All-22: Is Chip Kelly's offense just simple math?

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All-22: Is Chip Kelly's offense just simple math?

Eagle Eye: Have the Eagles turned into a winner?

November 20, 2013, 12:30 pm
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On the Eagles’ second possession Sunday, a nine-yard run by LeSean McCoy was made possible by a formation designed to limit the number of defenders who could tackle the NFL’s leading rusher. (AP)

Chip Kelly likes to pretend he’s not really into math.

Whenever he’s asked about the mathematical advantages that play a significant role in his offensive blueprint, Kelly’s typically responds with, “I was told there would be no math,” a one-liner from the 1994 flick Reality Bites.

In reality, math is the backbone of Kelly’s read-option schemes in which the play call is often determined by the defensive alignment and where the most favorable numerical advantages are presented.

A great example from Sunday’s 24-16 win over the Redskins came on the Eagles’ second possession, a simple nine-yard run by LeSean McCoy made possible by a formation designed to limit the number of defenders who could tackle the NFL’s leading rusher.

Let’s take an All-22 look at the unconventional alignment that has right tackle Lane Johnson split wide alongside receiver Jason Avant, with DeSean Jackson two yards behind in a bubble-screen formation. At 305 pounds, the rookie Johnson should be an adequate lead blocker for the 178-pound Jackson.

The Redskins were ready for the formation. They had probably examined tape from the previous Sunday, when the Eagles came out in the exact same formation twice against the Packers.

Notice that the Packers defended the screen with two corners, creating a 3-on-2 matchup for the Eagles once Foles delivers the ball to Jackson on the right side.

Interestingly, on both of these formations against Green Bay, Johnson missed his block and Jackson gained minimal yards.

Nevertheless, the Redskins decided that they weren’t going to let the Eagles have favorable numbers on the outside. They flex an outside linebacker to the outside to even the matchup, leaving just five defenders at scrimmage to guard against the Eagles’ five-man offensive line and McCoy.

Simple math dictates that the Eagles have an extra-man advantage at scrimmage, so the play call changes from a screen to a handoff for McCoy. The Redskins try to even the score by bringing safety Brandon Meriweather into the box at the last minute, but the Eagles will take McCoy matched up against any defensive back 1 on 1 in the open field any time.

Here’s why:

Note the nice seal block by center Jason Kelce (62) on Redskins 300-pounder Jarvis Jenkins, making sure that McCoy has only Meriweather to beat.

Jenkins eventually shakes Kelce to wrap up McCoy, but only after a nine-yard gain.