Keeping a penalty in a football match is a complex action. Whether a keeper is capable of stopping a penalty, is dependent on numerous factors. One of the most important factors is the prediction of the direction of the penalty. But what does a keeper need to pay attention to, to have the greatest chance of stopping the ball? This was the question that Savelsbergh tried to answer in his study. He and his research team separated successful keepers and unsuccessful keepers.
“The better keepers saved more penalties and were better in predicting direction and height of the penalties.”
How to save a penalty?
Unsuccessful keepers applied a strategy that didn’t seem to be more effective than pure luck. But what kind of strategy was applied by the successful keepers? Savelsbergh et al. investigated this by studying the eye-movements during simulated penalties. This was done with an eye-head-integration system, which could measure the ‘viewing pattern’ of the keepers. To recreate a real situation, keepers needed to watch a short movie of a penalty, during which they had to move a joystick towards the right direction. The group of successful keepers saved more penalties and were better in predicting direction and height of the penalties. In addition, they dared to wait for a longer time before initiating the movement.
But why was this group so successful? More successful keepers are looking at the stance leg of the penalty taker, where the others looked towards the head of the penalty taker. Previous research indicated that the orientation of the stance leg provides crucial information regarding the direction of the penalty: in 80% of all penalties, the foot of the stance leg is directed in the same way as the shot!
“In 80% of all penalties, the foot of the stance leg is directed in the same way as the shot!”
Information from the shooting leg seems to be much more reliable, but is available too late to decide. Therefore, good keepers seem to observe the stance leg of the penalty taker and make their decision somewhat later. Because of this, the successful keepers needed to make less corrections in their movements and could save more penalties!
Savelsbergh GJ, Van der Kamp J, Williams AM, Ward P. Anticipation and visual search behaviour in expert soccer goalkeepers. Ergonomics. 2005;48(11-14):1686-97.