The sound comes from a Ken Griffey Jr. baseball game on Nintendo 64, where a grand slam triggers a loud stadium reaction and excited in-game commentary. Long after the console era ended, the clip survived through user-generated soundboards, where fans clipped the most satisfying moment for reuse outside the game. It still works because a grand slam is a universal sports shorthand for a sudden, game-changing win, and the short burst of crowd noise makes that feeling immediate even for viewers who never played the original game.