play: post and wheel off play-action with all day to throw.