The Bacon number is to movie actors what the Erdős number is to mathematicians, only the connections are through films, and the central actor to connect to is Kevin Bacon. Because of the play Six Degrees of Separation
, the common wisdom held that most actors could be linked in six steps. In fact, for most actors working today, whether in Hollywood, Bollywood, or anywhere in the world, can be connected to Bacon in just two steps. Even actors from the black and white era can be connected to Bacon in as short as three steps. For example, Nikolai Cherkasov (of Alexander Nevsky fame) was in Nights of Farewell with Jacques Ferriere, who was in Le Chainon manquant with Bill Murray, who was in Wild Things with Kevin Bacon.