Bacon number

Kevin Bacon is well known for a college movie trivia game called Six Degrees of Kevin Bacon, which is intended to find the Bacon number of an arbitrary actor or actress. The Bacon number of an actor or actress is determined as follows:

• Kevin Bacon has a Bacon number of zero.
• The Bacon number of actor or actress A is defined to be the minimum of the Bacon numbers of all the actors or actresses with whom A appeared in a movie produced by a major studio, plus one. The most common source used to determine whether or not a film is valid is whether or not it is present on the Internet Movie Database.

By this definition, there is at least one IMDb actor with an infinite Bacon number, Fred Ott[?]. He acted in only two films and is the only actor in each of them, disproving the Theory of Six Degrees of Kevin Bacon that everyone who has ever appeared in any movie has a finite Bacon number. (Thomas Edison would be another example, if you count his appearance in a film).

However, the majority of actors do have a Bacon number of 2 or 3. The higher the Bacon number of an actor, the less connected they are to other actors. Using the actor with the highest known finite Bacon number (10), William Rufus Shafter as the centre of the acting universe instead of Bacon, we can find seven actors with a Rufus Shafter number of 16.

The Bacon number is an application of the same idea as the Erdos number in Mathematics to the movie industry. Remarkably, Paul Erdos himself has a Bacon number of 4, due to his appearance as himself in the 1993 film N Is a Number.

Notably, Bacon is not the most linkable actor (he is the 1161st most linkable actor). That honour goes to Christopher Lee, with 99.991% of movie actors having a Lee number <= 6 (not counting those with Lee numbers of infinity). By comparison, only 99.975% of movie actors have a Bacon number <= 6.

Actors with record largest finite Bacon number by year

Year		Record
1996		7
1997		7
1998		all 7s
1999		8
2000		all 8s
Dec 2000		9, 10

But note: according to the Oracle of Bacon at Virginia,

"About 12% of all actors cannot be linked to the rest of the movie universe, either because they have appeared only in TV features or straight-to-video releases that the Oracle doesn't count, or because they have not appeared in any features with actors from the Hollywood mainstream."

Links:

• The Oracle of Bacon at Virginia (http://www.cs.virginia.edu/oracle/) computes the Bacon number of any actor or actress from IMDb data