The popular perception is that the Green Bay Packers are great because of Aaron Rodgers and the passing offense. And for good reason: Rodgers (and by extension, the entire Green Bay passing offense) is on a record-breaking pace. Rodgers leads the league in completion percentage, touchdowns, touchdown percentage, yards per attempt, adjusted net yards per attempt and adjusted yards per attempt. He’s averaging 11.2 adjusted yards per attempt, the highest mark after a team’s first eight games of any quarterback in over 50 years.
But did you know that the Packers rank 21st in pass attempts this season? I doubt that that jibes with your impression of the Packers as a passing team. The 2007 Patriots — the year Tom Brady carved up opposing defenses nearly every week — barely passed more frequently than the average team that season. The 1999 Rams won the Super Bowl and earned the nickname the Greatest Show on Turf, as Kurt Warner, Marshall Faulk, Isaac Bruce and Torry Holt led one of the great passing attacks in football history. That year, the Rams ranked 15th in the league in rush attempts and 19th in pass attempts.
In all of these cases, the statistics did not tell the true story. Those teams passed so successfully that they frequently found themselves in run-favorable situations. Every N.F.L. fan knows that trailing teams tend to pass more frequently than winning teams, and the disparity is stronger the larger the lead or deficit. For example, teams this season are passing on 74 percent of plays when trailing by 17 to 24 points, but that drops to 44 percent when leading by such a margin. How a game unfolds has a large impact on the ultimate run/pass ratio of a team. To truly understand a team’s offensive philosophy, you need to take into account the scoring flow of the game.
I looked at the play-by-play logs of every game this season, courtesy of Footballguys.com. I excluded all plays in which a team was winning or losing by over 24 points because those plays reveal little about a team’s gameplan (for example, the Colts called 23 pass plays and 23 runs in their 62-7 loss to the Saints; plays in those types of games are counted, but only until the games get out of hand). I also decided to exclude all rushing plays where the runner was the quarterback; many of those plays were probably designed pass plays, but others were designed runs or draws, along with quarterback sneaks and kneeldowns.
Finally, I noted how much the team with the ball was leading or trailing by at the start of each play; that will help to give us a general sense of whether it is a passing or running situation. For example, when the Lions came back from a 20-point deficit against the Vikings, the average scoring margin on Detroit plays was -8.5; not surprisingly, the Lions passed on 74 percent of plays in that game (passing plays include sacks). This past weekend, the Texans jumped out to an early lead against the Browns. Houston’s average offensive play was run with a 14.3-point lead; the Texans ran on 37 of 60 plays (this excludes the Matt Schaub touchdown run and his two kneeldowns at the end of the game). Both Arian Foster and Ben Tate rushed for over 100 yards.
The table below shows the average scoring margin for each “play” by each team this season. Remember, the scoring margin excludes plays where a team has a lead of 25 points or more or trails by such a margin; it also excludes plays that end with the quarterback running. The table will loosely correlate with team strength, but there are several reasons (outside of the scope of this article) to hesitate before using these numbers as a sort of power ranking:
[Note: All statistics in this article are from before the Monday Night Football game between the Bears and Eagles.]
As you’d expect, the Packers have been in front most of the time this season. That helps explain why they haven’t passed as frequently as you might think. As you can see, they rank just 13th in percentage of plays that were called passes:
So we know teams like the Steelers and the Packers have played with large leads, and pass more frequently than a team like the Texans. But how would we compare the 49ers to the Falcons? Or the Patriots to the Redskins? We need to convert “margin” and “pass percentage” to equivalent units. We can do that by looking at each team’s standard deviation in each category.
As you may recall from math class, standard deviation measures how spread out the observations are in a particular set of data. The actual standard deviations aren’t all that interesting here, but the key is that by finding out how far from average (as measured by standard deviation) each team is in each category, we can get a true sense of offensive philosophy. On average, the 32 teams ran offensive plays while trailing by 1.2 points (we would expect the average to be negative, because teams kick off after a touchdown or field goal).
The Texans were 1.8 standard deviations above average in the scoring margin category during Houston’s average play; the Packers were 1.7 standard deviations above average, the Steelers 1.6, and so on. At the bottom of the list, of course, would be the Rams at -1.9 standard deviations from the average (taking the standard deviation won’t change the order of the list; it simply measures the variance in the group.)
What about in the pass percentage category? The average team passed on 61 percent of its plays, using the definition of plays from this article. The Bucs were 1.5 standard deviations above average in percentage of plays that were passed; the Texans were -2.1 standard deviations from the average.
Once we have the “margin” category in the same unit as the “pass percentage” category, the rest of the math is easy. If a team has a low margin, that means it has frequently played from behind. If it is high in the pass percentage category, that means it tends to pass often. To measure how frequently a team passes after accounting for game situation, we simply add the standard deviation number in the margin category to the pass percentage standard deviation number.
The table below presents the results. After the team name, the first two columns are just the earlier data reprinted. The next two columns show how many standard deviations above or below average each team was in scoring margin and percentage of passes called. Finally, the last column shows how pass-heavy the offense truly is, after adjusting for average scoring margin.
Lo and behold, the Packers now look to be the most pass-happy team in the league. The Steelers and the Patriots are also in the top four, and the Saints are not far behind. Not surprisingly, the Jaguars and Chiefs lead the way when it comes to run-heavy offenses, regardless of situation. The Jets have actually been relatively run-heavy this season, but their game situation (trailing often) has somewhat distorted the numbers.
Perhaps the most interesting team? The Ravens. A couple of weeks ago, Terrell Suggs said the Ravens needed to pass less and run more; it’s hard to disagree with him. The Ravens have been extremely pass-heavy this season, once you factor in the game situation. Consider that against the Rams, when Baltimore raced out to a 21-0 lead before the first quarter ended, Joe Flacco threw 48 passes while the running backs had just 17 carries. Suggs’s comments came after the Jaguars loss, when Baltimore had 41 dropbacks against just 12 rushes in a game that was close throughout. Against the Steelers this weekend, Baltimore called 50 passing plays despite leading for a majority of the game.
Chase Stuart is a contributor to SmartFootball.com, Footballguys.com and Pro-Football-Reference.com.
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