The Boy Who Cried “Foul!”
Pennisi, Elizabeth. “Soccer and the art of deception.” Science 331 (2011): 280-280.
Although soccer is the world’s most popular sport, it is also widely regarded as showcase for the most serious issues in sports. Allegations of widespread corruption, players feigning injury in order to get favorable calls, timewasting, and irresponsible debt management of clubs are almost common occurrences that continue to tarnish the reputation of the beautiful game. Diving, or a player trying to gain an unfair advantage by diving to the ground and possibly feigning an injury to appear as if a foul has been committed, in particular has plagued soccer at the club and international level alike. Contemporary soccer superstars, including Cristiano Ronaldo, Didier Drogba, Fernando Torres, etc., have become equally notorious for their technique and goal-scoring ability as they have for craftily “simulating” fouls.
Gwendolyn David, Robbie Wilson, and Daniel Ortiz-Barrientos, of the University of Queensland in Brisbane, Australia, have studied the “Art of Deception” and they have found empirical support in the antics of footballers for game-theory predictions about dishonest signals. David et al. researched this problem in the context of signalling theory, or examining communication between individuals in order to establish when organisms with conflicting interests should be expected to communicate “honestly.”
Signalling theory is especially important in studying evolutionary biology and species that “mimic” other species in order to increase their fitness. A popular example is the relationship between the Monarch butterfly, the Viceroy butterfly, and predators of these butterflies. Monarchs are generally foul-tasting due to the cardiac glycosides in their bodies, and predators learn to avoid them. Though many are also toxic, some harmless species of Viceroy butterflies have wing patterns that are virtually indistinguishable from Monarchs, and predators often avoid them too, thinking that they are also toxic. However, if the number of non-toxic butterflies ever outnumbers the toxic species, the mimicry strategy might backfire as predators begin to associate the orange and black wing patterns with palatable food. The same game is played on the soccer field.
Signalling theory predicts that most signals, or fouls, should be honest (actually fouls), or else referees would be more likely to disregard most of the “signals” that they observe. However, game theory also predicts that deception should also increase in proportion to the benefit (closer distances to the opponents’ goal) and the degree to which referees are unable to distinguish between real and fake signals (the referees’ “skill”). David et al. analyzed falls from 60 games, 10 each from the Spanish, German, Australian, Dutch, Italian, and French leagues, and they classified them has legitimate, slightly deceptive (the player was touched by the opponent but exaggerated the effects of the impact), or highly deceptive (little or no contact between the players). They also recorded where the falls occurred on the field, at what point in the match, the score at the time, and whether it was a home or a visiting player.
As game theory predicted, legitimate falls far outnumbered the deceptive falls; only 6% of the 2800 falls were highly deceptive. Moreover, players were 2-3 times more likely to dive when they were closer to the goal where the payoff was massive; statistics show that players score penalty kicks 80% of the time. At the same time, referees were most likely to reward dives that occurred close to goals, which was most likely due to players being farther away and the deception was therefore harder to detect.
Non-soccer enthusiasts often base their impressions of the beautiful game on widely televised events, such as the World Cup, where the stakes are much higher. Unfortunately, these matches are also often littered with players trying to gain unfair advantages. In addition to technology being installed on the pitch in order to accurately detect when goals are scored, David et al. suggest that harsher and more frequent punishments for players who dive are necessary changes that should be implemented to preserve the integrity of the game.