 In fact, All-High Stadium has only a single level of stands with a roof.The upper deck in the film appears to have been inserted in post-production, and the scoreboard either matted in or built as a temporary structure over an existing tall smokestack on a building that stands at the north corner of the stadium, presumably part of Bennett High's heating plant.The actual Wrigley does not have smokestacks, but rather houses and small businesses serving as its backdrops.