JEWISH LAW AND HOME FIELD ADVANTAGE

In Scorecasting: The Hidden Influences Behind How Sports Are Played and Games Won (Excerpted in Sports Illustrated, January 17, 2011) authors Tobias Moskowitz and L. John Wertheim analyze why statistics reveal that home teams have a distinct advantage. That home teams do have a measurable advantage is the same within any sport wherever it is played. That means that home winning percentage is essentially the same in women’s basketball, major league baseball, and professional soccer. For example, the sport with the greatest home filed advantage, Soccer, the host teams in three of Europe’s most popular leagues win approximately 65% of the time. In forty other soccer leagues in twenty-four countries, the home field advantage hovers around 63%. The home team advantage has not shifted in more than a century.

Moskowitz and Wertheim set themselves the task of trying to identify why the phenomenon exists. They posit the various popular theories behind home field advantage and reject each in turn. The idea that the home crowd boosts players’ performance is disputed by free-throw percentages in professional basketball. The virtue of using free-throws as an indicator is that it is the part of the game that isolates one player – the shooter – from the crowd. Statistical analysis shows that over the last two decades the free-throw percentages of the home team and the visiting team are virtually the same: just under 80%.   Further analysis of date from shoot-outs in hockey to field goals in football to velocity of pitches in baseball shows that the home crowd offers no measurable advantage.

The rigours of travel – often cited as a hardship visiting teams must endure – have also proven to show no correlation with losses. Roads teams simply do not lose more games when they travel greater distances: not in basketball, baseball, or football. The so-called “friendlier schedule” that home teams are reputed to enjoy also proves a myth. And the unique home field characteristics like climate, playing conditions, and the design of stadia to exploit the skill sets of the home players have all proven to show no significant advantage in winning percentage.

What these researchers discovered through their comprehensive analyses is that the only factor the statistically accounted for home field advantage was the bias of officials. It seems that the officials are measurably biased towards the home team. The clue to this discovery came from a diligent Spanish grandmother who kept a hand-written record of extra time awarded by soccer referees for stoppages of play during the course of the game. A team composed of a professor from the London School of Economics and two professors from the University of Chicago analyzed the data and determined that over 750 games in close matches when the home team was ahead, the referees reduced the extra time and when the home team was behind, the referees increased the extra time. With this statistical tool in hand, researchers observed the same pattern in the soccer leagues of England, Scotland, Germany, Spain, and Italy. In baseball, researchers have documented that when the game is in doubt, called strikes generally go in favour of the home team. In football, fumbled balls were awarded to the home 8% more than to the visitors. Instant replay has now resulted in changing that disparity.

Researchers are clear to state that there is no evidence that officials are instructed to rule for the home team. Rather, they are subject to severe social pressure. This is what psychologists identify as

conformity. When people are under substantial pressure, they tend to try to alleviate it. And sports officials are human beings. Hence, when the home side pressures officials into ruling their way, it is human nature that they will, unconsciously being swayed by the crowd. This is the only factor, claim Moskowitz and Wertheim, that explains all the disparity in every sport.