- Justin Stombler
Three Steps Back, Two Steps Over: A value-added approach to ranking FBS kickers.
"Good snap, good hold..."
It's a well-coreographed art. The long-snapper fires a spiral back to the holder, who places the ball upright, held only by his index finger and the ground below. The kicker, who began this dance three steps back and two steps over, has already begun his approach.
A giddy-up with his off foot.
A long stride forward.
A plant of the leg.
The entire scene takes place over just a second and a quarter, seemingly insignificant among the sixty minutes of a football game. While it can be the direct cause of a win or loss, often it's left to be considered a footnote in the final tally. Indeed, most kickers make their names on volume, rather than instants; 6 of the top 10 all-time FBS scoring leaders are kickers, all of whom played in the 2010s. However, the number of successful kicks a kicker converts does not itself lead to being great, only to being productive. This led to a question:
How can we rank kickers relative to one another, while controlling for the opportunities they get?
My attempt at answering this is the value-added statistic.
Suppose field goals from 30-39 yards were made 75% of the time. We could say that the expected value of these field goals are 3 points * 75% or 2.25 points. Therefore, anytime a kicker successful converts a kick, he gains 3 - 2.25, or .75, points of value added on that kick, but if he misses he loses 2.25 points. This incremental value is the basis of the rankings.
The first step was to collect data for all FBS kickers. Most of the desired information is available on The Football Database 2020 FBS Kicking Statistics page, while for the rest I manually entered the data using ESPN's Player Stats for each kicker. I only included kickers who had attempted 5 or more field goals on the year.
The head of this dataset looks like this.
The dataset totals 110 kickers. The next step in the process was to total the number of all makes and attempts by yardage to calculate successful FG percentages.
An interetsting note is, not only were no kicks under 20 yards missed all season, but they were also by far the least attempted kicks. Of the 1,416 FGA tracked in this dataset, only 10 of them were from 19 or fewer yards. Only one kicker, Gabe Brkic of Oklahoma, attempted 2 of these. Finally, using these successful FG percentages, we can create expected values for each field goal by simply multiplying the value by 3.
Now that we have obtained our expected values based on 1,416 kicks from the 2020 FBS season, we can calculate each kicker's added value.
Value Calculation and Results
The formula for a kicker's added value is pretty simple:
(#Makes * 3) - (#Attempts * Expected Points) = Added Value
Compute the above for each yardage category and sum the results, take, for example, Brandon Ruiz, the kicker for Mississippi State. He went 4/4 from 20-29, 2/2 from 30-39, 4/5 from 40-49, and 0/1 from 50+.
20-29: 4*3 - 4*2.667 = 1.332
30-39: 2*3 - 2*2.344 = 1.312
40-49: 4*3 - 5*1.946 = 2.270
50-59 = 0*3 - 1*1.417 = -1.417
Total Added Value = 3.497
We can say that Brandon Ruiz added 3.497 points of value to his team above the expected for an average kicker.
With this in mind, we can now look at the full results for all kickers with more than 10 FGA:
There's a lot of information here. It's largely for context and to show how large the spread of value added was across the FBS. Let's break it down. Below, we'll look at some tables that contain the top 10 and bottom 10 kickers.
Top 10 Bottom 10
Much more digestible. A first observation is how spread out the total results are; Cade York and Ethan Mooney combine for an added-value difference of over 20 points! Interestingly, the number of FGA didn't seem to matter much, as the average FGA for the bottom 10 kicker is 17.1, compared to 17.8 for the top 10 kicker.
