 The championships banners have been replaced by small pennants that fly on masts at the back of the left field upper deck.Those pennants, along with the flags flying in the plaza behind right field, serve as a visual cue for the players, suggesting the wind direction and speed.Jackie Robinson's number, 42, was retired by Major League Baseball on April 15, 1997 and formally honored by the Twins on May 23, 1997.