excellent idea of multiple sections. In your example the sections would take 19 rounds at most, the final of only 13 people would take only 12 rounds.
I would suggest you keep your totals throughout the tournament as well.
In the hypothetical version where you get only 30 points, is there still a 500 point bonus? Or would it always be 1/40 of the starting total? Or would it depend on the number of players?
(hide) If you are waiting for your turn, click on "change" next to the "refresh" on the main page, then set refresh the page to 30 seconds to get your turn to move displayed faster. (Servant) (show all tips)