Stacker takes you inside the fiercely competitive world of sport stacking: an international individual and team sport that involves stacking specialized plastic cups in specific sequences in as little time as possible. What started as a novelty on the Johnny Carson Show in 1990 has grown to become part of school curriculums for students in over 34,000 schools in 30 countries. It's a sport that spans generations, from preschoolers to retirees, but the best of the best are 10 to 14 years old. Dive into the unique subculture of the stacking community, and find out what it's like to be a fierce competitor in an underdog sport.