alanback: I think you're right about the compression. In fact, because the points awarded favour the lower player so greatly, I believe it'll be over-compressed.

Playing all and sundry in single-pointer tourney matches is going to kill the ratings of the higher players who join a lot of them. (Score one for the Knights vs the Rooks, for a change, lol). Winning 60-65% of tourney matches, as a top player would, will not be enough compensation for the 7 to 1 points differential against players within 300 points and certainly not for the 15 : 1 against those further down.

After the adjustment all those games which previously won 8 useful points will only, in fact, have earned beans while the lost matches will be harshly felt.

Another aspect of this formula is that the ranking system will be highly volatile. A player rated 120 below will have a 2 : 1 advantage in the points awarded though the skill differential is minor and the luck differential is zero. Any player to reach a height can be tumbled merely by winning 50-50 against weaker players.