Friday, April 6, 2007

Officiating bias, influence by crowds=home field advantage

Officiating bias, influenced by crowds, affects home field advantage

Study finds that individual referees vary in response to environmental factors

The roar of the crowd may subconsciously influence some referees to give an advantage to the home team, according to a study that examines the results of over 5,000 soccer matches in the English Premier League. The matches were played between 1992 and 2006, and involved 50 different referees, each of whom had officiated at least 25 games within that time period.

Ryan Boyko, a research assistant in the Department of Psychology in the Faculty of Arts and Sciences at Harvard University, led the study, which will be published in an upcoming edition of the Journal of Sports Sciences.

"Individual referees and the size of the crowd present are variables that affect the home field advantage. In order to ensure that all games are equally fair, ideally, all referees should be equally unaffected by the spectators," says Boyko.

Boyko studied the number of goals scored by a team at home versus those scored while away, and found that teams scored 1.5 home goals on average, and 1.1 while away. Crowd size also had an impact on the number of goals scored by the home team, and for every additional 10,000 people in the crowd, the advantage for the home team increased by about 0.1 goals.

In addition to affecting the number of goals scored, the away team received more penalties, implying that referees are making calls in favor of the home team, possibly as a result of the influence of the crowd. Some individual referees are more susceptible to these influences than others. In fact, more experienced referees are less biased by the impact of a large audience, which suggests that they may develop a resistance to effects of the crowd.

Match results within the English Premier League were chosen for study because the games are heavily attended and the teams are located within the same time zone, eliminating long-distance travel as a factor involved with home field advantage. Information about the results of English Premier League games is also widely available online.

While previous research has studied the home advantage with regard to the influence of the crowd, player performance, and referees' decision-making processes, little work has been done on the variation of partiality from referee to referee. While understood to be present in sports that are both judged and scored, earlier studies had also shown that the home field advantage is more pronounced in sports that are subjectively judged, such as figure skating, as opposed to those that are objectively decided, such as speed skating, indicating a relationship between the judging process and the home field advantage.

The findings could suggest ways to increase the fairness of matches by identifying referee susceptibility to the external factors that are present at most sporting events.

"Referee training could include conditioning towards certain external factors, including crowd response," Boyko says. "Leagues should be proactive about eliminating referee bias. The potential is there for a game to be altered because of factors that subconsciously affect the referee."

Thursday, April 5, 2007

Which Catcher’s Mask Works Better?

As Baseball Season Begins, Which Catcher’s Mask Works Better? Kettering University Students Test Traditional and Hockey Style Masks During Research Project

FInspired by professional baseball catcher Mike Matheny’s forced early retirement from major league play, four Kettering University seniors tested the protective properties of catcher’s masks. Their findings support one for foul tips and the other for batter backswings.

Using high speed video, a crash test dummy and a skeet throwing machine, they propelled a baseball at about 100 mph at the dummy wearing both styles of catcher’s mask. Both masks that the group tested were manufactured for professional use by All-Star, a division of Ampac Enterprises.

Crash dummies are instrumented with accelerometers that indicate possible brain or closed-head injuries in humans. The group measured the G-forces exerted on the head in two different types of tests; frontal impact test, simulating a foul-tip, and side impact test, simulating a batter’s backswing striking the side of a catcher’s head.

The traditional style mask performed better on frontal impact. Peak G-force of the traditional mask at this location was 3.763, while peak G-force for the hockey-style mask was 9.814.

The hockey style mask performed better on side impact with a G-force of 13.57 in comparison to the traditional mask recording a value of 32.02.

Their conclusion, the traditional style catcher’s mask is better against a foul-tip, and a hockey-style catcher’s mask is better against a hitter’s backswing. The front impact location was where the foul-tip that ended Mike Matheny’s career struck on the hockey-style catcher’s mask.

The old style is a two-piece design with a metal cage with padding across the forehead and over the cheekbones and chin areas, with no padding on the sides of the head and a helmet with no padding.

The hockey-style looks like a goalie mask, a plastic outer shell over a metal frame and padding underneath with protective coverage back to the ear area and over the top of the head in front.

The research team was Morris “Mo” Roth of Commack, N.Y.; Scott Barel of Sterling Heights, Mich.; Jeff Schulze of Bay Port, Mich.; and Josh Maag of Leipsic, Ohio.

To see photos from the student project, visit and click on: “Foul tip trauma.”