In part 1, I covered the basic philosophy and advantages of running the football from the Shotgun. Part 2, we touched on how the dynamics of those advantages are increased if your QB is a threat to run. One way teams have adjusted to try and regain that advantage in the box is to have a force defender (usually a safety or CB) cheat in and defend the backside run from the slot position.
Once again, from Ross Fulton at Eleven Warriors:
As I have previously discussed, football is a game of arithmetic. The 'spread to run' helps an offense even the inherent arithmetic disadvantage by making the defense account for the quarterback as a run threat, allowing teams to run from the shotgun effectively. One way defenses attempt to 'cheat' in response to defend the zone is by sliding an an edge defender off the slot receiver into what Rich Rodriguez terms the 'gray area.' By bringing the highlighted defender closer to the box it assists in restoring the defense's numbers' advantage.
The bubble is therefore a a constraint upon a backside defender cheating against the zone read, which is itself a constraint upon the basic zone. We can thus work backwards and see how the spread-to-run offense developed. Teams wanted to find ways that they could establish an inside run game. But an offense must account for the backside defender, who is the quarterback's counterpart and thus unblocked. Coaches discovered that if they had the QB read that defender, suddenly that defender is constrained from crashing the front side run play, making it easier to run the base run play. If the defender continues to play the run, then the quarterback can simply pull and keep the football. In turn, a defense may respond by cheating their alley linebacker or nickel into the box. If that alley player can account for the quarterback, then the defensive end is again free to crash down upon the front side zone play. The bubble screen is a second level check upon the defense. It forces the defense to play straight up, providing the offense better numbers to run the base front side zone play. If the defense fails to do so, the QB simply turns and throws the bubble screen.
When you watch an Eagles game on TV, you'll often here an announcer talk about how Chip Kelly likes to "spread the field horizontally". This is what they mean, which is exactly what Ross describes above. Note the Eagles have 6 blockers in the run game. The Titans have 6 as well, but they also have a 7th force defender highlighted in red. As you can see already, he's going to be conflicted. If he plays the run, he's surrendering a 3 x 2 matchup on the bottom of the screen from the Eagles trips formation. If he stays out to cover the pass, he can't help in the run game, nor take responsibility for Sanchez on the keeper:
After the snap, you can see the force defender elects to cover the bubble screen on the outside.
Now Sanchez will read the edge defender who is the second-level linebacker and freezes him on the outside:
The Eagles now have 6 blockers on 5 box defenders and a terrific matchup for their inside zone running game. You can see from the shot above how Sanchez has frozen his read, and the Eagles set up nice combo and peel blocks on the inside zone.
One of the other advantages of this concept is that the inside zone read and the bubble screen can be packaged together in a packaged play, which essentially gives the QB three options 1) hand-off, 2) keep and run or 3) throw the bubble. Basically at the pre-snap if the defense loads up the box leaving a mismatch on the outside, the QB throws the bubble. However, if the team successfully spreads the defense like we showed in the first example, it will be a sign to run the football with an arithmetic advantage. Check out this example. Here at pre-snap, the Packers have only 6 in the box to defend the run. They have lined up over the bottom 2 WRs with help over the top. However, Micah Hyde is going to become the force defender and blitz from the slot. Sanchez, makes the right pre-snap read, but through the mesh point, given the cushion the receivers are getting he should probably throw the bubble.
Still, Hyde attacks wide and accounts for Sanchez. Since Hyde is going after Sanchez on the zone read, the Eagles have the 6 on 5 numbers advantage in the box, and you see the huge lane McCoy has to run:
However, as I pointed above, the beauty of the inside zone read/bubble packaged play is that the QB has three options. Unfortunately, without a mobile/fast/athletic QB the dynamics of this package are not as dangerous since Foles and Sanchez are not a huge threat to run. This allows defenses to overplay the bubble and the run game at times. A lot of people talk about how the lack of a mobility at the QB position impacts our running game. However, it also impacts the success of our bubble screen game, and for the most part, since Chip Kelly has arrived, the Eagles have not been able to take as much advantage of these stretch concepts as they would like. Here's why. Here the Rams line 4 defenders over the top of the Eagles trips formation on the top of the screen. In the run game there are 6 box defenders against 6 Eagles blockers. If you account for unblocked defender, the Eagles should have a 6 on 5 match-up. However, note the slot defender who will aggressively attack the backside off the snap:
Sanchez reads the blitzing slot defender. He basically pays no attention to Sanchez's read and crashes down on the run game:
You can see on the top the 3 Rams defenders all attack and protect against the bubble. Look at the huge space down the alley for the QB to keep and run:
Unfortunately, Sanchez handed off and McCoy got dropped for a minimal gain and was tackled by the force defender. Here, Sanchez, decision to not keep and run really impacts the Eagles chance of success on this play in a number of ways. The first is the most obvious one. If Sanchez keeps, he probably gets a nice gain on this play. However, the complete lack of respect that the force defender showed for Sanchez also creates less running room for McCoy. If the force defender even shows a little hesitation towards the running threat, McCoy probably has a lane on the backside to squeeze through.
Bottom line, the bigger the threat the QB is to run on this play, the more likely it is that a defense is going to overplay to protect from that backside run. The more they cheat, the more they open up the bubble screen and stretch concepts on the outside. As a result, if Foles, Sanchez, or Barkley are at the helm at QB in 2015, the less you can expect those bubble screens to have success on the outside.
One more for the road and we'll be back next week. While not a bubble screen, you can see the same type of stretch concept on this play. Here the Eagles line up Darren Sproles and Lesean McCoy in the backfield together. Before the snap, Sanchez motions Sproles wide and you can see the Cowboys safety will chase after him. Watch the impact stretching Sproles to the outside has on the defense:
The Eagles run the inside zone read and the unblocked edge defender crashes hard down on McCoy. Based on Sproles pre-snap motion and extension to the sidelines, he has absolutely cleared out the alley between the hash and the numbers:
But Sanchez chooses to hand off despite the edge defenders feet being almost perpendicular to the line of scrimmage: