I have an idea about "Most Succesful Players" list. It is about total played time in server and how many killed at total count.
To see who is most succesful; There will be system about total hours played compared to kills. So when someone kills the 100 guy in a day, he will be more succesful. But when someone kills the 100 guy in a week, he will be less succesful. It sounds like ratio, but more logical and fair.