A persons Erdős Number is the "collaborative distance" to mathematician Paul Erdős, as measured by authorship of (scientific) papers. Ones Erdos number can be calculated using the MathSciNet Erdos number calculator.

My Erdos number is at least as low as 6, as I have published with Jorgen Randrup, who has an Erdos number of 5. However, as Sheldon Lee Glashow has an Erdos number of 2, I suspect that my minimal number is 4, given that someone in the BABAR or ATLAS collaboration almost surely has published something with him. However, I have not found concrete example, yet.

A persons Bacon Number is defined in the same way, as the Erdos number, however linking people by movies.

My Bacon number is 3, as Kevin Bacon was in

A person may have a finite Erdős-Bacon Number, which is defined as the addition of their Erdos and their Bacon number. It requires that one has participated in a movie AND published a scientific article, which is a bit rare.

In chess one uses the Morphy Number, named after chess player Paul Morphy (1837-1884). Due to the length of time since his death, most professional players have a Morphy number of 5. The former world champion Garry Kasparov has a Morphy number of 4, and as I have played Benjamin Koppel, who played him, mine is 6.