Milwaukee’s Miller Park is only 90 miles away from Chicago’s Wrigley Field. New Yankee Stadium is over 200 miles away from Fenway Park. The closeness of the Milwaukee Brewers and Chicago Cubs would indicate that they should be rivals.
Brewers vs. Cubs: Regionalism
Folks throughout Wisconsin are likely to identify Chicago as a rival due to the storied tradition that is the Green Bay Packers/Chicago Bears. Milwaukeeans lack a clear rivalry with Chicago in any other sport. There really isn’t direct regionalism between the Chicago and Milwaukee areas like there is in New York/Boston or Los Angeles/San Francisco.