CHICAGO >> While there was no shortage of fans who came out to cheer the Chicago Cubs as they took a victory lap during the World Series championship downtown parade today, experts caution the crowd numbers may not be as robust as city officials have claimed.

By Chicago’s Office of Emergency Management and Communication’s Count, an estimated 5 million people lined the 6-mile parade route and gathered at the rally in Grant Park. But — like other official crowd counts — there’s reason to be skeptical, experts say.

“The guestimates are almost always vast exaggerations,” said Clark McPhail, a sociology professor emeritus at the University of Illinois at Urbana-Champaign.

Politics often play a factor in overblown crowd counts. Runaway enthusiasm also could pump up the final tally, McPhail said.

There is a science to calculating crowds. The most common method is to draw a grid and make an estimate based on the average number of people that would fit into each section.

Another way to gauge crowds, particularly in a city such as Chicago, would be to analyze the capacity of buses or trains to deliver millions of people downtown or along the parade route, according Steve Doig, the Knight Chair in Journalism at Arizona State University.

Doig too was skeptical of the city’s tally, which was nearly twice the city’s entire population.

“I’m sure it was a great crowd of very happy fans,” Doig wrote in an email, “just not millions of them.”