rednaz23: That had me puzzled for some time too. That different games have different rating scales is absolutely normal, those depend on the skill differences (new games have few experts) and the "skill factor" of the game (a very skillful - and long - game will have bigger rating differences). But the average rating of all players should remain approximatively equal to the entry rating (1400 if I remember correctly).

What happens in backgammon is probably that many players have hundreds of started games when they suddenly leave the site and lose all games on time. As a result they fall to a ridiculous rating, but this rating disappears from the lists because they are not active any more. An average on all players, including the inactive ones, should be much closer to 1400 than the average you see on the ranking lists.

The ratings would be more realistic if they were shifted from time to time to center them around the 1400 value. But it is not really required if you keep in mind that absolute ratings do not necessarily have any meaning, only rating differences have.

wetware : It is not correct that rating differences are capped to 400 in the USCF=BK system.