Few outsiders have visited the third floor of the Jerry Rice Building at Nike’s headquarters. Even most Nike employees know little about just what the staffers working here, on the north side of the company’s 192-acre campus in Beaverton, Ore., actually do. A sign on the main entrance reads RESTRICTED AREA: WE HEAR YOU KNOCKING, WE CAN’T LET YOU IN, and it’s only partly in jest. Inside, clusters of five or six employees huddle in side conference rooms where equations cover whiteboard walls. There are engineers and scientists with pedigrees from MIT and Apple. Leaks are tightly controlled; a public relations man jumps in front of a visitor who gazes at the computer screens for a little too long.