alanback: you mean a combined rating would calculate all games in all subtypes as 1 total rating ? so when i play a game of nackgammon it would calculate into my nackgammon rating and also into my average combined gammon rating ? if i play a game of hyper gammon it would calculate into my hyper rating .. and also into my combined rating ?

that would be a better 'average' indeed :)

the list posted below could show something different as well if calculated as a combined rating .. we mere mortals cant that though .. the formula would have to be run through the whole data set as it was done with the last change in the rating formula .. that means quite some more work than just an averaging .. but would be much more accurate :)