In my article on why the Cowboys should throw more often, I showed that Dallas has experienced far more success when passing the football often to start games as opposed to running in abundance. Passing with effectiveness wins games in the NFL, but I want to be clear that the running game serves important functions as well.
First, it keeps defenses off-balance. Efficient rushing can thwart the ability of defenders to immediately rush up the field. Second, rushing success is crucial in short-yardage situations. Throwing the football might get you down the field, but you need a powerful rushing attack inside the red zone.
The biggest reason a formidable ground attack can be valuable, however, is that it sets up big plays via the passing game. It's a whole lot easier for an offense to move downfield from a single deep pass than from a handful of successful runs, but those six- and eight-yard rushes can alter a defense's strategy and leave them susceptible to a deep passing play. Thus, although rushing frequently is unnecessary, running efficiently can have positive offensive effects that often manifest themselves in passing statistics.
The Cowboys have had a lot of success throwing the ball deep in recent years, peaking last season when Tony Romo led the NFL in completion percentage on passes of 20-plus yards. Amazingly, I recorded Romo as completing 32 of 58 passes that traveled 20 or more yards in the air, good for a 55.2 percent completion percentage. Romo's passer rating on these plays was a remarkable 125.4.
A lot of Romo's deep passing success in 2011 was likely the result of Laurent Robinson's presence, but I actually think rookie running back DeMarco Murray had an even larger impact. With a truly frightening ball-carrier in the backfield for the first time in a long time, Romo saw more Cover 1 and other defenses that called for one of the safeties to be in the box. The threat posed by Murray indirectly led to a lot of one-on-one coverage for Robinson.
Without Murray in town in 2009 or 2010, the Cowboys weren't quite as successful on deep targets. Romo's passer rating of 105.5 was still outstanding, but it doesn't nearly approach his 2011 standards. Actually, there's a pretty strong positive correlation between the overall team yards-per-carry and deep passing success; when the 'Boys turned in a gaudy 4.8 YPC in 2009, Romo's passer rating on deep throws was almost seven points higher than in the subsequent season when the offense averaged only 3.9 YPC in the games Romo played.
Despite the success Romo & Co. have seen on deep passes, the offense hasn't attempted many of them. Below, you can see how Romo's deep pass percentage stacks up with the league average, per Pro Football Focus.
The Cowboys have tallied a lower deep pass percentage than the rest of the league in each of the last three seasons. Romo has ranked 37th, 26th, and 18th in deep pass percentage during that span.
So the big question is why aren't the Cowboys throwing more deep passes? The most obvious answer is offensive line struggles. Things are looking up for the big guys up front, but the Cowboys' offensive line hasn't exactly been elite of late. Deep passes require ample protection, and that's something Jason Garrett might have believed was hard to come by.
Secondly, the 'Boys might not actually be quite as successful on deep passes as the numbers suggest. With a low deep pass percentage, chances are Romo is unleashing the ball downfield primarily when someone is wide open. This is an example of a selection bias; the sample of deep passes might be skewed toward those that are likely to be successful. A higher percentage of big throws could result in a lower rate of success.
Nonetheless, the Cowboys possess an offensive playmaker who has the potential to dominate down the field. Dez Bryant has Larry Fitzgerald-esque ball skills, and the third-year player, perhaps ready to mature as a receiver, doesn't need to be wide open to have the ball thrown his way.
One thing is for sure: You'll see Bryant garner a much higher percentage of deep passes in 2012 as compared to his first couple of seasons in the league. Only 18.7 percent of Bryant's targets over the last two years have come on throws of 20-plus yards. Bryant ranked just 51st in deep target rate in 2011 and only 54th in 2010. Despite the modest number of looks, Bryant racked up the fourth-most deep touchdowns in the NFL last season.
Obviously Romo's willingness to heave the football to Bryant deep down the field will be dictated largely by the coverage he sees, and that is of course linked to the Cowboys' rushing success. Even when Murray is breaking off long runs, opposing defensive coordinators might want to stay in Cover 2; the alternative, leaving a cornerback in true man coverage against Bryant, could be a whole lot scarier.