THE PROBLEM OF
MEASUREMENT
Let’s get right to the point: you can tell pretty much
nothing about the quality of a field goal kicker from his field goal
percentage. Aaron Schatz of Football Outsiders wrote back in 2006 that “There
is effectively no correlation between a kicker’s field-goal percentage one
season and his field-goal percentage the next.”
What are some possible reasons for this?
Maybe there simply is not a measurable difference in the
field goal ability of the 32 best field goal kickers of the world.
If you or I tried to kick NFL field goals our success rate
would most likely be zero, so clearly there is a drop-off in ability somewhere.
But if the top, say, 100 kickers alive kick field goals with roughly the same
ability, then of course we would fail to see any meaningful distinction among
them at the NFL level.
Maybe there are differences in skill, but we just can’t
measure them.
A full time starter in major league baseball may rack up
600-650 plate appearances in a season, and even with those sample sizes his
batting average is subject to substantial variance based simply on statistical
fluctuation. So when a placekicker attempts, say 35 field goals a year, a
difference of a few percentage points in his success rate probably tells us
absolutely nothing. Even over the course of multiple seasons or a career, there
would be too much random fluctuation to make field goal percentage meaningful.
Maybe it is a Garbage In-Garbage Out situation.
Perhaps the stat itself is so meaningless that we shouldn’t
be surprised it doesn’t yield useable real world results. Among the obvious
weaknesses of field goal percentage:
1)
A 20 yard field goal counts the same as a 50
yard field goal, despite the fact that the difficulty levels are dramatically
different.
2)
It doesn’t account for blocked kicks, bad snaps,
poor conditions, and other factors beyond the kicker’s control.
3)
Perhaps the most pernicious: kickers who lack
the leg strength for long kicks will not be asked to attempt them, so their
success rate can be inflated because they are only trying kicks with a higher
expected success rate in the first place. Likewise strong-legged kickers will
be asked to try more 50+ field goals, and will obviously fail a substantial
proportion of the time.
4)
A corollary of point 3: a kicker who had a poor
success rate the previous year will likely be used less frequently as the coach
may choose to punt or go for it more often when a field goal would be deemed
difficult. Likewise a kicker who had been notably successful may be asked to
make more difficult kicks, and his success rate would predictably suffer. This could be mistaken for regression to the
mean in the stats when it is actually due to external factors. (Note: I am only
inferring that this effect would occur, but if someone with a stat background
is feeling motivated it would make a pretty cool research piece if you could
figure out a way to study it. Get on it, nerds!)
One way to control for some of these issues would be to
divide up field goal attempts by range. To get some rough baselines for what
sort of field goal success rates we should expect, I’ll steal some numbers from
an old Pro Football Focus article:
“In 2010, kickers were perfect on kicks of less than 20
yards, made 95% of kicks between 20 and 30 yards, 88% between 30 and 40 yards,
74% between 40 and 50 yards, and 60% on kicks beyond 50.”
There’s probably some variance in those numbers from year to
year, but what I’m doing here is just conversational rather than a statistical
study so I will consider them close enough for government work (as the kids
say). We still haven’t helped ourselves
all that much, though. Two big problems:
- * If a full year’s worth of field goal attempts
does not render a useful sample size for a kicker, then the single digit
attempts in each range are even more useless.
- * There is a “bucket” issue. Isolating field goals
of between 30 and 40 yards (for example) is completely arbitrary and based on
the numbers that happen to end in zero. I would guess there is a bigger
difference in degree of difficulty between 31 and 39 yards than there is
between 39 and 40, but that doesn’t get reflected here. If we go back through
NFL history (or at least back to when the kicking style changed in the
early/mid 80s) we could come up with an expected success rate for all 42 yard
FGs, all 43 yard FGs, and so on (in fact, Advanced NFL Stats has done this). But again an individual kicker would never have enough attempts to let
us know whether his performance at various ranges was significantly above or
below average.
I think that by now I have established that you can tell
next to nothing about a kicker’s field goal ability from his overall stats, and
you certainly can’t judge him based on any one particular miss.
THE IMPACT ON
DECISION MAKING
A field goal, by its very nature, is a probabilistic event. Anytime
your kicker lines up for a field goal of between 40 and 50 yards, you can
expect a miss about a quarter of the time.
If your team’s kicker misses and that kick happens to swing the outcome
of a game, the fans, media and to a surprising extent the coaches are apt to
question the kicker’s mental toughness and assign the miss purely to his
alleged inability to perform in high pressure situations. This is absurd given
that the guy had a 25% chance of failure just for walking out onto the field.
