The final seconds are ticking off the clock and the opposing team is lining up to kick a game winning field goal. There is no time for another play so the game is on the kicker’s foot. You have a timeout to use.
Calling the timeout causes the kicker to stand around for another minute pondering his fateful task. They call it “icing” the kicker because the common perception is that the extra time in the spotlight and the extra time to think about it will increase the chance that he chokes. On the other hand you might think that the extra time only works in the kickers favor. After all, up to this point he wasn’t sure if or when he was going to take the field and what distance he would be trying for. The timeout gives him a chance to line up the kick and mentally prepare.
What do the data say? According to this article in the Wall Street Journal, icing the kicker has almost no effect and if anything only backfires. Among all field goal attempts taken since the 2000 season when there were less than 2 minutes remaining, kickers made 77.3% of them when there was no timeout called and 79.7% when the kicker was “iced.”
So much for icing? No! Icing the kicker is a successful strategy because it keeps the kicker guessing as to when he will actually have to prepare himself to perform. The optimal use of the strategy is to randomize the decision whether to call a timeout in order to maximize uncertainty. We’ve all seen kickers, golfers, players of any type of finesse sport mentally and physically prepare themselves for a one-off performance. The mental focus required is a scarce resource. Randomizing the decision to ice the kicker forces the kicker to choose how to ration this resource between two potential moments when he will have to step up.
If you ice with probability zero he knows to focus all his attention when he first takes the field. If you ice with probability 1 he knows to save it all for the timeout. The optimal icing probability leaves him indifferent between allocating the marginal capacity of attention between the two moments and minimizes his overall probability of a successful field goal. (The overall probability is the probability of icing times the success probability conditional on icing plus the probability of not icing times the success probability conditional on icing.)
Indeed the simplest model would imply that the optimal icing strategy equalizes the kicker’s success probability conditional on icing and conditional on no icing. So the statistics quoted in the WSJ article are perfectly consistent with icing as part of an optimal strategy, properly understood.
But whatever you do, call the timeout before he gets a freebie practice kick.
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January 14, 2013 at 12:07 am
Danny
And of course, sometimes you end up letting the kicker get a very crucial practice kick from the exact position on the field…
January 14, 2013 at 1:34 am
afinetheorem
An alternative explanation of the pattern is that whether or not you ice the kicker, the kicker isn’t really bothered. When practicing, a kicker will line up 20 or 30 in a row; the mental energy of getting ready for two kicks shouldn’t be a bother. (This may be the post I am most qualified to ever respond to: I kicked for two very good semipro teams before coming to graduate school to study game theory!)
If you want further evidence of this theory, ask why you’ve never seen a quarterback iced when he is down, say, 5 points with 7 seconds to go. If anything, the value of that is higher than icing a kicker, since many offenses tip their playcall at least partially when they line up.
January 14, 2013 at 4:57 am
Jonas
It may be that kickers are ‘iced’ in this way because of a perception that they are not as… how shall we say… psychologically robust, as quarterbacks. This perception may be incorrect, of course, but it follows from the ‘not real football players’ attitude.
Another idea is that, since the kicker’s outcome is completely binary, there is some threshold of ‘noise,’ above which he is unlikely to succeed, whereas quarterbacks can perhaps be knocked off their game a bit without disrupting the entire play.
Neither of these, of course, holds with regards to the New York Jets.
January 14, 2013 at 8:17 am
Mixed Strategies in NFL Endgames « Close to the Edge
[…] can this be useful if you aren’t actually picking a strategy? Jeff at Cheap Talk discusses mixed strategies in the context of icing a kicker at the end of a game. Should an opposing team […]
January 14, 2013 at 10:55 am
Lones Smith
There seems a simple way to test your nice theory. Separate times when the kicker was not iced and knew he could not be iced because the other team had run out of time outs, from times when he was not iced because they chose not to ice him….
January 14, 2013 at 11:39 am
jeff
Yes!
January 30, 2013 at 10:03 am
Taips
re:Jonas quote that
It may be that kickers are ‘iced’ in this way because of a perception that they are not as… how shall we say… psychologically robust, as quarterbacks.
Allow me to go against that: kickers ought to be the ones that are truly psychologically robust. They are the guys that never get to perform in a relatively harmless, low-pressure environment (think 2nd and 1, taking a shot downfield). Instead, not unlike the horns at a symphonic orchestra not playing Wagner, they stay silent on the sidelines until they come in and are suddenly put on a spot with nowhere to hide (The metaphor extends to the problem of horns cooling down and its interfering w/ the tuning)
A quarterback screwing up can rationalise the failure as bad play-calling, the exact defense that would spell trouble, missed blocking assignments, wrong route run by the WR. Kickers have the wind and bad snaps, and they are supposed to compensate for the wind, so…
[ Disclosure : I’m from Europe and I’ve never kicked a US football, or played horns ]