Goal center width, how to count sequences, and the gambler’s fallacy in soccer penalty shootouts

Abstract

Previous research has reported that the gambler’s fallacy could be detected in goalkeepers’ behavior during penalty shootouts. Following repeated kicks in the same direction, goalkeepers were more likely to dive in the opposite direction on the next kick. We employ here a unique data collection approach and accurately measure the exact location of each ball when crossing the goal plane. This allows us to analyze how different definitions of the goal center width affect the results, and we show that this width indeed affects whether a gambler’s fallacy in goalkeepers’ diving behavior exists. We further augment the data with additional kicks from top international competitions and analyze the extended dataset. We also question whether previous treatments of kicking sequences adequately represent what goalkeepers consider as a run of consecutive kicks to the same side. A different representation of kicking sequences is provided and applied to the data. Overall, we find some evidence for the gambler’s fallacy after sequences of two or three kicks to the same side.