The Braves have been working all year for this weekend. “We are going to blow this place up,” Scott Cunningham, VP of fan experience for the team, says of Truist Park. “It’s going to be incredible.”

Atlanta is among the Major League Baseball clubs unleashing huge postgame pyrotechnics shows for America’s 250th birthday. For months, team executives like Cunningham have been planning their July 4 weekend displays, which will send fireworks bursting over 14 MLB stadiums—most as bigger-than-usual productions.

While fans take in the entertainment, they’ll also be watching the culmination of a sometimes-grueling effort that is as technical and tactical as it is theatrical.

MLB clubs and pyrotechnics companies tell Front Office Sports that before the first shell streaks the sky on July 4 weekend—or any other night of the season—they’ve spent untold hours sourcing fireworks, mapping launch locations, coordinating with public safety officials, and meticulously designing themed shows timed to music. The spectacle itself may last less than 10 minutes, but getting there is a year-round operation.

Baseball’s postgame pyrotechnics shows largely began as a marketing ploy to fill minor league stadiums for special occasions. They have since evolved into one of the sport’s signature experiences—as important to fans as it is to franchises looking to fill seats.