Hrqls: That's a good idea. They do that at Vog for one of their tourney types. It's done as the percentage of the track that you succeeded on, so the winner gets 100%. The percentage for the rest depends on the number of rounds. A semi-finalist in a 4 round tourney will get 75% (25% for each of the three wins), a 2nd rounder in a 5-round tourney gets 20%, etc. As there are automatic byes you can still pick up points even if you lost your first (but 2nd round) match. It's not a flawless system by any means but it does add to the competition.

That points for tourneys. A rating for tourney play would be the average position (percentage0 reached. Over 50% is good, while 70% is phenomenal.