By Max Mulitz
“Although the running game is much more physically demanding than the passing game, coaches should keep in mind that the physical matchups that occur during the running game are not as likely to enable a team to overwhelmingly dominate another team.” Bill Walsh- Finding The Winning Edge
We’ve already looked at at the value of rushing and passing efficiency in terms of wins. But obviously an offense contributes to wins primary through scoring points, so I thought I’d look at how rushing and passing efficiency contribute to overall offensive efficiency. I got Points Per Drive data from SportingCharts for the 2011 to 2015 season and used Rushing and Passing Efficiency data from Pro Football Reference.
First, lets look at a multiple regression on Points Per Drive for each Team Season from 2011 to 2015 (for example the 2011 Arizona Cardinals Offense is one data point and the 2013 Arizona Cardinals Offense is another).
The R-Squared for the model was .68. Here we see passing efficiency estimated to be about three times as important as rushing efficiency, where previously we saw passing around twice as important. This is probably because Net Yards Per Attempt combines Yards per Attempt and Sacks into one metric. Also, because most turnovers happen in the passing game and interceptions are negatively correlated with passing efficiency, by not including turnovers in the model their value will mostly be captured by passing efficiency (since efficient passing teams throw fewer interceptions, but rushing yards per carry and fumbles are uncorrelated.)
Now consider the following charts, that with a trend line plot Points per Drive against Net Passing Yards Per Attempt and then plot Points Per Drive against Rushing Yards Per Attempt.
The relationship between net passing efficiency and PPD is both of a greater magnitude and lower variability than the relationship between rushing efficiency and PPD.
Now consider the following table, which breaks offenses into 4 groups based on offensive points per drive and examines the distribution of team rushing and passing efficiency in those groups.
|All Teams 2011 to 2015|
|Points Per Drive||<1.5||1.5 to 2||2.01 to 2.5||2.51+||All|
|Number of Team Seasons||18||73||57||12||160|
|Max Rushing Y/A||4.8||5.2||5.4||4.9||5.4|
|Upper Quartile Rushing Y/A||4.2||4.4||4.7||4.3||4.5|
|Median Rushing Y/A||4||4.1||4.3||4.2||4.2|
|Lower Quartile Rushing Y/A||3.7||3.8||4||4||3.9|
|Min Rushing Y/A||3.3||3.1||3.4||3.8||3.1|
|Max Passing NY/A||6.1||7.7||7.5||8.3||8.3|
|Upper Quartile Passing NY/A||5.7||6.4||7||7.8||6.9|
|Median Passing NY/A||5.4||6||6.8||7.5||6.2|
|Lower Quartile Passing NY/A||5||5.7||6.4||7.3||5.8|
|Min Passing NY/A||4.2||5||5.3||6.5||4.2|
So to read the chart, from 2011 to 2015, there have been 18 Team Seasons where an offense has failed to score 1.5 Points Per Drive. For those teams, the median passing Net Yards/Attempt was 5.4 compared to a league median Net Yards/Attempt of 6.2 In fact, none of the 18 teams to score less than 1.5 Points Per Drive even had league median passing efficiency, with a maximum of 6.1.
One thing to look at is the middle 50% (Lower Quartile to Upper Quartile) of passing and rushing efficiency for each level of offensive efficiency. The offenses that scored <1.5 PPD had a middle 50% NY/A of 5-5.7, the 1.5-2 PPD offenses had a middle 50% NY/A of 5.7-6.4, the 2.01-2.5 offenses had a middle 50% NY/A of 6.4-7 and the >2.5 PPD Offenses had a middle 50% NYA of 7.3-7.8. Notice that there is almost no overlap between the groups and that there is almost linear improvement seen in offensive quality as NY/A increases.
On the other hand, the middle 50% of rushing efficiency for <1.5 PPD offenses was 3.7-4.2, for 1.5-2 PPD offenses it was 3.8-4.4 for 2.01-2.5 PPD offenses it was 4-4.7 and for >2.5 PPD offenses it was 4-4.3. There is enormous overlap at each level of rushing efficiency. While it seems high efficiency offenses may be less likely to have truly ineffective running games (look at the rising minimums), there are all qualities of rushing efficiency represented at each level of offensive quality.
The data supports the hypothesis that Bill Walsh was absolutely correct when he stated passing efficiency exerts dominant control over rushing in terms of driving the quality of an offense.