Interesting Article on New Proposed Kicking Criteria

Matt Prater is No Kathy Ireland

by TJ Johnson on Jan 17, 2010 9:30 AM MST in Strictly My Opinion 51 comments

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I got robbed!

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If you’ve seen the movie Necessary Roughness, I’m very sorry.  Those are two hours of your life you’re never getting back.

If you haven’t, I’ll save you some time.  The best part of the movie was watching Kathy Ireland play the role of Lucy Draper, a female placekicker.  For a few brief scenes, placekicking somehow seemed…slightly more interesting.

But outside of the rare and fictional supermodel, placekickers don’t get a lot of attention.   Most often they are known for either making or missing a late-game kick (i.e., Scott Norwood), or for their ability to shut down an all-you-can-eat-buffet like Sebastian Janikowski.

But we should make an exception for Matt Prater.  Not only should we be talking more about him, but we should acknowledge one fact right now:

Matt Prater, despite playing at altitude, and without ever having done a Sports Illustrated bikini shoot, was the best kicker in the NFL in 2009.

It’s too bad no one really noticed.  Not the national media.  And certainly not the popularity contest that is the Pro Bowl.

But Prater deserved to go just as much as Elvis Dumervil.  Not only was his field-goal percentage consistent all year, but the Broncos defense should make him an honorary linebacker.  That’s because he was able to effectively and consistently influence the other team’s field position, and in turn, its points potential.

Just how did he do this? Follow me after the jump and we’ll take a look.  We’ll also give you a primer on the value of kickers in general.

How Kickers Are Judged

Traditionally, kickers are judged in two ways.  First, they are judged by their accuracy.  Second, they are judged by the number of points they score.  Simple enough.

Most MHR members (and those who are fans of the Football Outsiders) know these are the wrong metrics with which to judge because they are based on two faulty premises.  First, kicker accuracy is notoriously volatile, both within a season and more specifically, between seasons.  Average and so-called Pro Bowl kickers are going to make a little over 8 out of 10 field goals. Sometimes they’ll achieve a much greater accuracy than this percentage. And the very next year, they’ll fall well below the average.  But there’s no real correlation between a kicker’s accuracy from year to year.   This year Matt Prater was at 85.7%.  Last year he was at 73.5%.  This year Jason Hanson of the Detroit Lions was at 75%.  Last year, he was at 95.5%.

This applies to the all-time greats as well.  Perhaps the two “best” kickers of the last decade, Adam Vinatieri and Broncos legend Jason Elam, reflect this kind of volatility. Here are their career accuracy percentages side-by-side:

Both of these potential Hall of Fame kickers fluctuated from year to year and both had 20-point drops from a previous year. Despite all of this oscillation, their career averages are similar to the averages of all other kickers. So, while we might be overjoyed with our kicker during a specific 4-game stretch or an entire season, and while we even might be tempted to say our kicker is elite if he’s currently displaying above-average accuracy, there’s no real reason to believe it will continue. Absolutely none.

Judging kickers by the traditional points-scored system is also of little value.  Scoring a lot of points from field goals–more specifically, extra points–simply indicates that your offense is scoring a lot itself. This year’s top three kickers in total scoring were Nate Kaeding (San Diego), David Akers (Philadelphia), and Ryan Longwell (Minnesota).  All three of these teams were in the top 11 in points.   So the number of points a kicker scores is simply a reflection of his team’s offense, not necessarily a reflection of how “good” a kicker might be.  After all, chip-shot extra points can really add up.

More important, though, is that the traditional scoring system fails to account for a very important event after the field goal, which is the Expected Points Value of the opponent’s kickoff return.

The Value of Touchbacks And Kickoffs

If all NFL-caliber kickers are going to average around 80% in field-goal accuracy, then what additional value does an individual kicker add?  The answer lies in how they influence field position and the points expectation of the opponent.

A few times this year I have written about a team’s expected points value.  Every down and distance on the field has an expected number of points whether for the offense or defense.  In the case of a touchback, the expected points value for our opponent is -.226.  This means, statistically, over the long term, there is a negative point value associated with our opponent facing a 1st and 10 at their own 20-yard line.  So if our kicker could theoretically get us a touchback on every kickoff, we’d be ensuring (again, in the long-term) a point value for us of .226, or the exact opposite of our opponent’s value (our opponent’s negative values are our positive values).

Since most kickoffs are returned somewhere between the 20- and 30-yard line, it´s interesting to see just how these values change as a result of distance:

From these values, it’s clear that getting a touchback carries the most value for a defense.    At the 24-yard line, the values change from negative to positive, so the ideal situation for a football team is to find a kicker who can generate touchbacks or marginal return yards.  The other alternative is to have such a stellar coverage unit that other team never gets past the 23-yard line.  But the 2nd option is unrealistic.