(Note: I do not doubt that the ability to perform in high
pressure situations, and many other aspects of psychological makeup, have an
impact on sports outcomes. But it is one of thousands of variable going into
the result, and the habit of routinely holding it up as the only variable worth talking about is not
only lazy analysis but also terribly unfair to the players who are being
judged. The mentally toughest athletes
in the world will sometimes fail because the tasks that are asked of them are
designed to be difficult – that’s pretty much the point of sports.)
And yet, here in DC we have seen a pattern play out that
will be familiar in most other NFL towns as well:
- * Shaun Suisham is kept around for several years
due to his supposed reliability on field goals. When that reliability is called
in to question by a missed chip shot field goal that leads to a 2009 loss
against New Orleans, he is cut.
- * Enter Graham Gano, who despite a strong kickoff
leg is shown the door after the 2011 season due to a mere 73.8% field goal rate
as a Redskin.
- * We then are treated to Billy Cundiff who
continues the strong kickoff ability but is cut after going a mere 7 for 12 on
field goals (58%!).
- * Finally we meet Kai Forbath, who saves the day
with a 17 for 18 performance including an impressive 12 for 12 from 40 yards or
deeper.
Consider the following facts and what they might say about the
logic of the above series of personnel moves:
- * Despite that last unfortunate miss against New Orleans, Shaun Suisham’s field goal percentage as a Redskin was 80.2%. The
career success rate of Morten Andersen, considered one of the greatest field
goal kickers of all time, was 79.7%.
- * According to Pro Football Focus, Graham Gano and
Billy Cundiff ranked first and ninth respectively for average kickoff distance
in the 2012 season. Kai Forbath ranked 36th.
Given everything I have written above, there is little
reason to think that Forbath will continue to make field goals at a much
greater rate than his predecessors. He will almost certainly continue to be inferior
on kickoffs, and those invisible yards matter (in fact the primary thesis of
the Schatz article that I cited to begin this post was that kickers’
compensation should be based mostly on kickoff ability because that is the one
skill in which they consistently differ from each other).
The last thing I want to do is to sell NFL coaching staffs
short, so someone please correct me if I am inaccurately portraying their
handling of kickers. But it sure seems like teams make decisions to cut their
kicker and sign a new one based on the same results-based fallacies that lead
fans and the media to conclude that a kicker is only as reliable as his last
kick. With the exception of something obvious like a botched hold, whenever a
head coach is asked about his kickers’ failures he will usually resort to
something like “you just have to make that kick,” as if that means a damn thing.
I get no indication that NFL kickers are regularly monitored and coached on
their technique, which would actually give an indication of why they missed
field goals and whether that result was bad luck or if the kicker is doing
something that would indicate his struggles are likely to continue.
THE SOLUTION: HIRE
PAUL WOODSIDE (OR SOMEONE LIKE HIM)
Consider this passage from the excellent book A Few Secondsof Panic, written by the sports writer Stefan Fatsis as he embedded himself in
a Denver Broncos training camp and tried to convert his soccer skills to field
goal kicking:
“… I learned the basics of kicking. Where to position my
left, plant foot (about a foot to the left of the ball). How to take a
backswing (left knee slightly bent, upper body straight, left arm extended to
the side for balance, right heel reaching back to the right buttock, right foot
pointed and locked like Baryshnikov’s). How to execute a proper downswing (snap
the lower leg, keep the right foot locked and perpendicular to the body when
striking the ball). How to finish the kick (straight at the goalposts).”
That’s a lot of technique; it sounds every bit as subtle as
a baseball or golf swing. The tiniest flaw can throw everything off. So this
leads me to what I have always thought is an obvious question:
Why don’t NFL teams have placekicking coaches?
In the book Fatsis hires a man named Paul Woodside who
coaches instructional camps for teenage kickers. It is with Woodside – not a
team employee – whom Fatsis consults on his technique and mental approach. If
NFL coaching staffs, even the special teams coaches, are capable of detailed
one-on-one instruction of their kickers, then I am unable to find public
references to it.
Given that one or two missed field goals a year can mean the
difference between a playoff appearance and a fired coaching staff, I am
surprised that proper instruction and evaluation of kickers is not considered more of a
priority.
Suppose a team had a guy on staff whose sole job was kicking
coach. The advantages seem obvious. He could evaluate each missed kick for a
true cause and instruct the kicker either on nuances of technique or mental
approach. If no progress is seen the kicking coach can advise the head
coach/front office that a change would actually be useful. If the correction
does work he saves the team from reflexively cutting the guy and signing a
stranger with no actual reason to believe the new guy is a better field goal
kicker. And by avoiding the unnecessary
cuts, teams will not force themselves to settle for subpar kickoff performance
based on a faulty or incomplete understanding of their current kicker’s field
goal ability.
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