alanback: FIBS uses a backgammon formula which is used on many sites. Like the chess formula that is used here, it encapsulates the entire playing history. The 400 figure that you're remembering is used when a new player is establishing their rating. For the first 400 experience points the amount gained or lost by a match is multiplied by a number proportional to how many of the 400 points are left. The multiple is 5 at the start and 1 by the time the player has reached 400.

I also don't care to see the same 6/0/0 at the top of the rankings table. Perhaps the cocktail has lost his bottle? I like pgt's suggestion of using a limited history but it might be expensive to administer. A reasonably easy to write method would be that the ratings are recalculated every day for every player (and presumably for every game type). I don't know how much server time that would take but it would certainly be a growing amount as the site gains in popularity. Doing it monthly would be a reasonable compromise; a different set of players could be done on each day of the month.