You see them throughout the league every week and they have been a nightmare for defenses to try to contain for a number of years. Now, defensive coordinators are getting creative in how they defend against stacked formations.
With the rise of the spread offense and mobile quarterbacks, stacked (or bunch) formations present an almost unique threat. More than any base formation, bunched sets can have four options built in as either individual play calls, as a pre-snap run-pass option (RPO) or post-snap RPO.
Defenses must be aware and ready to cover all four possibilities: a running back handoff, a quarterback option, a bubble-screen or a dropback pass.
Stopping any form of pass has been the most problematic for defenses. With receivers stacked, they are able to get a free release at the line of scrimmage without cornerbacks being able to press them and disrupt the timing of their route.
If corners attempt to play press-coverage by jamming the “point man” ( the receiver at the top of the stack) it creates a natural “rub” or “pick” for the receivers at the foot of the formation to get a free release, or sets up the chance for a big play on a bubble-screen.
Play zone or off-man coverage and a defense is giving all three receivers a free release by design and gifting yards on quick release throws.
The problem has plagued coordinators for a number of years, but like most thing in football, over time new approaches are designed to shutdown offensive innovation. Most coordinators have used two tactics to slow down stacked formations.
The first is utilizing zone-pressures: blitzing the quarterback — usually with corner blitzes — and dropping the rest of the secondary and linebackers into zone or pattern-match coverage.
Like any blitz or zone-pressure it is a boom-or-bust approach that is susceptible to giving up a big play, particularly if the ball is out quickly on bubble-screens.
The second and more effective approach has been to play a form of switch or “Banjo” coverage. Banjo coverage is a hybrid zone-man coverage that usually involves one cornerback playing press-coverage while the other cornerbacks play off-man coverage.
To combat the free release that the receivers at the foot of the stack get – regardless of whether it is a two-man or three-man stack – defenses will align a corner up over the point man, but let him release freely and have the corner closest to the line of scrimmage pick up the receiver with the furthest distance to travel to the line of scrimmage or who releases last – the guy most likely to receive the ball on any form of screen pass.
Watch the GIF below: Florida is a three-receiver stack, the “up back” — cornerback closest to the stacked formation — reads the release of the receivers and picks up the receiver who releases to the flat.
By virtue of lining up over the stacked formation the cornerback disrupts the release of the receiver at the head of the stack, then gets to flatten the receiver before he clears the line of scrimmage.
The cornerbacks and linebacker in off-man and zone coverage then read the release of the other receivers and convert to man-to-man coverage when they enter their zone.
It’s the same when defending two-man stacks. Below, the Georgia cornerback at the line of scrimmage is picking up the receiver at the foot of the stack, and the cornerback in off-coverage picks up the receiver at the head of the stack.
The cornerback pressed up at the line of scrimmage automatically disrupts the route of the point man by being in his face. Both corners pick up the man with the shortest distance between them with the up back letting the first receiver release and picking up the second receiver.
Think of it like a switch in basketball: defenders take the shortest distance possible to defend an offensive player in man-to-man defense and switch assignments to limit crossing paths with each other and creating a ‘pick’ play.
Although the tactic has been effective at reducing the impact of bunched and stacked formations when defending against the passing game — particularly in short yardage situations — the benefits to this formation overall are impossible to eliminate. It still involves the offense setting the tone for the defense, controlling pre-snap looks, and forcing defensive communication, which, by definition, can lead to miscommunication and blown assignments.
But, thus far, mixing between zone-blitzes and Banjo coverage has been the most creative way to defend against stacks. It’s also another example of how defenses continue to evolve as they deal with the modern threats of run-pass option plays and quarterbacks who are threat with their arm and legs.