It was only a matter of time, of course. Mathematicians have the Erdőz number, actors have the Bacon number, Go players have the Shusaku number and now Jeff Rients have taken the logical step and invented the "Gygax number" for measuring how connected you are to the late Gary Gygax.
Gygax himself would have a Gygax number of 0, anyone who played in a game with him has a Gygax number of 1, anyone who played with any of them (but not with Gygax himself) has a number of 2. Rients is better at explaining than me. Really.
My own Gygax number? Dunno, probably pretty high since I've never gamed with Americans face-to-face.