Older men playing chess outside in the city

(Photo by Vlad Sargu on Unsplash)

CAMBRIDGE, Mass. — Chess players are always thinking a few moves ahead, but to win, their attention should also be on a different opponent — air quality. That’s especially the case for popular outdoors chess venues like city parks or other urban areas that players often congregate for challenges. According to a new study by MIT researchers, chess players make more mistakes when exposed to air pollution. Their research finds that cleaner air leads to “clearer thinking” and sharper play.

“We find that when individuals are exposed to higher levels of air pollution, they make more mistakes, and they make larger mistakes,” says study co-author Juan Palacios, an economist in MIT’s Sustainable Urbanization Lab, in a university release.

The World Health Organization estimates that air pollution is responsible for over four million premature deaths every year. One concerning air pollutant is fine particulate matter (PM). These are tiny particles are 2.5 microns or smaller in diameter, emitted into the air from burning materials such as the combustion of cars, coal-fired power plants, forest fires, and open fires from indoor cooking — just to name a few. Excessive exposure to air pollution has a connection to the development of cancer and heart problems, according to studies. In this latest report, scientists are adding poor chess playing to the list.

The research team came to their conclusions after closely studying the matches of 121 chess players in three seven-round tournaments held in Germany between 2017 and 2019. Altogether, the competitors made over 30,000 chess moves. In addition to each player’s chess strategy, the authors measured web-connected sensors located throughout the tournament venue. These sensors measured the changes in air quality during each eight-week tournament, including carbon dioxide levels, PM2.5 concentrations, and temperature.

Chess players make critical late-game mistakes when exposed to air pollution

PM2.5 concentrations ranged from 14 to 70 micrograms per cubic meter of air — similar to the amount of air pollution you would find in cities like Chicago. The team used software programs to analyze chess players’ moves and flag any significant errors in their gameplay. They also took into consideration any other explanations for the subpar performance such as a noisy room and how well their opponent plays.

While carbon dioxide and changes in temperature did not affect the matches, people were more likely to make suboptimal moves when there were higher amounts of airborne pollutants. Chess players showed a 2.1-percent higher chance of making a mistake and the chances of it being a game-changing error increased by 10.8 percent. The study authors suggest air pollution affects a person’s cognition, including their ability to accurately judge and plan moves.

“It’s pure random exposure to air pollution that is driving these people’s performance,” Palacios explains. “Against comparable opponents in the same tournament round, being exposed to different levels of air quality makes a difference for move quality and decision quality.”

When air pollution was high, chess players performed even worse when under time constraints. The tournament chess matches required players to make 40 moves within 110 minutes. Around move 31 to 40, the team found that air pollution increases of 10 micrograms per cubic meter increased the chances of error by 3.2 percent.

“We find it interesting that those mistakes especially occur in the phase of the game where players are facing time pressure,” Palacios says. “When these players do not have the ability to compensate [for] lower cognitive performance with greater deliberation, [that] is where we are observing the largest impacts.”

The world’s best players can’t beat dirty air

Even chess grandmasters are not immune to the effects of air pollution. A replication exercise examining 20 years of games in the German chess league found that even the strongest chess players in the world make more mediocre moves when air quality is low. The study findings suggest that you don’t have to live next to a power plant to experience the consequences of air pollution. While the research focused on chess players, it’s also applicable to office workers who may have trouble focusing because of the low indoor air quality.

READ: Best Air Purifiers In 2023: Top 5 Devices For Cleaner Homes Most Recommended By Experts

“There are more and more papers showing that there is a cost with air pollution, and there is a cost for more and more people,” Palacios adds. “And this is just one example showing that even for these very [excellent] chess players, who think they can beat everything — well, it seems that with air pollution, they have an enemy who harms them.”

The study is published in the journal Management Science.

About Jocelyn Solis-Moreira

Jocelyn is a New York-based science journalist whose work has appeared in Discover Magazine, Health, and Live Science, among other publications. She holds a Master's of Science in Psychology with a concentration in behavioral neuroscience and a Bachelor's of Science in integrative neuroscience from Binghamton University. Jocelyn has reported on several medical and science topics ranging from coronavirus news to the latest findings in women's health.

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