Home-Ref Advantage?
"Kill him! Kill the umpire!" shouted someone on the stand;
And it’s likely they'd have killed him had not Casey raised his hand.Ernest Thayer’s classic 1888 poem Casey at the Bat illustrates the timeless nature of every sports fan’s guilty pleasure: criticizing the officials. Umpire, referee or judge, sports’ on-field arbiters are tragic figures, objects of scorn and derision. Despite the necessity of their presence and the unseen effort they provide, officials rarely get any love from the crowd. Yet even with the complaints of the stricken multitude, a consistent home-field advantage exists across the board. The home team wins about 54% of the time in Major League Baseball, nearly 60% of NFL games, and even slightly more often in the NBA. Quite a few factors surely play a part in the advantage, including familiarity with the home arena, fewer travel demands and (usually) supportive crowds. But might these same disdained officials help out as well? To put in another way, I dare pose the unthinkable: Should the home crowd actually be thanking the referee?
Data does support the idea that umpires and referees make more calls favoring the home team. In baseball, this fact is most clearly evident in the calling balls and strikes. Taking a look, the umpire calls about 7% more balls for the home team and 5% fewer strikes. In the NBA last year, away teams were called for an extra foul per game, resulting in 1.4 extra free throw attempts per game for the home squad. The most obvious explanation for this discrepancy could be the end-of-game scenario, when the losing team purposely commits fouls in order to get the ball back. However, these fouls are unlikely to be “shooting” fouls, where there is still a 0.5 foul discrepancy favoring the home team. Similar results have been reported in soccer and boxing (cricket has no such problem, in case you’re wondering).
Notably, crowd size appears to play a role in the penalty advantage held by the home team. In English and Scottish soccer, the discrepancy between home and away penalties is greatest in the top leagues, which have consistently higher attendance. Of course, the phrase “correlation does not imply causation” is hammered into the heads of every beginning psychology or statistics student. I’m not exaggerating – a Google search of the quoted phrase displays its prevalence. In the case of the soccer example, this warning reminds us that the mere fact of the referee calling more fouls on the home team does not necessarily mean there is a bias. Maybe the home side is just playing better (due to rest or familiarity, for instance), and the visiting team has to commit more penalties in their attempt to keep up. What we need is a controlled experiment (we are literally going through my first four weeks of Psych 100).
Aaron Nevill and colleagues did just such an experiment. Instead of the arduous undertaking of controlling crowd behavior (particularly in England, though there are intriguing ways to go about this), experienced referees viewed clips of incidents between home and away soccer players (footballers, for you English traditionalists). The refs were asked to judge the clips as they would a normal game. Half of the refs viewed the clips with the original crowd noise, the other half with no noise at all. Significantly fewer fouls were awarded against the home team in the noise condition compared to the silent condition, consistent with an effect of crowd noise to bias referee decision-making towards the home squad.
We can probably discount the theory that referees are actively trying to appease the home crowd. I tend to still view our sports judges in a positive light, a fault I attribute to being raised by one (though in eighth grade my umpiring dad called a third strike on a curveball around my ankles, an absolutely terrible call). I think officials genuinely try to make the correct call, despite any external circumstances. But officials are human, with perceptual limits, and visual attention is subject to all sorts of outside influences.
There are a couple of reasons why referees subconsciously favor the home team. For one, crowd response may act as a type of pressure to conform. When an individual has a desire to be correct, he or she may rely on what social psychologists term informational influence. This differs from plain ol’ peer pressure – here the referee is swayed by the opinions of others in an uncertain situation. So as the ref is focusing on a tight challenge in the penalty box, his lips pursed around the whistle and unsure whether to act, the fact that 50,000 screaming fans are pointing out an infraction might be just enough for him to pull the trigger. Likewise, when silence dictates that not a single person saw their beloved power forward nick the arm of the shooter, the uncertainty veers towards a no-call (based on the Nevill data, this situation may in fact be more common). Note that these are not conscious cognitive processes – the decision is made nearly instantaneously.
