The most popular outdoor basketball court in New York City is half the regulation size, offers no seating, and has sidelines bounded by a chain-link fence. But the summer league on West 4th Street in Greenwich Village has developed its share of stars and has become known throughout the world for another reason: Here the only thing that matters is the game.

Inside the Cage follows the West 4th Street's summer league through a single season, chronicling its legendary history along the way. From 1970s playground legend Fly Williams to NBA veteran Anthony Mason and L.A. Lakers guard...