科学美国人60秒:Soccer Goalies Ignore Basic Rule of Probability

Imagine you’re a soccer goalie. Your opponent gets ready to take a penalty kick. You’re crouched in front of the net. The past three kickers have aimed to your left. So which way do you dive? If you said “right,” you’d be in good company. Because when penalty shots repeatedly head in one direction, world-class goalkeepers are more likely to lunge the other way. That’s according to a study in the journal Current Biology. [Erman Misirlisoyemail, Patrick Haggard: Asymmetric Predictability and Cognitive Competition in Football Penalty Shoot-Outs]

This form of misconception—that a string of rights is bound to be broken by a left—is also common in casinos, so much so that it’s called the “gambler’s fallacy.” At the roulette wheel, for example, bettors tend to back black after seeing a run of reds. “We’re due for a black,” the thinking goes. But in reality, the roulette ball is still equally likely to land on either color.

And despite what netminders might think, the same is true for penalty kicks. In fact, researchers studying 36 years’ worth of World Cup and Euro Cup finals found that the direction of penalty shots is basically a coin-flip. 

Ah, but if kickers in the next World Cup were to take advantage of the goalie falling for the gambler’s fallacy, they could really get a leg up. [gooooal]

— Karen Hopkin