2012 Fumble Luck

by Rivers McCown

This weekend I was finishing up Bill Connelly's new book Study Hall: College Football, Its Stats and Its Stories, which -- quick plug! -- is available in our web store for $8.99. I came upon this passage in one of the chapters breaking down the basics of advanced statistics, from our dear leader:

"I often say I got into this to improve commentary, not to improve how well teams are run," says Aaron Schatz. "I think front offices in the NFL are smarter about things than fans give them credit for being. The trick for me in terms of regular fan acceptance is to get the color commentators and, particularly, the studio analysts used to it. We want the basic concepts to show up on broadcasts –- success rates, yards per down, fumbles luck, understanding the importance of opponent adjustments."

And it was then that it hit me that we hadn't run last year's fumble luck table on the site yet.

If you are new to the party: we don't claim that forcing fumbles is not a skill, nor do we claim that some running backs aren't very fumble-prone. (Bryce Brown, take a bow!) What we claim is that once the pointy ball hits the carpet, there is a lot of luck involved in which team claims the possession that comes with a recovery. In a 16-game season of close games, a lot of games can turn based on a few unlucky bounces on fumbles. These things tend to regress to the mean over the time. To name one example of how quickly a percentage can turn, in 2010, the Oakland Raiders kept a league-high 65 percent of their offensive fumbles, recovering 15 of 23 balls that hit the ground. In 2011, the Raiders fumbled 14 times, and recovered just seven of them.

So looking at the fumble luck stats, knowing that these things tend to regress towards the mean, we can glean a little bit about which teams are likely to be under or overvalued by conventional wisdom. Maybe the team will fumble as much as it did last year, but that doesn't mean they'll lose as many fumbles as they did last year. Those extra possessions can swing a few games.

Without further adieu, the 2012 fumble luck stats:

What jumps out in this table? Well, as Bill Barnwell pointed out last week, the Lions seem to have a pretty good case for a bounceback season based on their fumbles. The only problem is that the team everyone is looking up at in the NFC North, the Packers, were essentially just as unlucky as the Lions -- though they did have fewer fumbles on both offense and defense.

Another team that should be expecting a big regression in their favor this year -- and you'd know this if you read Football Outsiders Almanac 2013 -- is the Kansas City Chiefs. The Chiefs were not only among the five unluckiest teams on both offensive and defensive fumbles, but they also had a startling amount of unlucky interceptions. Alex Smith happens to be pretty good at not turning the ball over in the recent past, so you can certainly see that the Chiefs emphasized fixing this in the offseason.

(And yes, despite having the second-best offense by DVOA last season, the Broncos had the highest percentage of fumbles lost by any NFL offense. When you add that to the cauldron with Wes Welker and the camp rumblings of a hurry-up offense, there's solid theoretical ground to believe they could actually get better.)

On the other side of things, the Browns were lucky on both offensive and defensive recovery percentage last season. The offense has actually been outperforming the league average for a couple of years now -- Cleveland lost 29 percent of offensive fumbles in 2012 and a league-low 28 percent in 2011. If displaced Browns coach Pat Shurmur really did coach his way into a paper bag, as Mike Tanier hypothesized in the Cleveland essay of FOA 2013, perhaps he laid low on the turf and smacked fumbled balls in the direction of Browns offensive linemen. That would conveniently explain all the trip-ups in the running game, too.

Both Atlanta and New Orleans were also on the lucky side of things, which is one of the many little factors that went into us projecting the Carolina Panthers as NFC South champs in the Almanac. The idea that the Saints defense -- the worst in the league by DVOA -- was actually lucky on fumble events is part of the reason our projection system isn't forecasting a quick turnaround under Rob Ryan. Ditto the Falcons as they try to hold steady while replacing John Abraham and Dunta Robinson with Osi Umenyiora and rookies.

As further evidence that these things involve a lot of luck: the Falcons and Saints were among the five teams with the highest percentage of lost fumbles on offense in 2011, then they both dropped into the top 10 lowest in 2012. (Of course, it's not quite as impactful when you fumble as little as New Orleans and Atlanta do, but the point about luck remains.)