I ran across this interesting interview with Mark “Smiley” Glickman. He discusses the Glicko and Glicko-2 rating systems which are based on dynamic Bayesian models. From a statistical perspective, some of the most interesting discussion comes near the middle of the interview where he discusses the chess federation’s ongoing project to monitor average ratings, and the challenge of comparing ratings of people in different years. The bit at the very end is also interesting–it reminds me of the claim I once heard that a chess player, if given the option of being a better player or having a higher rating, would choose the higher rating. One of the difficulties of numerical ratings or rankings is that people can take them too seriously, and Glickman discusses this.