WhiteTower: I have discovered that my ratings in the 4 backgammon games mentioned are very close, except for regular backgammon where ratings are higher for some reason -- possibly just because more games have been played, possibly because the makeup of the player pool is different. But when I played backgammon and nackgammon under separate names on a different server, I found the ratings were so close that I decided to give up the idea of separate accounts for different games. I think the 4 games mentioned have essentially the same strategy, and there would be no harm in computing a single rating for all 4. The question, of course, is whether it is meaningful to combine the ratings (you probably wouldn't want to combine backgammon with chess), and I think that it is meaningful to combine those 4 games. With due respect to my carrot-loving and procreative furry friend, I think that Hypergammon and Anti-backgammon are sufficiently different from the 4 I play to make them truly different games, and to make a combined rating less informative than separate ratings.