With the World Cup approaching the semi final stage and games being decided on penalties I thought it would be appropriate to look at the psychology of penalty kicks. Would goalkeepers be better not moving when facing a penalty?
Action bias is a situation where we would rather be seen doing something than doing nothing. This has been the case in numerous government elections as the voting population like to see some action from politicians when in some cases the best option is to let the economy run its course. President Nixon (US President 1969-74) was a great one for doing something even though it would have been better to do nothing – I refer to the wage and price controls introduced in 1971 – the controls produced food shortages, as meat disappeared from supermarket shelves and farmers drowned chickens rather than sell them at a loss. So when the economy is doing badly the government maybe tempted to intervene, even if the risks associated with the changes not necessarily outweigh the possible benefits. Furthermore if an economy is doing well policy makers may feel that they shouldn’t do anything even though the changes could improve the economy further.
According to classical assumptions in economics, when people face decision problems involving uncertainty, they should choose what to do according to their utility from the possible outcomes and the probability distribution of outcomes that follows each possible action. Bar-Eli, Azar, Ritov, Keidar-Levin, & Schein, 2007
In a 2007 study, Michael Bari-Eli at the Ben Gurion University of the Negev, Israel, analyzed 286 professional soccer penalty kicks. They discovered that goalkeepers almost always jump right or left because the norm is to jump — a preference for action (”action bias”). The goalkeepers jumped to the left 49.3% of the time, to the right 44.4% of the time, but stayed in the centre only 6.3% of the time. Analysis revealed that the kicks went to the left 32.2%, to the right 39.2% and to the centre 28.7% of the time. This means that the goalkeepers were much more likely to stop a kick if they had just stayed put – see table below.
The table above suggests that the decisions taken by the kicker and goalkeeper are made roughly simultaneously. The fact that the directions of the kick and the jump match in 43% of kicks rather than in 0% or 100% of the kicks suggests that neither kicker nor goalkeeper can clearly observe what the other chose when choosing their action.
A goalkeepers’ decision making.
In order to suggest a best option for goalkeepers it is necessary to examine the probability of stopping the ball following each combination of kick and jump directions. The table below presents the average saving chances using the formula
Number of penalty kicks saved ÷ Number of penalty kicks x 100
Jumping left = 20 ÷ 141 x 100 = 14.2%
Staying Centre = 6 ÷ 18 x 100 = 33.3%
Jumping right = 16 ÷ 127 x 100 = 12.6%
The research conclusions state that goalkeepers jump to the right or the left during penalty kicks more than they should. In analysing the 286 kicks Bar-Eli et al show that while the utility-maximising behaviour for goalkeepers is to stay in the goal’s centre during the kick, in 93.7% of the kicks the goalkeepers chose to jump to their right or left. This non-optimal behaviour suggests that a bias in goalkeeper’ decision making might be present. The reason that they suggest is ‘action bias’. However you also need to look at the psychological aspects of a goalkeeper. Former Arsenal and Chelsea goalkeeper Petr Cech said that he never liked to stay in the centre as it might look to the fans that he wasn’t trying. Although he would be in a good position to save a penalty that was kicked down the centre, he would feel a lot worse if he stayed in the centre and the ball went into the goal either side of him.
Bar-Eli, M., Azar, O. H., Ritov, I., Keidar-Levin, Y., & Schein, G. (2007). Action Bias Among Elite Soccer Goalkeepers: The Case of Penalty Kicks. Journal of Economic Psychology, 28(5), 606-621.
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