It's a rating system that was created by a Professor Mark Glickman that looks to address deficiencies in the Elo rating system. Most importantly, the fact that there are occasions where the ratings of two players playing against each other may not take into account the actual strengths of the players and their ratings may be arbitrary. For more info:
http://math.bu.edu/people/mg/glicko/glicko.doc/glicko.html
Basically RD is a measure of how likely your rating is to be true.
RD stands for Rating Deviation. If you are new to the site (or wherever), then you are P for provisional. As you play more, your RD goes down, and your actual rating becomes more accurate.
Then, let's say you take a few months off and travel the world. When you come back, the Glicko system will put you at E, for estimated. The same rule applies; you must get your RD back down below 80 in order for it to be objectively accurate.
:)
What does 'Glicko RD' means ? Can anyone tell me please