https://phys.org/news/2018-05-emotional-group-boosts-multiday-sports.html

"Event organizers should think about the extent to which they can develop this sense of fans' feeling to be part of a group," said the study's lead author T. Bettina Cornwell, head of the UO Department of Marketing and academic director of the Warsaw Sports Marketing Center in the UO's Lundquist College of Business. "This can happen spontaneously, and organizers should know that."

Events such as baseball, basketball and football games naturally attract loyal fan groups such as those rooting for the home team or alumni and students of an event's hosting organization.