I am aiming to an system which can be open for particpant to join.
What do you mean by this exactly?
Using multiple leagues sounds like a good idea
Do you mean leagues - like football teams - so you play everyone in your league twice (home and away) and the people at the top and bottom go down and up to different leagues? Those at the top of the top league fight for just being top of that league?
All trademarks or tradenames used in this Web site are the property of their respective owners. Material may not be republished, nor may content or images be mirrored on another server without written permission.