Is it just me, or are the conclusions of the study on goalkeepers and penalties described in the New York Times Magazine this week a little picturesque and arbitrary?
I haven’t read the study, which was published in the Journal of Economic Psychology, to which my subscription has tragically expired, but according to the abstract available online, it involved analyzing the behavior of top-flight goalkeepers during 286 penalty kicks. The scientists found that the goalkeepers were statistically most likely to stop the ball if they stayed in the center of goal, but that the goalkeepers nevertheless dived to the right or the left 94% of the time.
From this, the scientists behind the study concluded that what motivated the goalkeepers to jump was a fear of looking indecisive. As the Times put it:
[T]he goalies are afraid of looking as if they’re doing nothing — and then missing the ball. Diving to one side, even if it decreases the chance of them catching the ball, makes them appear decisive. “They want to show that they’re doing something,” says Michael Bar-Eli, one of the study’s authors. “Otherwise they look helpless, like they don’t know what to do.”
But is that really the most plausible explanation? The study’s authors don’t seem to have tested the conclusion in any way except to translate into the language of economic psychology:
[N]orm theory (Kahneman and Miller, 1986) implies that a goal scored yields worse feelings for the goalkeeper following inaction (staying in the center) than following action (jumping), leading to a bias for action. The omission bias, a bias in favor of inaction, is reversed.
And I can certainly think of possibilities that seem more likely than that goalkeepers are letting penalties go in because they’re afraid of looking silly. For instance, I would guess that I have (unscientifically) watched many, many more than 286 penalty kicks, and I would never have guessed that standing in one place was the goalie’s most effective defensive move. I would have thought that, since penalty takers frequently seem to aim for the corners of the net, those being the spots furthest from the goalie, the goalkeeper should pick a corner and dive toward it. Is it possible that, rather than suffering from a reverse omission bias, goalkeepers had the same misconception and thought that they were making the right choice?
Further, can we be so sure that standing in the middle of the net really is the best move for goalkeepers? Apparently it was on the 286 penalties the scientists studied. But those penalty kicks took place within a totality of understanding in which both goalkeepers and penalty kick takers expected the goalkeeper to dive. If that understanding changed—if penalty takers started assuming that the goalkeeper would stand still more often—then wouldn’t the statistical likelihood of stopping a goal from a given position change as well? Let’s say that all the goalkeepers in the world suddenly started standing still twice as often as they do now. How long would it take penalty takers to start adjusting their aim to take advantage of that new configuration? A month?
Finally, I obviously don’t know anything about the motivations of the scientists who conducted the study. But since their abstract promises that they’ll explore the implications of goalkeeper omission bias for “economics and management,” and since they’re willing to speculate quite airily in the Times about its implications for the current financial crisis (“C.E.O.’s might be tempted to change their corporate strategy, or investment managers to juggle their portfolios, even when staying put is the wisest course”), I’d say there’s some basis for hypothesizing that the aim here is to concoct a metaphor that can be franchised out across a variety of media topics rather than to advance our understanding of soccer or the human mind. Maybe that’s too cynical, but that’s such a common move in the sciences these days that I thought I’d jump at it, even if I’d be better off staying still.
Read More: The Unwritten Peter Handke
by Brian Phillips · December 15, 2008
I’m not sure this is actually a new study. If it is, it owes a whole lot to an older Dutch one described in David Winner’s Brilliant Orange (which I daresay may well be the reason the printing press was invented), though I suppose there’s not THAT much variation you can put into a study of PKs.
Furthermore – and bearing in mind that my understanding of statistics comes almost totally from reading Moneyball – is 286 not too small a number to derive sound conclusions from, anyway?
Martha, the abstract says that the study is from 2007, but it’s possible that they were actually analyzing numbers from an older study. I don’t remember the specific penalty studies in Brilliant Orange nearly as well as I remember the mad-genius-of-penalties character who spent all his energy trying to get the team to read them. Anyway, as you say, most penalty kick studies probably differ only in the extent to which they get noticed by the Times.
Fredo, it seemed small to me, too. Then again, if they can predict presidential elections based on a poll of 700 people in Ohio, etc.
“But those penalty kicks took place within a totality of understanding in which both goalkeepers and penalty kick takers expected the goalkeeper to dive.”
And it depends on who the penalty taker is. A lot of the times I think keepers make a move too early against kickers who are there to place it in the opposite direct of the dive. For example I was hoping Abiatti would delay his move till the last instant against Del Piero. He did and dived the right way but the kick was too good.
Maradona was a ‘placer’ through and through, one who would wait for the keeper to make a move, or bait him towards one side before calming slipping it in the other corner.
Or they could just practice on FIFA ’09 as Sebastian Frey does. Same ‘A.’ present on The Offside Milan boards I wonder?
It’s Amelia who plays FIFA (and credited his save of Ronaldinho’s penalty against Palermo to said “practice”).
I’ve always thought of Frey as more of a PES guy.
Another piece missing from the analysis:
If the keeper stands still and the shot comes in straight, it’s an easy save.
If the keeper guesses left or right correctly, there’s no guarantee he’ll actually stop to the shot. (See Del Piero vs. Abiatti, 16/12/08)
I don’t know how much of it’s down to studying the PKs of various players or intuition in the heat of the moment but Dida seems to delay his move till the ball is struck and with pretty good results. It at least forces the kicker to choose one side of the goal to aim at, if nothing else.
@Peter, yes the same.
The name of the “mad-genius-of-penalties” in Brilliant Orange is Gyuri Vergouw.
The name of this man is Gyuri Vergouw.
I so hope it’s the same person. (How many Gyuri Vergouws could there be, anyway?)
He seems a bit too young, but on the other hand OH MY GOD PLEASE LET IT BE THE SAME PERSON.
Look at the video again, then look at the photos here. It has to be. I love this man!
I attended Joe Machnik’s goal keeper camp in LA way back in the summer of 1990 and he taught basically the same method reported in the Times article – hold your ground. If you don’t move you save what comes down the middle plus some others that your reflexes, a little luck, and some less than perfect strikes will allow. According to Machnik, this method fairs better than the guessing method.
(Worthless side note: I’ve followed this method ever since. My record in over 60 competitive matches since 1990 – 1 PK saved out of 6 faced).