Original: It has also been said by many that Sianis put a "curse" on the Cubs, apparently preventing the team from playing in the World Series.
Simplified: Sianis became angry and cursed the Cubs, saying that they would never win a World Series as long as they played at Wrigley Field. Although the curse is often seen as a joke for most Cubs fans, some fans think it could be the reason why the Cubs have not won a World Series title.