To drive this point home, let’s try a little thought experiment.  Let’s imagine that we have 11 different kickers.  Each kicker is assigned to one of these 11-yard markers above.  So our first kicker always gets us a touchback.  Our second kicker always puts the opponent at the 21-yard line.  And so on and so forth.   And let’s assume that each kicker has 80 kickoffs during a year (this year’s league average after rounding).  We can simply multiply these 80 kickoffs by the expected points values to show us the total expected points of these hypothetical kickers. The following table shows how this would look:

These are interesting numbers indeed.  The kicker who always gives us a touchback will, over the course of the season, give our team an extra 18.08 points (the -18.08 is a positive number for our team) just through his kickoff ability alone. Conversely, the poorest kicker in the group, whose opponents always begin their drives at the 30-yard line, actually costs our team 38.4 points over the season.   The point differential between the two kickers is an astounding 56.48 points over the course of the season.  So 10 yards matter more than you realize.  Even 1 yard over the course of a season would translate to a differential of 5 to 6 points, or almost a touchdown.

Now that we have a good grasp of this concept we can apply the same points analysis to Prater and other kickers with much more acclaim than he (and more Pro-Bowls).  First, we subtract touchbacks from the total number of kickoffs in order to get the total non-touchbacks of each kicker.  Then we pull the opponent’s average starting field position on kickoffs so that we can estimate an expected points value for each kickoff.  We could have pulled each and every kickoff for each kicker, but the averages provided much greater utility.  Finally we simply add the points generated as a result of touchbacks to the points that each kicker has generated on their other kickoffs during the season.  Here are the results:

First, notice the points as a result of touchbacks.  The only other kicker on this list of esteemed kickers that even touches Prater is Stephen Gostkowski of the Patroits, who generated for his team the equivalent of 4.7 points.   Out of Prater’s 78 kickoffs, he had 28 touchbacks.  This was the equivalent of almost a full touchdown for the Broncos this year.

One might be inclined to say that there is not a lot of spread between Pro Bowler Nate Keading’s 2.03 points and Prater’s 6.32 points from touchbacks, when extrapolated across the entire season.  But consider that 6 points is enough to swing 1 or possibly 2 games per year.  In other words, touchbacks matter.  Touchbacks translate into points.  Points translate into wins.

Prater is even more impressive after taking into account all other kickoffs.  Prater was the only kicker on this list that still had a positive expected points value.   This is due to the fact that Denver’s opponents only started at the 24-yard line. Prater’s leg strength and hang time were simply better than this list of Pro Bowl kickers. So before we even begin counting points scored from field goals, Matt Prater was the only non-kickoff specialist in the NFL in 2009 who had a positive expected points value.

The Value of a Field Goal

A field goal is not worth 3 points, at least not in the way you are thinking.  From an expected points view, on average a field goal is worth 3 points minus the expected points value of where the opposition begins its next drive.  In 2009, the average starting field position for kickoffs was about the 27-yard line.  At the 27-yard line, our opponents have an expected points value of .266.  So, in general, a field goal in 2009 was worth about 2.74 points (.266 subtracted from 3).  The same principle can be applied to touchdowns, but we’ll leave this topic for another time.

This is an important concept because it demonstrates Matt Prater’s value even further.  Every time the Broncos scored a field goal or a touchdown, the expected points value of the opponent’s starting field position could have been subtracted (or possibly added) to the value of the previous field goal.   So the further back Prater pinned the opposition after a field goal, the more the field goal was worth.

Let’s take a look at a real example of this.  In Week 1 against Cincinnati, Matt Prater kicked a field goal with 19 seconds remaining in the 3rd quarter.  When Cincinnati got the ball back, they returned the kickoff to their own 15-yard line.  Since the expected points value of having a 1st and 10 at the 15-yard line is  -.583, the value of Prater’s field goal was actually 3.583 points, since the Bengal’s negative expected points value was positive for the Broncos. If Cincinnati would have returned the kickoff to the 30-yard line, their expected points value for that down and distance would have been .48.  Thus, Prater’s field goal would have been worth 2.52 points since we would have subtracted the opposition’s positive points expectation.

The good news is that we have already counted these field-position values for field goals when we did the analysis of touchbacks and kickoffs.  So this means our last step is to award a full 3 points of value to every field goal for every kicker on our list.  Here’s how Prater stacked up:

To be even more precise, we subtracted the points from those field goals that were missed by each kicker.   One could go through each missed field goal and pull the exact points that were lost as a result of the miss.  Or one could simply use an average NFL field goal of 35 yards and assume that the negative expected points value from the miss would be -2.806 (this is what it costs if you miss a field goal on a typical 4th-and-5 from the 25-yard line).   Or we could simplify the process even further and subtract 3 points for each miss, which is what we did.

The Final Verdict

Now that we’ve explored points from touchbacks, points from kickoffs, and points from field goals, we are in a position of determining which of these kickers had the best season.  We merely add the points generated from touchbacks and kickoffs to the points generated from field goals: