 The average number of links in the 18 chains was 5.9. But the now familiar expression, six degrees of separation, would not gain broad currency until many years later when John Guare's play by that name premiered on Broadway in 1990. The concept became a meme in full when four Albright College students introduced Six Degrees of Kevin Bacon in 1994, a game designed to measure the professional proximity of an actor, living or dead, to the American film star Kevin Bacon.