This began in the 1940s atop the manually operated scoreboard out in center field. The white flag with a “W” would be raised on the left side (looking from home plate) after the Cubs won a game. The “W” clearly coming from the word “win,” earning it the name “Cubs Win Flag.” When the Cubs lost, a blue flag with a white “L” was flown on the right side. This was to alert the and riders of the elevated-train about the outcome of the game. If you fly the Cubs’ W flag and are curious about how long you should leave it up,the Cubs’ ballpark operations team says the flag is typically taken down during the next day’s morning commute. Though as the Cubs have won games and gone on runs that could potentially end the World Series drought, fans have hung the flag during playoff runs regardless of whether they’ve won or loss as a sense of pride. Inside the stadium, fans typically hold off on pulling them out until they’ve won the game and fans begin to sing “Go Cubs Go.”