A few weeks ago, we examined why Randall Cobb is "just" a slot receiver. We acknowledged that though he is probably the best slot receiver in the game of football, that inherently limits the amount of an impact he can have on the football. With that analysis came the assumption that Cobb struggles to get separation on deep routes and instead forces the Packers' coaching staff to play him in the slot because of those struggles and his ability to excel on shorter patterns.
Then Matt Harmon came along with his Reception Perception breakdown of Cobb today and made me rethink some of the arguments in that article. In fact, Harmon's analysis of Cobb's 2014 season suggest that he is not limited to just short timing routes (though he does excel at those); instead, he actually performed well out of the slot on deep routes as well.
Perhaps that $10 million per year isn't so absurd after all.
Let's take a look at Harmon's analysis and how it explains that Cobb is in fact a truly well-rounded slot receiver, who can stretch the field vertically as well as horizontally.
This part of Harmon's analysis shows how often each player runs the various types of routes. This is not necessarily a sign of what the player is capable of, but rather how he is used in the offense. Cobb's usage is quite different from that of Percy Harvin, who is Harmon's best example of the "slot/gadget" receiver and whom he analyzed earlier this year.
When comparing the data, a few things stand out: Harvin is used frequently on screen passes, where Cobb is not. Where Cobb drastically exceeds Harvin is on routes in the flat. These plays are designed to get Cobb open in space so Aaron Rodgers can get him the ball quickly and let him shake defenders. The concept is somewhat similar to screens, but the play designs will result in fewer blockers for the receiver and also requires a more accurate quarterback with better timing.
As far as the "timing and precision" routes (flats, posts, and slants) go, Cobb is used significantly more than Harvin by a rate of 46.9% to 33.7%. This is almost certainly related to the quarterback, but also likely has something to do with Cobb's ability to beat coverage on those routes, as we'll see below.
Ultimately, the Packers' coaching staff recognizes that Cobb's skill set is excellent on short routes and works well as a complement to Jordy Nelson. However, it would be a mistake to assume that Cobb cannot be a productive deep threat from the slot as well.
The success rate vs. coverage number measures how often the receiver was successful at getting open on each type of route. From Harmon's two articles, we have pulled both players' success rates in their sample games to show how effective each is. Here is where you can really see Cobb's versatility (and separation ability in general) come to light against Harvin:
The only routes where Harvin performs better than Cobb over the sampled games are curl and dig routes, which make up only 12-15% of the players' route trees. In all of the aforementioned timing route categories, Cobb exceeded 80% success rates; Harvin was almost at 80% in the flat (his least-frequent of these routes), and was between 50% and 63% on slants and posts.
In other words, Harvin didn't just have trouble producing in those routes because his quarterbacks' timing was poor; he simply wasn't getting open very much. This was even more evident on deep routes, on which he had no success rates better than 50%. Cobb, on the other hand, still posts success rates over 80% on corners and posts and over 60% on go (nine) routes. That is what surprised me the most - I had assumed that his success rates on deeper plays would be lower, and that this would be a major reason for his more frequent usage on shorter routes. Instead, Cobb gets open about as often when going deep as he does on short and intermediate patterns.
In our previous piece on Cobb, we made the argument that a major factor in favor of boundary receivers is that they tend to catch the ball farther downfield, and therefore are more valuable to an offense if all other things are equal. This remains true, and I still argue that Jordy Nelson is a more valuable piece to the Packers' offense than Randall Cobb.
However, Harmon's assessment suggests that Cobb actually excels at both short and deep routes, and that maybe, just maybe, it is because of scheme rather than skill after all. One critical piece to keep in mind, however, is that Cobb rarely runs these deep routes on the boundary, and thus the opposing cornerback does not have the benefit of the sideline to control the receiver's movement. Whether Cobb could maintain these success rates when split wide instead of lined up in the slot remains a question that will likely go unanswered for the next four years.
In any case, let's be happy that Cobb has returned to the Packers this season. With Jordy Nelson doing his thing deep and along the sideline, Cobb working his magic underneath with the occasional deep ball, and Davante Adams continuing to emerge on the other side, the Packers should have no trouble continuing to move the ball through the air in 2015 and beyond.