The Baltimore Orioles-Chicago White Sox game at Camden Yards on Wednesday will be played under the rarest of circumstances — in front of an entirely empty stadium. Due to public unrest in Baltimore after the funeral for Freddie Gray, who died this month while in police custody, Orioles officials decided Tuesday to close the game to fans.
Wednesday’s game appears to be a first. According to Baseball-Reference.com’s database, no major league game since 1914 has been staged in an empty stadium. The sport’s official historian, John Thorn, tweeted that the previous record for the lowest attendance at a major league game was six — a mark set all the way back in 1882.
In other sports, however, empty stadiums are a bit more common. For instance, the authors Tobias Moskowitz and L. Jon Wertheim note in their book “Scorecasting” that in Italy alone, more than 20 soccer matches have been held before empty stadiums. The authors use those games, and the research of Swedish economists Per Pettersson-Lidbom and Mikael Priks, to support their case that home-field advantage (across various sports) is mostly driven by referee bias favoring the home team.
The findings from empty-stadium games suggest that fans do influence the refs. In their original paper, Pettersson-Lidbom and Priks found the typical officiating advantage home teams enjoy (at least in terms of foul calls) to be substantially reduced when fans were removed, even after controlling for the specific teams and referees involved.
Research about home-field advantage in baseball has demonstrated that while umpires do show bias toward the home team in terms of strike-zone calls, it doesn’t have much of an effect on who wins. But a later study showed that umpires’ tendencies to vary the shape of the strike zone in favor of the home team became heightened as the leverage index of the game situation increased.
In other words, if it’s the case that baseball umpires are influenced by pressure of the crowd around them — particularly in big moments — the Orioles will be playing under unusually neutral conditions for a game at Camden Yards.
It goes without saying that one game, however crowdless, isn’t much of a sample in baseball. But the effect it will have on the umpires is an additional wrinkle to keep an eye on during Wednesday’s unique matchup.
UPDATE(April 29, 11:55 a.m.): After reaching out to Baseball-Reference’s Sean Forman, we learned that the attendance number we quoted for a 1930 Giants-Reds game, 10, may be incorrect due to a clerical error in Retrosheet.org‘s data. The reference to that game has been removed.