It's A Small World

Many people, in one context or another, are familiar with the "small world" phenomenon. You're sitting next to a stranger on an airplane, at a large party, or at a ball game and after talking a bit you realize that one of your relatives knows the sister of the stranger's best friend-in fact they work for the same company. Such a connection leads you to remark "Guess it's a small world huh?" Movie buffs might be familiar with the Kevin Bacon Game in which an actor is selected at random (or because he or she is a favorite) and we see how few links are needed to connect him or her to Kevin Bacon.

In this case,"connecting" means establishing links of the kind:"appeared in a movie with." The number of links needed to make the connection is the actor's Kevin Bacon Number (KBN). For example, Jodie Foster's KBN is 2 because Jodie Foster appeared in Five Corners with Tim Robbins, and Tim Robbins appeared in Mystic River with Kevin Bacon. So two links (or movies) are needed to get from Kevin Bacon to Jodie Foster.