You may fancy yourself a sports fan, but chances are you don't know: A fish eyeball was used as the center of some nineteenth-century baseballs The race to make better billiard balls led to the invention of plastics The Nerf ball was originally created to be part of a board game featuring cavemen Balls are the unsung heroes of sports. They are smacked, flung, dribbled, crushed, thrown, and kicked. They're usually only the subject of scrutiny when something goes wrong: a tear, the application of an illegal foreign substance, or a dent from overuse. Nevertheless, if you're watching nearly any major sporting event from around the world, you're likely following the ball wondering where it will go next. The Secret History of Balls mines the stories and lore of sports and recreation to offer insight into 60 balls-whether they're hollow, solid, full of air, or stuffed with twine or made of leather, metal, rubber, plastic, or polyurethane-that give us joy on playing fields and in every arena from backyards to stadiums around the globe.