The impact of turnovers on winning football games
- Updated: June 18, 2013
With offseason programs behind us and training camp still a month away, this is truly the doldrums off the NFL offseason. I like to use this time (well, really the entire offseason) to try and improve my football knowledge by looking at league-wide trends such as quarterback development, rookie wide receiver impacts, and the importance of home-field advantage.
I am excited to continue that tradition this year, and a logical topic submitted itself after a recent round of discussions here at WCSN. We have spent a great deal of time lately—both in articles and in comments—talking about turnovers and the impact they have on teams winning and losing games. I decided it would be fun and informative to look up just how big of an impact turnovers have on a teams’ chances of winning.
The answers that I got were not exactly what I expected, but did provide some insight.
I began my inquiry by looking at teams’ records over a 16-game NFL season and how they were influenced by their turnover differential (the number of takeaways minus the number of giveaways). I looked at all results from the last five years, which gave me 160 data points.
Unsurprisingly, there was a positive correlation between turnover differential and wins (r2=0.36), which you can see in the graph below. For comparison’s sake, the correlation between complete quarterback rating and team wins is 0.33, so turnovers have just as much impact on a team’s season as the quarterback’s performance.
Figure 1. There is a positive correlation (r2=0.36) between an NFL team’s turnover differential and its regular-season win/loss record.
Note, however, that teams have been capable of having successful seasons while struggling with turnovers, highlighted by the 2011 Pittsburgh Steelers, who went 12-4 despite having a -13 turnover differential. Conversely, teams can struggle to win games despite having a positive turnover differential; this happened to the Kansas City Chiefs in 2008 when they had five more takeaways than turnovers but still went 2-14. Clearly, turnovers are important to a teams’ season-long success, but they are not the only thing that matters.
I next wondered how much of an impact turnovers had on an individual game. In order to examine this, I looked at every game from the 2012 season. There were 256 games played in the regular season. One ended in a tie, while 51 featured the same number of turnovers from both teams. That leaves 204 games which featured a winner and one team turning the ball over more than the other. The results are broken down in the table below.
|TO Diff||Wins||Losses||Win %|
In those 204 games, the team that won the turnover battle went 161-43, a winning percentage of 79%. Splitting those numbers up to account for the size of the turnover differential could be useful here. Teams that had a turnover differential of +1 won 68% of the time (roughly two out of three games), a number that increased to 81% for teams that had a turnover differential of +2. When teams had a turnover differential of +3 or better, they won 95% of the time. Looking at the playoffs over the last five years (46 games with a non-zero turnover differential), those numbers are fairly comparable, albeit slightly lower at most levels, although that could be due to a smaller sample size.
NFC North application
One interesting thing we can do in order to apply this to the NFC North is to look at the expected wins for each team in the last two years based on their turnover differential in each game using the probability of winning a regular season game based on their turnover differential alone — so 95% if a team has a turnover differential of +3 or greater, or conversely 5% if its turnover differential is -3 or worse).
The table below shows the expected results for all four NFC North teams over the last two years, compared to their actual number of wins.
|TO Diff||Chicago||Detroit||Green Bay||Minnesota|
We can see that the predicted results are not very far off from what actually happened. Chicago exactly matched their predicted win total, Green Bay came in five games higher than projected, and Minnesota and Detroit both won two fewer games than they were expected to.
For those of you who didn’t bother reading the article, I hope you’ll at least take the time to stop here to see the conclusions before going down to the comments. I present them here in easy-to-digest bullet point:
- Roughly a third of a teams’ season-long success can be explained by its turnover differential.
- The team that turns the ball over less will win the game roughly 80% of the time.
- Odds of winning a game range from 68% for a turnover differential of +1 to 95% for having a turnover differential of +3 or greater.
- These odds are fairly steady in the regular season and playoffs.
What did you think of this article? Do you have any questions about my data or conclusions? Was there an important factor I forgot to consider? Do you have an idea for another topic I could look into? Let me know in the comments below, or send me an email.
I want to call this "Fluke in the Snow"
The June 2013 study from the American Journal of Orthopedics looked at 10 confirmed cases of ruptured hamstrings in the NFL from 1990 to 2008.
While nine of the 10 players in the study returned to play the next season, only five of the 10 played more than one game following the injury.
In addition, two of the 10 players returned and had major injuries occur to the same leg. One suffered a torn Achilles tendon and another re-ruptured the same hamstring (the player was a linebacker). On this note, it is worth noting that Bishop has already been dealing with a strain in the same hamstring he injured in August.
Polygamy seems to be all the rage these days. Now there is another TV show about it. This one is called Polygamy USA.
Hayward in the slot
Shields as the 4th DB in!
I would love to see all 4 of these guys out there at 100% strength at once!
Heat win, inside the spread, on a no-call. Joey Crawford trifecta.
Keepin it classy Packers.
“No, they didn’t. It was more of, they were going to release me if they
couldn’t trade me. And if there was nothing else out there for me, then
we could talk (about coming back).” - Bishop
Green Bay, WI - A newspaper reporter is interviewing a woman in Green Bay who has 12 kids -all boys.
She tells the reporter they are all named 'Jimmy' because it makes it easier for things such as calling them for dinner. "I just yell 'Jimmy!' and they all come running"
'What happens if you want to address them individually? ' asks the reporter.
She replies 'That's easy, I just call them by their father's name'
WARNING: IF YOU HAVE A PS3 WITH A 500GB HARD DRIVE OR BIGGER DO NOT INSTALL THE UPDATE IT WILL BRICK YOUR PS3
And the Heat win game 7 in a landslide.
Fairytale ending, complete.
Written and edited by: David Stern
Going to bed because I have to drive 2.5 hours in teh morning. Don't get too bitter. Game 7 should be good.
Spurs played bad (outside of Timmay) this game. We'll see how it goes in 7. I'm off to play some PS3.
LOL.....I turned the channel at 5 points down with 28 seconds left. Announcer said, there's plenty of time left, I psssttt'd his ass and changed it!
For the life of me, I cannot understand why they kept the ball in Ginobili's hands when he was clearly not feeling it today.
They need to go for a two-point shot. If they get fouled and make it a three-point play, fine. But lobbing up a three pointer would be asinine unless they have the perfect look.
There is no way that ball is out on the spurs. it was a foul. but if you don't call a foul, SA ball.
What the fuck is the ref looking at.
Every single time the Spurs get behind, it is preceded by a period of sloppy offensive play. They need to stay calm.
Duncan ain't got no more juice.
Get this man another ring and let him
ride off in to the HOF on a high note.