RANK() emulator?

[Maxime Michel]

I will be running a site with a Flash game, that will send data to a PHP script that will then send it to the database. Let's say my game has 500 levels. There will also be new levels every few days. I plan the userbase to be around 20,000 people, for a start.

I want to keep the highscore of everyone on each of these levels. So Person1 would have up to 500 scores in the db. I would then access those scores from different PHP scripts. There would be a page for the best score on each level, a page showing Person1 best scores for all levels, and probably other things in the future.

I was thinking making one huge table with all the scores instead of splitting them by levels (which would make over 500 tables).

My problem is the following: how can I know the rank of a person score? Let's say I have the columns User, Level and Score. If I wanted to know the rank of Dummy in level "Alpha", how would I do it?