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Kickoffs into the End Zone: To Return, or Not to Return?

TeeIn the world of Six Sigma, we’re always looking to improve our process. Whether it’s increasing the strength of building materials or improving the way calls are processed in a call center, it’s always a good idea to use a data-driven analysis to determine the best solution to your process.

The same is true for the NFL. Two years ago, the NFL decided to move kickoffs up from the 30 yard line to the 35. This has resulted in more kicks traveling into the end zone. So NFL coaches have a decision to make on their kick return process:

  • Should I have my player take a knee whenever he catches the ball in the end zone?
  • Should I have him return it no matter what?
  • Is there some middle ground where I have him return it sometimes and take a knee sometimes?

This sounds like a perfect opportunity for data analysis! I’m going to use kickoff data from the last season to determine what I would tell my player if I were an NFL coach! (I know, I’ll never be an NFL coach, but I’m still holding onto my dream of being a clock management coach someday.)

How Far Are Kickoffs Going?

Last year, there were a total of 2,525 kickoffs in the NFL regular season (not including onside kicks). Of those, 2,037 went to the goal line or into the end zone. That’s just over 80% of kickoffs that are going into the end zone. So you can see why making the correct decision about how often to return the kickoff is pretty crucial.  

So when a kick goes into the end zone, how far is it going? Unfortunately, my data contains 710 observations that don’t specify distance. The data (taken from advancednflstats.com) only says “kicked into the end zone for a touchback.” I’m assuming these were either kicked out of the back of the end zone, or the returner decided not to field the kick and it bounced through the end zone. So I’m going to ignore those observations (they are all touchbacks anyway), and focus on the remaining 1,327 where a kick returner was able to catch the kickoff.

The first thing I want to know is how many yards deep the kicks are going into the end zone. The following pie chart breaks it down nicely.

Pie Chart

The yards deep are distributed pretty evenly. Five yards and 9 yards are the most common, but none of the yard lines are very different. So as a kick returner, I’d expect to field the ball at a variety of distances inside the end zone.

Now let’s focus on whether or not I should return those kicks!

How Often Are Teams Returning Kicks Out of the End Zone?

Of the 1,327 kicks where I know the returner fielded the punt, 893 of them were returned out the end zone (67%). On average, the returner was able to return the kick just past the 23 yard line. That’s better than starting at the 20 (where the ball would be spotted if the returner took a knee in the end zone)! 

Data analysis over! If kick returners are getting past the 20 when they return it from the end zone, always return it!!!

Well, not quite. We previously saw that kicks range from going anywhere from the goal line to 9 yards deep in the end zone. We need to see if the yard line the returner gets to varies based on where they take the kickoff from. So let’s look at another pie chart, this one showing how deep the kick is when it’s returned out of the end zone.

Pie Chart

This chart is much different. We see that most of the kicks are being returned between the goal line and 5 yards deep into the end zone. Once you get more than 5 yards into the end zone, players are more likely to take a knee. This seems to make sense, as one would imagine the deeper you are in your end zone, the harder it will be to get past the 20.

Let’s see if the statistics agree. Here is a bar chart that shows the average yard line the kicker returned the ball to for each yard deep they were in the end zone.

Bar Chart

In fact, the data indicate that no matter how deep you are in the end zone, you still make it back to about the same yard line. Even when you return from 9 yards deep in the end zone, you’re still making it past the 20 on average!

But what about being backed up in terrible field position? If you return it from deep inside your own end zone, are you more likely to be tackled inside your own 10 yard line?

Bar Chart

This bar chart shows that if you return it from 4 yards deep or shorter, the chance of being tackled inside your own 10 is almost nonexistent. It does increase once you hit the 5 yard mark, but not by much. Nothing is much higher than 5%. So if you return the ball from the end zone, at worst you’re looking at about a 1-in-20 chance that you’ll be tackled inside your own 10. That’s not too high of a risk.

But when you return the ball from your end zone, you’re not looking to minimize your risk--you’re looking for a big play! Or at least some decent field position. So let’s look at one more plot to see the percentage of times the returner makes it past the 30 yard line.

Bar Chart

This shows that you’re much more likely to rip off a big gain than end up with terrible field position. And shockingly the highest percentage of returns past the 30 happened when the ball was returned 7 yards deep in the end zone!

No matter how you look at it, there doesn’t seem to be any reason to take a knee when you field the ball cleanly in the end zone. No matter how deep you are, on average you’ll make it back to the 20. Sure, a small percentage of the time you’ll have terrible field position, but that is more than made up for by the times you’ll have much better starting field position, or even a touchdown!

Comments

Name: Austin • Friday, September 13, 2013

Did you think about taking into account the effect of fumbles on these numbers? For example, would the chance of losing the ball offset the extra 3 yards of field position on average? I would be this would highly change the final answer to the question of whether or not you should bring the ball out, especially since the expected points for a possession barely changes between starting at the 20 and 23.


Name: Kevin • Tuesday, September 17, 2013

Of the 893 kicks that were returned from the end zone, there were 26 fumbles, and 10 of the fumbles were actually lost by the return team. So obviously this is an added risk to returning the kick. However, in the 893 kicks, 7 of them were returned for a touchdown by the return team. So I would say that the risk of losing a fumble is balanced out by the chance that you return the kick for a TD.


Name: Doug • Tuesday, October 15, 2013

Curious... How important is starting field position in relation to chances of scoring? What is the probability of scoring if a team starts at the 20 yard line as opposed to the 30, 40, or 50? You may not score on the return, but I would think your chances of scoring on a drive significantly improve with better initial field position. Special Teams!


Name: Kevin • Wednesday, October 16, 2013

I actually made a regression equation with field position as the predictor and average points as the response in the article below. It turns out that you really have to get past your own 30 for field position to really give you a significantly better chance of scoring.

http://blog.minitab.com/blog/the-statistics-game/going-for-it-on-4th-down-do-the-statistics-say-its-a-gamble


Name: John • Wednesday, October 23, 2013

Kevin - very often on kick returns there is a holding or illegal block penalty on the return team. Does the "Average yard line returned to" consider this? Is this the net starting position including penalties incurred?


Name: Kevin • Thursday, October 24, 2013

John, you make a great point about penalties. Due to the large amount of data (2,525 kickoffs is a lot to gather) I was not able to easily include penalties into the yardage. So I decided to go back and look at the 893 kickoffs that were returned from the end zone and look for the number of penalties that occurred.
Turns out of the 893 kickoffs, there were only 69 penalties (7.7%). That means less than 8% of the kickoffs in my data were affected. And while most of the penalties were holding on the return team, there were a few face mask and late hit penalties on the kicking team. So the penalty doesn't always make your field position worse.
I do agree that any further analysis on kickoffs should definitely include penalties. And I know that including them would alter some of the numbers in the post above. But they occurred so seldom that I don’t think it would affect the conclusion that you should always return the kick out of the end zone.


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