Isn't there a book on this subject and Bacon does the forward?
Wow, this is in depth.
en.wikipedia.org/wiki/Six_Degrees_of_Kevin_BaconThe Bacon number of an actor is the number of degrees of separation he or she has from Bacon, as defined by the game. This is an application of the Erdős number concept to the Hollywood movie industry. The higher the Bacon number, the greater the separation from Kevin Bacon the actor is.
The computation of a Bacon number for actor X is a "shortest path" algorithm, applied to the co-stardom network:
Kevin Bacon himself has a Bacon number of 0.
Those actors who have worked directly with Kevin Bacon have a Bacon number of 1.
If the lowest Bacon number of any actor with whom X has appeared in any movie is N, X's Bacon number is N+1.
Examples
Elvis Presley:
Elvis Presley was in Change of Habit (1969) with Edward Asner
Edward Asner was in JFK (1991) with Kevin Bacon
Therefore, Asner has a Bacon number of 1, and Presley (who never appeared in a film with Bacon) has a Bacon number of 2.
Ian McKellen:
Ian McKellen was in X-Men: Days of Future Past (2014) with Michael Fassbender and James McAvoy
McAvoy and Fassbender were in X-Men: First Class (2011) with Kevin Bacon
Therefore, McAvoy and Fassbender have Bacon numbers of 1, and McKellen has a Bacon number of 2.
Because some people have both a finite Bacon and a finite Erdős number because of acting and publications, there are a rare few who have a finite Erdős–Bacon number, which is defined as the sum of a person's independent Erdős and Bacon numbers.
