Baseball umpires aren’t blind, they’re breathless, study says
Data shows air quality affects their accuracy
Earlier this month, when an umpire in a Pirates-Brewers game called a pitch just off the outside corner of the plate a strike, the batter, Francisco Cervelli, vigorously shook his head no, and, following an animated discussion, was ejected from the game.
Fans watching on television could see that the called strike was indeed just outside the onscreen, electronically imposed rectangle showing the strike zone and location of pitches thrown to the batter.
In such situations, players question the eyesight and lineage of the ump, and play-by-play announcers may allow that the catcher is doing a good job “framing” pitches, that is, pulling in close balls so they look like strikes.
But they don’t blame air pollution for the missed call. A new study suggests that sometimes they should.
According to the peer-reviewed study, short-term exposure to even low levels of carbon monoxide and airborne particulate pollution causes Major League Baseball umpires to
make multiple mistakes calling balls and strikes.
All umpires make an occasional mistake calling pitches. But, according to the study, the dirtier the air, the more mistakes the home plate umps make.
“We know that air pollution affects the physical performance of athletes and productivity of fruit pickers and other agricultural workers, but this study shows it’s also affecting those doing more skilled, cognitively oriented jobs,” said James Archsmith, lead author of the study and a professor of agriculture and resource economics at the University of Maryland.
Earlier studies by other researchers have found that short-term exposure to carbon monoxide and breathable particles can degrade brain function and cause memory disturbance, loss of concentration, fatigue and impaired judgment, significantly reducing workplace productivity.
To do the umpiring study, Mr. Archsmith and two coauthors, Anthony Heyes at the University of Ottawa and Soodeh Saberian at the University of Manitoba, used a Major League Baseball database to review umpire calls of more than 625,000 pitches in 28 ballparks from 2008 through 2015. They compared the umpires’ accuracy with gametime pollution levels as measured by U.S. Environmental Protection Agency monitors.
They found that higher air pollution levels produced lower accuracy in calling balls and strikes. And that causal relationship is seen far below the federal pollution standards of 9 parts per million for carbon monoxide and 35 micrograms per cubic meter of air for inhalable particulate matter known as “PM 2.5” because they are less than 2.5 microns in diameter, or one-hundredth the width of a human hair.
“We provide what we believe to be the first evidence of a causal effect of shortterm (daily and intra-day) variations in air pollution on the quality of work done by a group of highly-skilled professionals engaged in mentally demanding employment, namely Major League Baseball umpires,” the study states.
Just a one part per million increase in three-hour carbon monoxide levels causes an 11.5 percent increase in incorrect calls by umpires, or an extra two incorrect calls per 100 decisions — about three a game.
Every 10 microgram per cubic meter increase in PM 2.5 particles, measured over 12 hours, causes a 2.6 increase in incorrect calls, calculated at 0.4 extra incorrect calls per 100 decisions.
In an average major league game, excluding pitches that are hit or swung at, a home plate umpire calls 140 pitches, or about half the total number of pitches thrown in a typical game.
And, because pollution levels can, and often do, vary more than 10 micrograms or one part per million during the course of a game, umpires could miss call anywhere from seven to nine pitches per game, Mr. Archsmith said.
The study builds on earlier research that shows that “in addition to causing adverse health effects, exposure to higher levels of pollution can significantly reduce workplace productivity.”
“Our goal was to inform optimal air quality standards, and we were not the first to notice that air quality affects more than human health,” Mr. Archsmith said. “It has hidden costs and here we show that pollution affects people performing cognitive tasks, making decisions on balls and strikes, are less productive and accurate.”
Mr. Archsmith added that the analysis didn’t reveal any bias in pollution-induced mistake calls. That is, the mistakes “don’t tend to favor one team or another.”
Between 2008 and 2015, about 92,600 pitches were called ball or strike by umpires at Pittsburgh’s PNC Park. Of those, the study analyzed about 80,100, discarding the rest because of a lack of pollution data for the day of a game.
Of those 80,100 pitches, umpires missed the call about 13.5 percent of the time, or 10,800 missed ball and strike calls. According to the study findings, pollution at PNC Park was responsible for an estimated 552 of those mistakes or about 4.4 percent of the total missed calls.
“PNC is not the worst ballpark in terms of air quality (impacts),” Mr. Archsmith wrote in an email response to questions.
Three other major league ballparks had higher proportions of mistakes attributable to pollution. He said 5.5 percent of the mistakes at Dodger Stadium in Los Angeles were the result of poor air quality, making it the worst of the 30 major league parks. Turner Field in Atlanta and Angel Stadium in Anaheim, Calif., were also higher.
Only 2.1 percent of the missed calls at Coors Field, where the Colorado Rockies play in Denver, were the result of poor air quality. That’s the lowest pollutionrelated error rate of any park except Chase Field in Arizona, but that’s because the park in Phoenix has a retractable roof, Mr. Archsmith said.
Because there are no pollution monitors near Rangers Park in Arlington, Texas, and Rogers Centre in Toronto, they were not included in the analysis, he said.
The World Umpires Association, the organization representing major league umpires, did not respond to phone call and email requests for comment. The Major League Players Association declined to comment, issuing a short statement saying the study “does not directly involve the PA’s members.”
The Pirates wouldn’t comment on the study and declined to make coaches, staff or players, including Mr. Cervelli, available to speak about it.
Michael Teevan, a spokesman for Major League Baseball, said in an email that the organization has “a different internal process for evaluating the accuracy of ball and strike calls than what they used in the study,” but wouldn’t comment on the study or its findings.
The research relied on the electronic balls and strikes pitch tracking and mapping technology PITCHf/x, used in every major league ballpark from 2008 to 2016. Beginning in 2017, the league switched to a more advanced system called StatCast.
The study, “Air Quality and Error Quantity: Pollution and Performance in a high-skilled, Quality-focused Occupation,” is published online in the October edition of the Journal of the Association of Environmental and Resource Economists.