RulesDownload App

Referee Bias: Quantifying the Homer Effect and Officiating Home-Field Advantage

Gil ImberAnalyst IIJanuary 8, 2017

Earlier this month, Queensland's Gold Coast United coach Miron Bleiberg unleashed a colossal diatribe against referee Peter Green after Bleiberg's team lost to Sydney FC, 3-2, in an Australian A-League contest.

Tied at two late in the second half's stoppage-time, Green awarded a pivotal penalty kick to Sydney's Karol Kisel. Kisel effortlessly chipped the PK into the back of the net, earning Sydney FC its decisive go-ahead goal. The match was declared final soon after Gold Coast United restarted the action at midfield.

In his post-match comments, Bleiberg went beyond simply criticizing Green's penalty call; he accused Green of deliberately throwing the game Sydney's way. Bleiberg has criticized Green before and has himself been accused of having "a hidden agenda."

Bleiberg nonetheless compared two types of soccer referees, the "brave" type and what he called the "homey" variety, often interchangeably referred to as a "homer" in the United States.

In discussing the "brave" referee, Bleiberg referred to official Ben Williams, who sent off two Melbourne Victory players during a recent Melbourne home game: "There were 25,000 [Melbourne fans] there and he saw what he saw... the guy was brave."

In discussing the "homey" referee, Bleiberg referred to Green during his team's defeat in Sydney: "All the time, [the homey referee] favors the home team."

Though Bleiberg quickly backtracked, distributing a mea culpa press release a few days later, sometimes the most telling comments are made during the heat of the moment, when a coach is not thinking clearly and is letting emotions get the best of him.

FIFA and Australian A-League referee Peter Green
FIFA and Australian A-League referee Peter GreenMark Nolan/Getty Images

Yet despite Bleiberg's apology, the FFA's inquiry and the overall effort to dust this whole sequence under the rug, the allegations and questions remain: do "homey" or "homer" referees truly exist and how is that manifested?

Several studies have been released over the years outlining sports officials' differential treatment of home versus away teams.

In 2009, University of Bath researcher Dr. Peter Dawson led a group of fellows who analyzed officiating statistics from 1,717 UEFA Cup and Champions League matches.

Though Dawson's study was centered on determining which nationality of referee is the biggest homer—he concluded the answer is Portugese—his study also concluded that referees as a whole tend "to favor home teams."

In 2002, University of Wolverhampton lead researcher Alan Nevill and his crew concluded that crowd noise "influenced referees' decisions to favor the home team."

Nevill asked qualified soccer referees to analyze various challenges which had been recorded on videotape, either with or without sound. Nevill found that when the variable of crowd noise was introduced, the referees called 15.5 percent fewer fouls against the home team.

Talk about home-field advantage.

It is important to note that both studies were confined to post-match analyses; neither study actively observed officials on the pitch.

The common referee shirt's black and white stripes are widely—yet incorrectly—believed to represent impartiality. Instead, the stripes help distinguish officials from players and coaches.
The common referee shirt's black and white stripes are widely—yet incorrectly—believed to represent impartiality. Instead, the stripes help distinguish officials from players and coaches.Ronald Martinez/Getty Images

Regardless, formal and informal analyses all over the globe—from La Liga in Spain to the Thai Premier League in Thailand—have found this alleged "homey effect."

Alas, most of these studies only found the existence of the "homey effect" and stopped there. These studies did not determine whether the homey effect is a subconscious or a conscious phenomenon.

A study led by Harvard's Ryan Boyko, on the other hand, answered this vital question.

Bokyo and his team determined that the "homey effect" operates subconsciously; referees are neutral and impartial in the realm of consciousness.

Specifically, Boyko postulates that "While subconscious referee bias does not necessarily make home advantage unfair, our finding of significant variation in home advantage by referee is hard to accept as fair."

In other words, when the average fan perceives that a referee has called more fouls against the visitors than the home team, the fan is unable to justify this natural and subconscious effect.

The fan then falls prey to psychological repetition and builds a model of referee homerism, that a pro-home team call is not legitimate and is the work of conscious manipulation. This of course, is not true.

Sports officials are human and as such, are subject to human ills. Wertheim and Moskowitz stated it quite clearly: "refs aren't... to blame."

Some studies claim that referees subconsciously crave positive reinforcement, as all human beings do. One such study estimates the homey effect at 15.5 percent.
Some studies claim that referees subconsciously crave positive reinforcement, as all human beings do. One such study estimates the homey effect at 15.5 percent.Doug Pensinger/Getty Images

Moskowitz also theorized the "homey effect" as it relates to referee decision making: "If you can make a call that 50,000 people will agree with or make the call that causes them to say unprintable, nasty phrases at you, it is natural to want to alleviate some of that pressure."

The Los Angeles Times' Douglas Farmer summed it up as "subconscious submission to peer pressure."

All verifiable studies decidedly concluded the "homey effect" is due to subconscious variations in play calling—not due to a conscious attempt to manipulate or "throw" the game.

Sports officials are held to the highest of ethical standards—the idea is to provide each team with an equal opportunity to win.

Officials do not consciously make calls to benefit the home team at great detriment to the visitors. The insinuation of a proficient referee deliberately throwing a game so that the home team will unfairly win is an absurd proposition.

It goes against everything officials across all sports are taught from day one of referee or umpire class.

Employing the "Referees are people, too" angle is a double-edged sword in the world of sports.

On the one hand, playing the card might induce an especially abusive coach to tone down his criticism and see things from another perspective.

On the other hand, such a claim confirms that referees, like coaches, players and fans, fall prey to the adverse effects of home-field advantage.

Yet another reason to play at home.

Where can I comment?

Stay on your game

Latest news, insights, and forecasts on your teams across leagues.

Choose Teams
Get it on the App StoreGet it on Google Play

Real-time news for your teams right on your mobile device.

Copyright © 2017 Bleacher Report, Inc. Turner Broadcasting System, Inc. All Rights Reserved. is part of Bleacher Report – Turner Sports Network, part of the Turner Sports and Entertainment Network. Certain photos copyright © 2017 Getty Images. Any commercial use or distribution without the express written consent of Getty Images is strictly prohibited. AdChoices