In the past various writers on this blog have considered the economics of the penalty shootout (see here, here, here and here).
A 2010 paper in the American Economic Review by Jose Apesteguia and Ignacio Palacios-Huerta called Psychological Pressure in Competitive Environments: Evidence from a Randomized Natural Experiment is another excellent contribution to this literature and has been recently operationalised.
Using data from 129 shootouts, which resulted in a total of over 1,300 kicks, the authors found that the team the kicked first had a 60% chance of winning. This is illustrated below, with the first team represented by the grey bar, and the second, the black bar.
The conclusion from this is that there exists a significant and persistent advantage to the team the shoots first in a penalty kick shootout.
In order to overcome this problem, UEFA have implemented the “ABBA” system. This has nothing to do with the Swedish Eurovision winners but instead alters the sequence of kicks.
The Football Association (FA) implemented this rule change at the 2017 Charity Shield. The governing body stated that if the game were to finish level after 90 minutes, a penalty shootout would follow that would be similar in structure to the tie-break in tennis.
Operationalised this meant “Team A” would take the first kick, followed by “Team B” taking the second and third penalty kicks. “Team A” would then return taking the next two penalties, and the sequence would repeat itself until a winner was found. Hence the “ABBA” sequence.
As luck would have it Chelsea and Arsenal required penalties to separate them in the 2017 Charity Shield.
Given this change, it will be interesting to start collecting the data that starts to become readily available to see if the problem identified by Apesteguia and Palacios-Huerta (2010) has been overcome.