MrNomNom said:
In order for the ranking system to make sense, everyone has to duel everyone the same amount of times. If someone is challenged by not so skilled dueler over and over, then their score is skewed. I don't know about scheduling for the ladder as well.
I might have solutions for both issues. The rough idea is to use the ELO rating (commonly used in chess) as proposed by CommissarK (?) a few months ago (but the project never seemed to take off). The idea of the rating is that the bigger the rating difference is the more points does the "underdog" get in the event that he/she wins the challenge. This makes attaining the "true" rating rather fast.
The responsiveness to challenges was a big issue in NASTe and something any ladder should address. One solution would be to put a maximum period of response to a challenge after which the duelist being challenged gets kicked out of the ladder. But, I think, the less abrupt and more interesting method would be to decrease the rating of the responder exponentially (first slowly, then very fast) once a challenge has been issued, so that the rating halves after the challenge hasn't been responded to in, say, 14 days.
Of course, these are just rough ideas and the general system and the specific numbers need work.