But, you may wonder, didn't some kickers invariably attempt many more kicks than other kickers? That's a good point, given that some offenses are simply more effective than others, some kickers have much more chances to add (or lose) value than others. Take for example old rivals LSU and Alabama, who offensively have had very different seasons. LSU scored 33 touchdowns in 10 games, among the worst in the country, whereas Alabama got in the end zone 68 times during the season. As could be expected then, Cade York had 21 FGA compared to Will Reichard's 11, so who knows how much value Reichard could have added with 10 additional kicks? That can't be answered for sure, but below are the same charts and tables as above, with value averaged out on a per FGA basis:
As we see, Cade York is no longer in the top spot, and Will Reichard has moved up above him. This could be expected, as Reichard didn't miss a kick throughout the regular season going 12-12, while York went 18-21. The top and bottom 10 tables below:
Top 10 Bottom 10
Many of the same names populate these tables, including North Texas's Ethan Mooney who has ranked last in both Points Per Kick (ppk) and total Added Value. As above, the number of field goal attempts doesn't seem to swing the results either way, as the top 10 now have an average of 15.6, to the 15.3 of the bottom 10.
Thoughts and Conclusions
Misses Matter More...
As could be expected, missing a few kicks can be far more impactful than making them. From inside the 50, a missed kick changes added value more than a made one. The kickers in the top half of the added value chart missed an average of 2.86 kicks, compared to 5.19 for the bottom half. This difference seems miniscule, which is likely because where a kick is missed from is equally impactful. This was the downfall of Ethan Mooney, who was the worst in added value both per kick and overall, but he didn't miss the most kicks (a dubious disctinction that belongs to South Carolina's Parker White and Troy's Evan Legassey with 8 apiece.) The problem lays in the fact that he missed 2 kicks from 30-39, and 4 from 40-49, both of which are larger than average numbers, combine that with a lower than average 14 FGA, and you have a perfect recipe for bad added value. Is Ethan Mooney a bad kicker? By no means at all, but he failed to capitalize on moments where other kickers did.
...So Make The Long Ones
Cade York delivered the highest added value of any kicker on the season, with LSU benefitting to the tune of 11.565 points. He missed 3 kicks, which is not a lot, but it is more than the 7 kickers below him, so what did he do differently? The answer lay in the distance. York went an incredible 6/7 from 50+ on the season, a number of makes that no one else even sniffed. Even more impressive is not only did his 57 yard field goal through the fog in the Swamp to beat Florida add 1.583 points to his total, it was likely the most impactful kick of the season.
On a broader note, the 40-49 yard distance contributed to 248.43 points of change in both directions, by far the most of any distance. This makes sense from a practical perspective. College coaches are more hesitant to let their kickers go from 50+, only 144 attempted on the season, which accounts for 10% of all attempts. So, we see more attempts from the 40-49 yard range, which is still a very difficult range for less accurate college kickers, leading to a larger number of opportunities to add value over the average kicker.
Total v. Per Kick: Who Is The Best?
While Cade York has had an incredible year, complete with the most consequential field goal of the 2020 season, I think Jake Oldroyd's season is even more impressive. A perfect 13/13 season, BYU's Oldroyd sports a stellar 4/4 from 40-49 (compared to 3/4 from York), and 3/3 from 50+. He tallied .868 points per kick, almost 17% higher than the second place Brayden Narveson from Western Kentucky. In theory, if he had kicked as often as York he'd have amassed 18.22 points of added value!
The question is would he have been as consistent in a year that saw him attempt an additional 8 field goals to match York's numbers. There's no real way to know, but suffice to say there's not a fanbase in the country that wouldn't take either of them.
Context Not Included
It's important to note that these numbers don't account for the biggest factor of all, context. While his ranking of 9th in the overall added value is indicative of a fantastic season, Virginia Tech's Brian Johnson would probably love to have do-overs on kicks missed against Miami (lost by 1), Liberty (lost by 3), and two against Wake Forest (lost by 7). Conversly, Baylor's John Mayers had a relatively subpar season (-3.591 points of added value), but considering he broke Baylor's 5 game losing streak with this 30 yarder as time expired against Kansas State, I'm sure he'd rest easy.
If you're interested check out my Github to see the code for this project. The entirity of it was carried out in a Jupyter Notebook with the pandas, matplotlib, and seaborn libraries for Python, along with SQL for creating query tables.