clock menu more-arrow no yes

Filed under:

The science of the bubble screen

New, 1 comment

Perhaps the most poorly understood play in college football.

NCAA Football: Texas Christian at Arkansas Joey Johnson-USA TODAY Sports

The bubble screen used to be one of the most unpopular play calls in college football. “What’s the use of a dink and dunk lateral pass that gets maybe five yards? Throw it down the field!” was a popular response from fans and commentators that would also applaud five yard runs as an act of indomitable will.

Eventually spread teams started to get very efficient with the bubble screen, using it to eviscerate teams that wanted to load the box to stop their run games and snatching up yardage in chunks while flipping the ball out to star athletes in space. Watching a team march down the field throwing quick lateral screens was quickly felt as akin to watching a team maintaining a drive while running the ball off tackle.

Nowadays, when everyone is in the spread at least as often as not, it’s common for fans and commentators to offer the following lament when their RB is struggling to find room to run, “we gotta throw more bubble screens!” That’s a positive development really, as it illustrates a popular understanding that the bubble screen is essentially an option pitch and a component of the run game. Now to take it another level, here’s how it works against the various ways of defending it.

The execution of the play

The success of a bubble screen primarily comes down to three factors. First, the initial read by the QB or play-caller on the leverage of the defense against the play. If the offense misreads the play and thinks the target of the screen will catch the ball in space behind a block and then he doesn’t...it can look pretty ugly.

In order to clear things up for the QB, or to even get the defense to concede any space to throw the bubble screen at all, teams will often throw it these days by motioning the target of the bubble out wide just before the snap.

The next key is the block by the outside receiver on the cornerback. Ideally he’s turning the CB’s shoulder and hooking him inside so the receiver can get outside.

It’s when the WR can work outside of the perimeter block at the line of scrimmage that the play tends to do its real damage.

Conversely, the corner or nickel playing the block wants to force it back inside to the pursuit of the safeties and linebackers. Here’s an example where TCU uses motion to try and get the leverage needed to throw the play:

West Virginia “spur” safety Kyzir White (brother to fellow West Virginia stars Kevin and Ka’Raun White) adjusts and beats the block to force the ball back inside. At 6-2, 215 White is good at playing perimeter blocks physically for the Mountaineers. When you get good force play like that on the edge the defense has a chance to constrict the space and an outcome like this, where the middle linebacker is making a big hit after a one yard gain, becomes attainable.

Finally there’s the timing and placement of the ball by the QB.

Stanford plays the block by Oregon well here but the Ducks left yardage on the field when their WR had to use his first steps after catching the ball to find the ground and his balance. Additionally, the longer you ask a receiver to sustain a block, the worse chances you have of winning the edge. Particularly before pursuit arrives.

The schematics of defending the bubble

There are a few different tactics defenses use to try and defend the bubble screen, each of which requires varying degrees of difficulty to execute. Perhaps the most challenging is the Spartan way, in which the flat defender over the slot receiver is crashing to the edge to outnumber the run game and the corner and deep safety have to stop the play without help.

That hasn’t tended to go terribly well for Michigan State over the years and is a factor in their struggles to stop spread passing teams. It can work though when the corner forces the ball back inside and lines up the receiver into a narrow window being filled by a hard running safety.

The middle of the road strategy is to have the nickel defender over the slot try to pause and wait so that he can make a hopefully still timely arrival against either the perimeter run or the screen pass.

As you can see, a timely and physical play on the block is still the biggest key, if Texas had that here this is probably a minor or even non-gain. A really athletic and fast-playing nickel makes this a pretty nasty strategy since he can make both runs and perimeter passes a very difficult way to stay ahead of the chains by arriving to make stops within a few yards of the line of scrimmage.

Finally there’s the cover down, which is how single-high safety defenses tend to deal with the bubble screen but you also see it from two-high teams these days. The cover down is simply the defender over the slot receiver mirroring his movements at the snap rather than reading backfield action. If the nickel or outside linebacker is running with the slot defender as he steps into the quick route then he can’t really be blocked. You’re just throwing a pass behind the line of scrimmage to a covered player.

For single-high teams dealing with the bubble screen is a non-issue since they have underneath defenders covering down on all of the likely targets and (hopefully) guaranteeing a fantastically negative result if the offense tries to throw the quick pass. For two-high teams there’s a real choice to be made about whether or not to deny the bubble screen by playing it aggressively with the nickel and stopping the run without the assistance of that position or else keeping the nickel involved against the run to some degree and relying on the corner’s play against the block to stop the run.

Since the bubble screen is intended as a way to punish teams for outnumbering the run by attacking off the perimeter, dominant play by the corner against the outside receiver’s block is the most useful play a defense can receive in stopping these tactics. Now you know what to look for the next time the bubble screen shows up on your TV screen.