LONDON — Rachel Marsh can pinpoint exactly when her Chicago Cubs fandom began. It was one of those groundhog days in lockdown in July 2020 when her friend Sarah, who was video calling from Chicago, told her to put the Cubs-Brewers game on. Intrigued, she watched, and was quickly hooked.
Marsh, a 25-year-old teacher who lives in Kent, England, didn’t know the rules, but that was okay: a ton of Google searches and…