CHICAGO | For decades, the rivalry between the Cubs and White Sox was relegated to exhibition contests or charity events.
But with the introduction of interleague play in 1997, the rivalry between the Cubs and White Sox has intensified as the games' importance has elevated.
"It's a fans' game, and the fans really like it," White Sox broadcaster Steve Stone said.
"From a players' standpoint, it's kind of an interesting dynamic because if you lose the series you talk about how unimportant it is, and that the most important games are within your division.
"If you win the series, you talk about how each and every win is of critical importance because you have some greater good in mind."
Though each team is playing below .500 ball, the rivalry hasn't diminished, at least to the fans.
"The teams are so terrible," said White Sox fan Rob Allard. "This is it. This is our Stanley Cup, our World Series. If we get swept, I'm not going back home."
A mere nine miles separate the clubs' ballparks, but it's more than geography that splits their fan bases. Not even families can agree on a team.
"My husband is a Sox fan, and we live on the South Side," Cubs fan Joan McMillan said. "We have a lot of rivalry and a lot of bets at home."
The rivalry dates back to the birth of the White Sox in 1900. Owner Charles Comiskey was ready to move his minor league team from St. Paul, Minn., to Chicago and join the young American League.
This was a direct challenge to the Cubs' monopoly in the city and a territorial threat to the established National League. Yet, it wouldn't be until the 1906 World Series until the teams met on the field.
Exhibitions and charity games were the only times the clubs met until interleague play emerged in 1997. Fans have loved it ever since.
"Growing up on the South Side, you didn't really think about Cubs versus Sox a bunch other than exhibition games," White Sox fan Frank Markov said. "So it's kind of fun to watch it all happen and have it mean something. It'd be nice if they were doing a little bit better this year."
Since 1997, the White Sox have the edge, winning 49 times in their 93 meetings. The Cubs' three victories over the White Sox this season gives them their first series win since 2007.
"The one thing I forgot on our drive up is my broom," Cubs fan Derrick Campbell said. "The one thing that burns is driving up and seeing that '2005 World Series Champions' sign still up. That's going to be there forever. That hurts a little bit."