You wonder how this Ranking-Table was generated? Each first rank in a single game gets you so many points as there are registered users.
Second rank one point less and so on. All these points get added and so the all-over-highscoretable will be generated.
But after 60 days all single Highscores will be deleted from database - so all gamblers will get the chance to come into top ten. Do not rest on your laurels rest and try to get better scores each time (this function is enabled in later versions)