Is Tom Brady Better at Home?

All of this talk about deflating footballs begs a natural question: What are the differences in performance in Tom Brady’s performance at home (where the Patriots are alleged to have tampered with the footballs) and on the road (where, based on the existing accusations, they would not have tampered with the balls)?

The following table is a list of all the quarterbacks in the last two seasons who have attempted at least 200 passes at home and on the road. The numbers show are the difference between home and road performance. In other words, a positive number means a higher number at home. Below are the results:

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In the last 2 years, Aaron Rodgers has shown the greatest improvement at home relative to away games. Rodgers ranks first in interception percentage drop, first in increase in touchdown percentage, second in increase in yards per attempt (Brandon Weeden is first) and first by a landslide in QB Rating. Tom Brady is 10th in improvement at home in QB rating, leagues behind Rodgers amazing 37.9 QB Rating jump in home games.

What if we expand the sample to go back to the 2006 rule change where quarterbacks from each team could control the ball? How does Brady look then? (Min 500 attempts home and away to qualify for this sample.)

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Brady has actually been quite poor over the long haul at home, at least from a basic statistical perspective. Brady is well below average in these areas, showing a pretty significant road bias (not home) in performance. The average for these 45 qualifying quarterbacks was an improvement of 3.9 QB Rating points at home, 0.2 more yards per attempt at home, a 0.4% bump in TD% and 0.2% drop in INT%. Brady does throw fewer interceptions at home per pass, but his other numbers actually trend in the opposite direction and are better on the road. His QB Rating is a shade better at home, but again, that indicates abnormally strong play on the road relative to the rest of the quarterbacks in the league.

Fumbling Statistics and Patriot Trends

There has been a lot of discussion and (misinformation) floating around on fumbling. Because fumbling is not exactly a sexy topic, it’s not something that gets a lot of love, perhaps outside of Bill Barnwell’s research on the randomness of fumble recoveries. The purpose of this post is to clarify general fumbling trends, behaviors and how the New England Patriots fit into this puzzle.

For this research, I’m using PFR’s database. I’ll try and highlight wherever possible any gaps in the data.

I. 2007-2014 Totals

Since 2007, the Patriots have the lowest fumbling rate in the NFL. There are a lot of reasons for this — as in, the individual areas in which they excel — and many possible explanations for those reasons (e.g. “they are better coached”). We’ll explore some of these in a moment. First, here are the league-wide fumbling rates from 2007-2014, using both special teams and offensive plays:


The Patriots fumble the least frequently over this time period. Their claim to the top spot is a difference of 3 total fumbles in 7 years over the second-place Atlanta Falcons. Some other observations:

Dome Teams vs. Outdoor Teams (based on home stadium)
Dome team fumble% = 1.83
Outdoor teams fumble% = 1.94%

The sample size is small (9 dome teams), but there is very little, at least on the surface, to suggest playing in a dome reduces fumbling rates. At least not by anything we can detect with these sample sizes and the data parsed this way. There should be no one viewing teams that play outdoor home games as a different set of fumblers than teams playing indoor games at home.

So, how does fumbling break down under a more granular microscope? Do some teams fumble more or less in the special teams than in the run or pass game? (Teams use different, shared “K-Balls” more geared toward kicking on special teams plays). How do QB’s fit in? Pass protection? The following sections take a deeper look.

II. Special Teams vs. Offensive Plays

The league average fumbling rate on special teams and on rushing/passing plays is starkly different. If general common sense weren’t enough evidence, this is overwhelming support that fumbling is not random. This makes sense, as impact/effort/vulnerability and ball security all contribute to a fumble. The plays on special teams are often more violent and more hectic. Here’s the difference:

2007-2014 NFL Averages
Special Team plays fumble%: 2.81%
Offensive plays fumble%: 1.77%

And a breakdown of Special Teams fumbling rates by team since 2007:


III. The Patriots on Offensive Plays Alone

The Patriots have a larger edge over the field when looking at just offensive plays since 2007. This is the impetus for the statistical “analysis” angle that they have been playing with advantageous balls. Allow me to make one comment outside of statistics for a second: High School and collegiate athletes take steroids. Not all make the NFL. The bad can cheat to be average and the great can cheat to be legendary. Thus, nothing can prove a team didn’t cheat. However, we can “prove” that something is either a reasonable outlier or not really an outlier at all, which is where this next figure fits in.


Here New England is well ahead of the league. Second-place Atlanta would have needed 18 additional fumbles in 7 years (is that a lot?) to pull even with the Patriots. Speaking of Atlanta, while New England’s z-score of 2.70 — assuming a normal distribution of fumbling exists — is impressive, but it’s not some anomaly. Atlanta boasts a better z-score over the same time period on special teams, as shown in section II. Statistically, this means that it’s very likely something is causing Atlanta and New England to excel in these areas other than just randomness. Until 2 weeks ago, that something was universally explained by

  • coaching
  • ball security of individual players
  • scheme
  • opponent
  • game situation

and so on…in other words, fumbling isn’t random because there are areas where teams and individuals can excel that allow them to fumble less frequently than others.

