Placing Fumbles in Context (Part 2)

Continuing my breakdown of fumbles, Part 2 looks at fumbles by distance to go, player position, and quarter.

Distance (to go)

Looking at the entire football field, the breakdown of fumbles by down and distance looks like this (fumbles on kickoffs and punts are excluded):

1st and 10 accounts for the overwhelming majority of fumbles, but it accounts for the lion's share of the down-distance pairings during a game, so there's nothing particularly surprising in that.  

For distances of 10 or greater, 12% of fumbles occur on 2nd down, 5% on 3rd down, and less than 1% on 4th down.  

For distances of fewer than 10 yards, 2nd down accounts for 21%, 3rd down accounts for 17%, and 4th down accounts for 3% of fumbles.

Because the fumble percentages correspond closely to the actual play distribution by distance to go in a football game I'm led to conclude that distance to go is not a significant contributing factor to the probability of a fumble occurring on a play.

Player Position

Across the FBS, QB's accounted for about 50% of fumbles in the opponent red zone. The percentage of QB fumbles decreased steadily as the team approached the end zone. Running backs' percentage of fumbles increased steadily as a team approached the end zone. WRs were most likely to fumble in the middle of the field. Interestingly, DBs accounted for a not-insignificant number of fumbles. I suppose this is following interceptions or fumble recoveries.

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When I look at this chart, absolutely nothing important jumps out at me. While there is some variation in frequency of fumbles between quarters, there's no reason to think that it is due to any reason other than chance.  

Conclusion

And this concludes my breakdown of fumbles.  If there's a useful takeaway from Parts 1 and 2, I think it is the improbable frequency of fumbles on punt returns.  

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What can and can't sports analytics do?

Andrew Sharp at SBNation has a great article called Paralysis by Analysis in which he details his visit, as a confessed analytics skeptic, to the the MIT Sloan Sports Analytics Conference.  This conference, to guys like me, is like making the Hajj to Mecca for the world's muslims.  It has to be done, but everybody knows its damn expensive, so Allah (or in my case, Nate Silver) understands if it doesn't work out.

It got me thinking, along with a negative comment left by a reader this week, that some folks are misunderstanding what I'm trying to do, and what sports data and statistics analysis can do and can't do.

What can't sports analytics do?  It can't predict what's going to happen on the next play, series, inning, snap, or whatever.  It can't explain WHY something happened. And it can't take the place of a coach's experience.

What can sports analytics do?  It can provide insights into aspects of the game that are not readily apparent to someone watching, coaching, or browsing the box scores. It can serve as an early warning to coaches and managers about potential problem areas and trends before they manifest themselves in the box score (at which time it's probably too late).  And it can function as a way to evaluate players and coaches in a (mostly) objective manner.

The negative comment I mentioned above said this:  

After all of that it means really nothing...You still cannot prevent these kind of mistakes, and you surely will never be able to look at these graphs and charts, and decide before the next play "the fumbles a coming, better tell so and so to hang on to the ball".....Pretty much a big ole waste of time.....

The comment was directed at the first part of a two-part piece on fumbles that I wrote earlier this week.  I appreciate the commenter's feedback, but I think he's missing the point.  Or maybe I failed to help him understand the point.

That piece wasn't about saying "this play will result in a fumble".  It was about digging into the limited data available to identify relationships between separate events that might be exploitable.  What I found was that fumbles on punt returns occur far more often than they should if they happened at the same frequency as punts.  They don't, and that is an exploitable nugget of information.  A coach could take that to heart and realize that he needs to place more emphasis (read: time, practice, and coaching) into the act of catching and returning a punt.

Whether the analytics are the low budget work I'm doing or the amazing technology gathering and analysis that companies who went to the Sloan conference are engaging in; we are trying to do the same thing...uncover the hidden information in the game so coaches and players and make better informed decision.

GBR!

Paul

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