Richard hasn't published the formula for the rating system for any of the games, but he has said that behind the scenes the go ratings use the same system as everything else. To all appearances that system is somthing similar to Glicko, which could be considered a variant of Elo. You could look up Glicko and Elo in Google.
Based on the way the Rating Tournaments are set up, I believe that 1 kyu (or dan) level equals 50 points in the other games.
