In light of the ball deflation scandal currently consuming the New England Patriots, football data analyst Warren Sharp looked at the Patriots’ recent fumble statistics and found some startling results. A slightly different version of this post first appeared on Sharp’s own site. It is reprinted with his permission.
On Wednesday, I investigated whether the New England Patriots outperform expectations in bad weather and found that, yes, they do. Then I remembered this remarkable fact: The 2014 Patriots were just the third team in the last 25 years to never have lost a fumble at home! The biggest difference between the Patriots and the other two teams that did it was that New England ran between 150 and 200 more plays this year than those teams, making the Patriots stand alone in this unique statistic. Based on the desire to incorporate full-season data (not just home games, as a team theoretically would bring “doctored footballs” with it on the road) I performed the following analysis:
I looked at the last five years of data and examined total fumbles lost in all games (as well as fumbles per game) and, more importantly, total offensive plays run. Thus, I was able to determine average plays per fumble lost. The results are displayed in the chart above. Keep in mind, this is for all games since 2010.
One can clearly see the Patriots, visually, are off the chart. There is no other team even close to being near to their rate of 187 offensive plays per fumble lost. The league average is 105 plays per fumble lost. Most teams are within 21 plays of that number.
I spoke with a data scientist whom I know from work on NFLproject.com and sent him the data. He said:
Based on the assumption that fumbles per play follow a normal distribution, you’d expect to see, according to random fluctuation, the results that the Patriots have gotten over this period, once in 16,233.77 instances.
Which in layman’s terms means that this result only being a coincidence, is like winning a raffle where you have a 0.0000616 probability to win. [In] other words, it’s very unlikely that it’s a coincidence.
I actually went back and researched five-year periods for the entire NFL over the last 25 years. The Patriots’ ratio of 187 plays to 1 fumble lost is the best of any team in the NFL for any five-year span of time over the last 25 years. It wasn’t just the best—it wasn’t close:
1. 2010–2014 Patriots: 187 plays/fumble lost
2. 2009–2013 Patriots: 156 plays/fumble lost
3. 2006–2010 Colts: 156 plays/fumble lost
4. 2005–2009 Colts: 153 plays/fumble lost
5. 2007–2011 Patriots: 149 plays/fumble lost
6. 2008–2012 Patriots: 148 plays/fumble lost
7. 2010–2014 Texans: 140 plays/fumble lost
8. 2004–2008 Colts: 139 plays/fumble lost
9. 2006–2010 Jets: 135 plays/fumble lost
10. 1999–2003 Chiefs: 134 plays/fumble lost
There are a few key takeaways. First and foremost, the 187 plays per fumble lost dwarfs even the rest of the best seasons of the last 25 years. Second, the Patriots have been at the top of the NFL since 2007.
Ironically, as my study on Wednesday showed, the Patriots’ performance in wet weather home games mysteriously turned ridiculous starting in 2007. In 2006, they went 0–2. From 2007 onward, they went 14–1.
The next obvious question becomes: Where were the Patriots in this statistic pre-2007? Take a look:
As you can see, the Patriots won their Super Bowls having a below-average rate of fumbles lost given today’s average of 105 plays per fumble lost. But in 2007, something happened to propel them to a much better rate. (You’ll remember, that just so happened to be the same year they went 16–0 in the regular season.) But even looking at these numbers, it’s clear how insane the 187 number is: They are almost running 100 more plays without a single fumble as compared with the 2002–2006 period when they won two of their three Super Bowls.
To further illustrate how these numbers are astonishing, the below graphic lays out clearly how far off the Patriots are from the rest of the league. The Patriots and their 187 plays per fumble lost is far from the bell-shaped curve:
Here’s the same chart as the top one, this time displaying color bands as we move away from the 105 plays per fumble lost average. You can see the darker red band contains all teams but the bottom three and the top three and that the bottom three are very close to the darker red band. Meanwhile, the Patriots are really in a league of their own:
Looking at all fumbles, and not just fumbles lost, we come up with similar findings.
First, it should be noted that teams playing indoors fumble the ball less frequently, the foremost reason being that the ball won’t be wet from precipitation or damp from late-night condensation. The below graphic looks at all fumbles over five-year periods during the last 25 years. As you can see, of the top 25 team-periods, 17 are dome teams, including 11 of the top 15.
As is apparent, the Patriots are the only outdoor NFL team in the last 25 years to average 70 plays per fumble or better. It’s simply uncanny, as the statistics above similarly showed.
The league average from 2010 to 2014 was 50 plays per fumble. For indoor teams, the average was 55 plays per fumble. For outdoor teams, excluding the Patriots, the average was 46 plays per fumble. The Patriots averaged 73 plays per fumble, almost 60 percent more than outdoor teams and almost 50 percent more than the league average the past five years.
As we can clearly see in both near-term and long-term data that dome-based teams (that play at least eight games out of the elements) have an advantage in the fumble department, we can exclude them from comparisons to the Patriots.
If we do, I can produce a chart nearly identical to the one at the very top that looked only at fumbles lost. This one looks at all fumbles, whether lost or recovered. I think the point still remains:
Could the Patriots be so good that they just defy the numbers? As my friend theorized: Perhaps they’ve invented a revolutionary in-house way to protect the ball, or perhaps they’ve intentionally stocked their skill positions with players who don’t have a propensity to fumble. Or perhaps, still, they call plays that intentionally result in a lower percentage of fumbles. Or maybe it’s just that they play with deflated footballs on offense. It could be any combination of the above.
But regardless of what, specifically, is causing these numbers, the fact remains: This is an extremely abnormal occurrence and is not simply random fluctuation.