IV. Quarterbacks fumble the most

Speaking of quarterbacks, they fumble the most. Since 2007, PFR has 4,822 fumbles on record coming from skilled position players on offense — the QB’s, RB’s, WR’s and TE’s. Of those fumbles, nearly half belong to quarterbacks, a not-so-shocking revelation when we consider all the additional variables in play for a QB fumbling other than simply “running with football.” Quarterbacks have a center-exchange of the ball, a handoff exchange, and most importantly, are smashed by much larger men, often when they are trying to do something other than “run” and might have no idea that they are going to be smashed. (“The strip sack.”)


So the QB fumbling performance of a team will have a sizable impact on the overall offense’s fumbling rate. This means that if a team is equipped with a QB with excellent ball-handling, who makes quick decisions and avoids pressure in the pocket well, he (and the scheme and offensive line, technically), can single-handedly inflate or deflate a team’s fumbling rate. Here are the top fumbling teams by QB since 2007 (Plays include passing attempts, rushing attempts and sacks):


The Quarterbacks of those top teams are some of the least-frequent fumblers in the league. Here are the top QB’s, minimum 500 passing attempts, since 2007. Note, fumble% for QB’s includes their passing attempts, so the number of “plays” involved are passing attempts, sacks and rushes. (min 500 attempts)


While Tom Brady excels here, he isn’t even on the top line. Peyton Manning, with his incredibly low 0.70% fumble rate clocks in at the top (along with former Brady backup Brian Hoyer), which makes for an interesting case study, because Manning switched teams a few years ago. Here are how Manning’s teams fared over the years with and without him.


The 2005 and 2006 numbers are best in the league, posting z-scores of 2.10 and 2.14. Manning is barely clipped by Brady’s Patriots in 2007 (1.18% to 1.13%) only to regain the top spot in 2008 at 0.83%. Only six teams from 2003-2010 posted fumble rates under 1%, and Manning’s Colts did it four times, in addition to a 1.01% season in 2010. Manning left and the 2011 Colts offensive fumble rate plummeted to second-worst in the league. Meanwhile, he joined a Broncos team with the worst 2011 fumble rate (2.56%) on offensive plays and in 2012, helped improve them to 1.28%, good for 10th in the league. The Colts 5-year run from 05-09 was the best of any team since 2003 at 0.98% fumble% over 5 years, narrowly edging the 2010-2014 Patriots at 0.99%.

V. The League Has Improved Ball Security

Everyone has improved their fumble% over the last decade. From 2008-2013 the league-wide fumble% declined every season, before blipping back up in 2014.


Notice that the best fumble season on offense in this period was the incredible 2011 New Orleans Saints season, just 0.54%. The Saints had another banner year in 2013 with a 0.74% rate. While 2003-2010 saw only 6 sub-1% fumble rate seasons from offenses, 2011-2014 produced 12. Three of those 12 were from the Patriots, who added a 0.74% of their own in 2011.

VI. How did the Patriots do It? A Law Firm?

The Patriots not only have excelled with Brady protecting the ball, but in their running game as well. Anecdotally, here is where Bill Belichick has always prioritized ball control, quick to bench talented runners who don’t take care of the ball. The Patriots finished with the best fumble rate at RB from 2007-2014, as shown below:


Benjarvus-Green Ellis never fumbled in 536 offensive touches in New England. If those 511 touches were replaced by running back who fumbled at a league average rate (1.07% for RB’s), the Patriots would have added about six fumbles to their total over this time period. While that may sound like a small amount, New England running backs fumbled a total of 26 times from 2007-2014; five additional fumbles is a 23% increase in total fumbles, and takes the Patriots from 1st in this category down to 11th. (0.92%) In other words, one could say the difference between Green-Ellis and an average ball-handling back is the difference between the Patriots finishing 11th and 1st in this category.

Patriots wide-receivers have not been as stellar over the same period.


They are 12th, slightly above the league average of 2.05%, but don’t stand out here in the way that the RB’s or QB does.

Of course, the other key to the Patriots excelling in these areas is their consistency. They don’t have a number of outlying individual seasons, but instead are very good every year. Focusing on where they really excel — fumbles per offensive play — you can see based on their yearly ranking how their consistency helps them gain a lead over the league in this selected time period (a time period where they have gone 100-28 as a team, grabbed 6 first-round byes and are playing in their 3rd Super Bowl.

Patriots Offensive Rank, fumble% by year
2007: 1st
2008: 4th
2009: 8th
2010: 1st
2011: 2nd
2012: 5th
2013: 19th
2014: 2nd

2013 saw the departure of a number of skilled position player, and included Stevan Ridley coughing up 4 fumbles in 188 touches, for a fumbling rate nearly double the league average at RB of 2.12%. LeGarrete Blount joined the team and fumbled 3 times in 158 touches (1.90%). That’s all it takes in the NFL to have a bad fumbling season.

VII. Fumbling Rates correlate and good offenses

Finally, as you may have noticed, some really good offenses protect the ball. Negatively correlated to fumble% — all around roughly 0.4 correlation coefficients — are the following offensive categories:

Yards (0.37)
1st-Down% (0.39)
TD’s (0.41)

In other words, better offensive teams tend to fumble the ball less. This isn’t universally true — thus the moderate coefficient of 0.4 — as teams with scrambling quarterbacks or teams with relatively bad pass protection might completely buck the trend, just as conservative offensives can do so in the opposite direction. But in general, good offenses, and especially QB’s that are good with the ball, will lead to less fumbling and increased offensive efficacy.