By Bill Barnwell, Football Outsiders – special to BSMW Patriots Game Day
Where I last left off, I was taking a look at the swings in ability that kickers show and wondering aloud whether Adam Vinatieri’s $2.5 million a year contract was worth it. If the Colts make it to the Super Bowl, and Peyton Manning doesn’t re-acquaint his offensive line with the undercarriage of a bus, they may end up being guided to victory by a game-winning field goal off the foot of one Adam Vinatieri. Again, using the Adam Vinatieri Refrigerator Poetry Kit, you can form the basis of many a news article months in advance: “icewater”, “Hall of Fame”, “Disneyland”, “clutch godliness”, and strangely enough, “Jeff George” and a race card are in the bag, too. I think the factory accidentally mixed the Vinatieri kit with the Jason Whitlock Refrigerator Poetry Kit. Anyway, if Vinatieri makes that kick, everything in the following column is moot. Flags fly forever. What I’m going to be taking a look at here, though, is whether spending a healthy amount of money on a kicker results in getting a good season out of your kicker, as well as out of your team.
To try and determine this, I created a database with the statistics of every kicker from 2000 on (the time period in which the USA Today Salary Database has salaries available; if anyone knows of an accurate repository for salary data before that, I’d love to expand the study). I limited the study to the seasons of kickers who had attempted twenty field goals or more, since the attempt is to analyze whether signing a kicker is a good idea, and if a kicker takes fewer field goals than that, he clearly wasn’t the choice made during the offseason, or he failed miserably. This left 170 different kicker seasons over the last six years, for an average of 28.33 kickers per season. For those kickers, I gathered the following statistics:
- Their FG/XP statistic for the season (for more information on this, please see my previous column)
- Points Scored
- Field Goal Percentage
- Team Wins
- Total Salary, according to the USA Today site
I then compared the first four statistics to the player’s salary by determining (well, by Excel determining) the correlation coefficient of the two groups. For those of you forgetting high school math, the correlation coefficient expresses the strength of a relationship between two variables. A value of 1.0 represents a perfectly positive relationship, in that an increase in one variable will always result in an increase in the other; for example, there is a perfectly positive relationship between each beer you drink and the body’s desire for Chinese takeout. Alternately, a value of -1.0 represents exactly the opposite; a perfectly negative relationship. This would be the relationship between each beer you drink and your ability to, say, toe the sideline. A value of 0.0, exactly in the middle, indicates that there’s no relationship between the variables whatsoever, and that the first item has absolutely nothing to do with the second.
The following table shows the correlation between salary and the other variables listed above.
What the data bears out is that there’s a very tiny relationship between kicker salary and performance, if any at all. Furthermore, if you remove kickers who are making the rookie minimum or less, the relationship is weakened even further. Note the column on the right – teams actually get slightly worse (although the relationship is so tiny as to be nonexistent) as their kicker’s salary increases.
Why is that the case when all the other categories show a positive, if slight, relationship? While this isn’t anything proven, it’s a simple fact of the salary cap that money spent on the kicking game has to come from somewhere. Whether that be depth at a position, trading a draft pick away to save the money, or letting a starter go and a backup take his place, the funds have to be made available. These teams with higher-paid kickers may feel the effects in other areas as a result.
Now, let’s look at the average performance of these kickers and their teams. We’ll add two groups here: kickers whose salary exceeds Vinatieri’s average over the first three years of his contract, and those who are closest to it; I’ll form the latter group by selecting the five kickers whose salary is closest to $2,500,000 while above that number, and joining them with the five whose salary is closest to the figure while below it.
What we have there is, to me, real fascinating. While I wish the sample were bigger, the ten kickers with salaries greater than Adam Vinatieri this year and the ten kickers closest to his salary were a part of teams that performed worse than the average team. This doesn’t say that signing a big-ticket kicker is a bad idea; as you will note, the kickers with higher salaries did outperform the average kicker. However, there doesn’t appear to be any sort of positive benefit to a team by signing a better kicker. The correlation between team wins and both FG/XP and FG% isn’t particularly strong, at .159 and .213; the points correlation to team wins, on the other hand, is .596, which innately makes sense: teams that score lots of points tend to win games.
Another way to look at the possibility that Vinatieri’s addition would improve the Colts was to look at the concept of changing kickers itself. From the compiled kicker database, I made a list of all the times teams had switched from one kicker with 20+ attempts to another. That happened, by my count, 24 times from 2000-2005. The teams getting new kickers did see a boost:
So, then, teams replacing their kicker generally see an increase of about a half-win in performance. If you look at the average salary column, though, you see that the new kicker generally makes less than the old one, and that’s not we’re looking to analyze; we’re trying to see whether signing an expensive kicker is a good idea, not a cheap one. Nine teams paid more for their new kicker than they had for their previous one, with the average performances below:
Look at that! Teams who do bring in a more expensive kicker than the previous model increase their performance by nearly a game and a half. Granted, the sample is small, and nearly half that increase is due to the Chargers’ eight win increase the year they replaced Steve Christie with Nate Kaeding, but it’s at least some anecdotal evidence towards making a more expensive kicker a worthwhile investment. The Colts spent $1,800,000 on Vanderjagt in total salary last season.
So, then, was signing Adam Vinatieri a good idea for the Colts? And, alternately, was letting him go a bad idea for the Patriots? The statistical evidence points to several findings:
- Kicker performance oscillates wildly from year to year, even amongst the best
- Spending money on a kicker doesn’t ensure a successful kicker or, necessarily, a successful team
- Replacing a poor kicker with a better one, even if he’s more expensive, results in a better team
With those three things in mind, I can’t see Adam Vinatieri being such an improvement on Mike Vanderjagt that the increased spending the Colts are making on the kicker position is worthwhile. Until Stephen Gostkowski actually gets on the field in an NFL game and/or has to kick a game-winning field goal, it’ll be hard to gage whether the Patriots were right. What appears to be true, though, is that the Colts were wrong.