Could Deflated Footballs Have Improved the Patriots' Pass Catching?

Kevin Rudy 30 January, 2015

Deflated footballIn the past week there has been a big commotion over this article that shows since 2007 the Patriots have fumbled at rate that is extremely lower than the rest of the NFL. Why 2007? Because that’s the year the NFL changed their policies to allow every team to use their own footballs, even when they were playing on the road. So if the Patriots were going to try to gain an advantage by deflating footballs, that’s the year they would have started to do it.

Now, there have been several articles pointing out some flaws in the analysis, so I’m not going to get into any statistics that have to do with fumbling. Instead I’m going to look at something else that I think could be affected by deflated footballs.

Dropped passes.

After all, if a deflated football makes it easier to carry, it should make it easier to catch, too. And when your offense is centered around one of the greatest quarterbacks of all time, making passes easier to catch would be a huge advantage. So I’m going to see if we can detect anything fishy about the Patriots' percentage of dropped passes since 2007.

For every NFL team, I obtained the percentage of passes that they dropped in each season from 2000-2014 (via You can get the data I used here.

The 2000-2006 Era

Prior to 2007, the home team provided the footballs used by both teams in the game. Any advantage that you might gain by deflating them would also be gained by the opposing team. So let’s see how the Patriots in the Belichick era (which started in 2000) stacked up to the rest of the league when they couldn’t have gained an edge by tampering with the footballs.

Individual Value Plot

Time Series Plot

From 2000 to 2006, the New England receivers had some of the best hands in the NFL. Only three teams dropped a smaller percentage of passes than them (two of which played in a dome) and their drop percentage was less than the league average 6 out of the 7 years. Were the Patriots able to continue this trend after the rule change in 2007?

The 2007-2014 Era

Take one of the best quarterbacks ever (say, Tom Brady), give him one of the best receivers ever (say, Randy Moss), and the result is the 2007 Patriots, one of the most explosive offenses in the history of the NFL. By the same vein, imagine you take an already good pass catching team (say, the Patriots from 2000-2006), give them an additional advantage in catching passes (say, deflated footballs), and the result should be a superior pass catching team that is unrivaled by any other team in the NFL.

At least, that’s how you would imagine it to work, right?

Individual Value Plot

Time Series Plot

Conspiracy theorists can stop reading now. There is nothing to suggest that Patriots have a drop percentage that is significantly lower than the rest of the league. In fact, their drop percentage after the rule change in 2007 is a full percentage point higher than it was from 2000-2006.

If this data analysis showed that the Patriots did in fact have a lower drop percentage than the rest the league, we could continue to break down the data into specifically outdoor games in cold and wet weather. But with the Patriots drop percentage from 2007 to 2014 already so high, it is highly unlikely we’d reach a different conclusion. If the Patriots have been deflating footballs since 2007, it doesn’t appear to have improved their pass catching at all. So if you want to bring down the Patriots for cheating, you'll have to look somewhere else.