Does anyone know exactly how the rating system works?

lol not a clue

In English, if a player is playing somebody of equal strength, he will gain 16 points with a win, lose 16 points with a loss, and gain nothing with a draw.  For every 25 rating points higher that your opponent has than you, he will get one point less than 16 for a win, lose 17 for a loss, and lose a point for drawing.  You always get at least two points for winning though.  (ELO)  Glicko is much more complicated.  I can't explain it.

For more information on the ratings at Chess.com you should read http://www.chess.com/article/view/chess-ratings---how-they-work