You are a soccer goalkeeper, staring at an opponent about to take a penalty kick. You've got a big space to defend, and you know the odds of blocking the kick are slim–typically less than 20 percent. Wouldn't it be great if you could influence the kicker's decision about which side of the net to aim at, so you'd be prepared to lunge in that direction?

Science to the rescue!

A new study concludes that by standing imperceptibly off-center, a goalie can nudge a kicker to kick toward the slightly larger space.

Researchers at the University of Hong Kong's Institute of Human Performance studied 200 video clips of penalty kicks from professional matches. They noted that even though goalkeepers stood, on average, four inches off-center–creating a space difference of less than 3 percent on either side of them–most kicks were aimed at the slightly larger space.

In additional tests with video monitors, using a scale model of the German goalkeeper Oliver Kahn shown in front of a goal, observers playing the role of the kicker were confident about which side the goalkeeper was closer to when the off-center difference was greater than 3 percent.

A third study, in which players were told to kick only if they believed the goalkeeper was exactly on center, found that people nonetheless kicked when the goalkeeper was off center by up to 3 percent–and more often toward the imperceptibly larger side. Best results come when the goalkeeper stands 2.5 to 4 inches off center–a distance that increases the odds the kicker will aim at the larger side by more than 10 percent–the team reports in the March issue of the journal Psychological Science.