Reset the duel ladder annually and have an annual champions list. This will show more accurately the current talent, reward players with a permanent trophy that will never go away, and give new players a chance at making it to the top of the ladder. Currently we have old players (myself included) that have rankings that are easily preserved by not participating. This is unfair to new players and makes dueling less desired. However duels represent voluntary pvp codified.

Just including this:

Duel stats calculation has been updated (2010)

I defer this post to a much better suggestion regarding the duel system:

Run monthly duel leagues