When will it be safe for fans to return to Wrigley Field, United Center?

With most of the country under a shelter-in-place order and professional sports leagues having come to a halt, many have wondered when it will be safe for those leagues to restart and fans to return.

Oddsmakers and statisticians from Sports Betting Dime have run projections of the likelihood that a fan would be infected by an asymptomatic carrier of COVID-19 while attending a sporting event. The projections are broken down by city, and factor in each city’s projected COVID-19 peak date — for Illinois that is April 17 — along with various presumptive league start dates.

They looked at nine cities, including Chicago, that have MLB, NBA and NHL franchises and how the probability of infection would change based on different league dates of June 1, June 15 or July 1.

The study assumes continued social distancing measures throughout the summer and further assumes standard game behavior by fans and uses the average crowd size from the previous season for each venue.

The numbers were similar among the three leagues, but they don’t look encouraging for sports fans looking to get back into a stadium anytime soon.

If Major League Baseball opens on June 1 at Wrigley Field (assuming an average attendance of 38,208), 818 people — or 2.16% — would be infected with the coronavirus. With a June 15 start date, that number drops to 204 infections (0.54%), but if MLB were to begin on July 1, there would be 92 people infections (0.24%).

If the NBA or NHL restarted at the United Center with an average attendance of 18,804, there would be 395 people infected (2.12%) with a June 1 restart date. If they begin on June 15, 99 people would be infected (0.53%) and July 1 would yield 44 infections (0.24%).

Nationwide the numbers vary according to the projected peak date of the virus. The projections put Chicago on the lower end of infection rates, with an 88% drop from 2.16% to 0.24% probability of infection if the start date is pushed back from June 1 to July 1. Boston and New York have a projected peak date one day sooner than Chicago on April 16. Their infection rate starts at roughly 0.54% for June 1 and drops to 0.05% on July 1. Miami doesn’t peak until May 2 and therefore their infection rate at an NBA or NHL game is 29.17% for a June 1 start, dropping to 13.82% with start on July 1.

Even with the later July 1 start date and a relatively low infection rate projected for Chicago, the exponentially increasing nature of the virus still means that each newly infected person will contribute to a swift inflation of the curve. Until we have more effective measures in place to combat the coronavirus, fans are a long way away from being able to safely watch sports in a stadium or an arena.