Uncertainty is the key element in this scenario. It’s as if you are a movie reviewer trying to establish an unbiased opinion. The job isn’t so hard if you watch The Godfather. Nor, on the other end, if you are watching Weekend at Bernie’s 2. But if you are watching some middling family film, deciding between two stars or three, the audience reaction might be just enough to bump the rating up half a star (or thumb). That’s why laugh tracks work, but only if you aren’t overly aware of them. Now condense all that subconscious influence into about two or three seconds (max) of evaluation. The crowd’s opinion, voiced or unvoiced, might be enough to tip the decision in favor of the home squad a few times per game.
To some degree, crowd noise also likely acts as negative reinforcement, the same technique that has been heartily employed by ruler-bearing nuns for years. Here, the audience reaction plays a role in aversive conditioning, in which actions paired with adverse consequences are avoided if possible. It’s a basic learning process: behave properly (favor the home team) and evade punishment. This all depends on how the ref views the crowd’s catcalls; in laboratory studies, a strong stimulus (think shock therapy) is usually necessary to induce this sort of conditioning.
Referees actually report that “making a bad call” is the most stressful aspect of the job, and yes, refs do sometimes realize that they have made a mistake. All humans (even soulless referees) have a natural instinct to avoid stress with defense mechanisms, many of which are automatic. In this case, since overturning your own call is not really an option, there are two ways to avoid the stressor: 1) Avoid making a bad call (easier said than done), or 2) Avoid thinking about it (don’t listen to your psychiatrist – repression is a fantastic way to avoid stress).
Here’s where the crowd comes into play. The loudest and most colorful expressions directed towards the referee follow a bad call against the home team. So while hearing a recommendation for prescription eyewear for the millionth time may not be particularly stressful by itself, the crowd’s reaction does hamper the ability to forget a bad call. The optimal solution is therefore to limit bad calls against the home team, best accomplished by limiting all fouls against the home team, particularly in uncertain situations.
Sound far-fetched? Let’s take an example where this influence is maximized. You’re refereeing at the United Center in Chicago in the 1997, and you call Michael Jordan for reaching in. You are going to hear it from the crowd. And if that call is even close to being wrong, prepare yourself for an onslaught of verbal #, % and @s. Those pound signs really %#$@&# with repression. So we can predict that star players (where the crowd response is greatest) are called for fewer fouls at home. No red herring here – that’s exactly what has been found: star players are the greatest recipients of the home-ref advantage.
Efforts to limit the effects of crowd noise have primarily dealt with maintaining communication between players and coaches, such as the installation of headsets in the quarterback’s helmet. Within the human realm, there’s probably not too much the leagues can do to minimize the consequences on officials. Hiring more deaf referees is an option, as is drastically increasing pay (which might alleviate stress), but neither is likely to happen any time soon. Some sports have started to use robotic judges for certain decisions to eliminate the human element. In tennis, players’ challenges of line calls are now reviewed with an electronic system. A soccer ball is in the works that can automatically detect when it has crossed the goal line. And baseball has experimented with the Questec system for a few years now, which informs the league office on how well umpires are calling balls and strikes. Perhaps then we should just be prepared for the inevitable. I, for one, welcome our new robot overlords.
Revisiting our original question: Should referees actually be thanked? Yes – but don’t. In showing anything but the utmost disrespect for the official, you are decreasing the stress that Joe Referee feels. Your well-placed outrage or silence at the game’s critical moments provide a subtle influence on the officials that might just make the difference. Keep up the good work. Sorry, Dad.
References
Lehman DR, Reifman A. 1987. Spectator influence on basketball officiating. J Soc Psychol. 127(6): 673-75.
Sportsology
You probably didn’t learn about the scientific method in your junior high gym class, and not too many post-game interviews touch on quantum theory. But don’t be fooled: the athletic and scientific worlds are not such strange bedfellows. Boxing, for instance, is often called “the sweet science.” And no less an expert than Ted Williams, perhaps baseball’s greatest batter, described his craft in his book, The Science of Hitting. We turn our focus to this intriguing relationship here in Sportsology, where we endeavor to examine the world of sports with a scientific eye. Sportsology will explore athletic topics you never knew you cared about, from the physics of the curveball to Olympic abstinence. We hope to arm you with knowledge to, at the very least, make you the most annoying person at the sports bar.