Around the midway point of the 2010, I published an article detailing why teams that throw deep more often generally find more success in the passing game. As I pointed out, there was a somewhat strong correlation between deep pass percentage and yards-per-attempt. I detailed why I think this is the case in that article:
Over the years, defenses have adjusted as to not allow big plays–you see it in Tampa 2 schemes and even Coach Phillips’ defense. Make teams beat you again and again underneath.
If you’ve noticed, more and more teams have transitioned to spread offenses (like the Patriots, Saints, etc.) to combat Cover 2 schemes. The high-percentage passes that are a staple of spread offenses work because of the defenses’ philosophy–don’t give up the big play. Spread offenses are an answer to the Cover 2 scheme.
In recent years, however, I think we’ve started to see defenses adapt. Less and less teams are playing Cover 2, instead emphasizing aggressive play and forcing turnovers. The Saints are again the perfect example, as their scheme is one that will yield the occasional big play, but it creates big play opportunities for their defenders as well.
So, how does all of this relate to how often offenses should throw the ball downfield? I raised the previous points to exemplify that game theory dictates that there is no inherently optimal strategy, simply one that is best at any particular time against your opponent’s specific strategy. Thus, there is no “X” percentage of plays at which it is optimal to go deep, or run the ball, or anything else.
Think of it as a giant game of rock, paper, scissors. When the majority of the league is throwing a rock, it’s pretty obvious that you can take advantage of that by throwing paper. But as the league transitions, so must you. When Cover 2 defenses were in vogue (which is still the case with many teams), the spread offense exposed weaknesses. As more and more teams abandon that scheme, though, offenses must change. The first team to recognize trends and adapt will win. The NFL is really like a huge stock market.
At that point in the season, we saw quarterbacks with a deep ball percentage (defined as throws 15+ yards downfield) of 23+ checking in with 5.17 yards-per-attempt. Of quarterbacks in the 20-23 percent range, the average YPA was slightly lower–5.00. Finally, of quarterbacks with less than one deep throw in every five passes, the YPA plummeted to 4.31.
Of course, there were certainly limitations to this data. First, YPA isn’t the only stat that matters in deciphering a quarterback’s value. We might expect the YPA of quarterbacks with few downfield throws to be slightly lower than other quarterbacks, but those passers also have fewer negative plays. One might hypothesize that the sack rates and interception rates would be greater for quarterbacks who throw it deep more often. Thus, the short-throwing passers might make up for a decrease in YPA by completing more passes and putting their teams in more manageable down-and-distances.
When we analyze the data, however, we see this isn’t the case. The success rate and AYPA (adjusted yards-per-attempt) for quarterbacks with less than 20 percent deep throws is lower than that for passers with 23+ percent deep throws. Note: Success rate is the percentage of throws that lead to an increase in expected points, while AYPA takes into account sacks and interceptions. One of the reasons the AYPA for deep passers is greater than that for quarterbacks who throw short more often is that, as you can see, the short passers actually throw more picks.
So is this data enough to conclude the Cowboys should air it out more frequently? The key, in my view, is personnel. With a starting quarterback who lacks elite “traditional” accuracy (Romo’s completion percentage is tremendous because he’s able to buy time to allow receivers to become wide open, but I wouldn’t describe him as having top-notch accuracy) and receivers who excel at getting deep and attacking the football (Dez Bryant, Miles Austin, and even Roy Williams all possess outstanding body control and ball skills, but none are incredible route-runners), it’s clear to me that a higher percentage of big play opportunities would benefit this team.