from Amazon
Monday, June 14, 2010
Choke effect in soccer
Phil:
Gier Jordet, a professor at the Norwegian School of Sport Sciences in Oslo, reports that, when the score is tied, penalty kick shooters succeed at a 90% rate. But when the shooter’s team is behind by a goal, and presumably there’s more pressure, he succeeds only 60% of the time. Wow. That’s some serious choking. The effect is so large I can barely believe it.
I agree with Phil. I don’t believe it. At the very least, is the sample of teams in the behind-by-1 the same as those in the tied? I would presume that teams that are behind-by-1 are already a below average team (or facing an above-average goalie). Maybe? Even then, I can’t believe 90/60.
Even if the 90/60 are the observations, the sample size must be very limited, such that the only thing you are going to conclude is a non-zero difference (definitely possible), but the true difference I’d be surprised if it’s more than 5% (say 75/70).
The reason is because there must be a huge group of players who are little affected, and a small group of players who MAY be largely affected. But, when you see a 90/60 split, it basically is saying that almost everyone is affected to a great deal. And I don’t believe that human beings at the highest levels of their profession would behave that way.