On-line rating (discussion)

Added 18 minutes later
[/U]I'M CASTINGMY LINEthink about it

Rating depends on (points):
1. Number of games (obvious)
2. Opponent (strong, weak, same opponent)
3. Activity (more is better, and points are awarded for losses)
4. Acceptance or refusal of battles
5. ... (thinking)

As for casting the line, take the system from Heroes of Might and Magic and change what you don't like... or discuss this issue with players from Heroes of Might and Magic (Vigo and vitalic) – they definitely know this system and will surely give you some advice if they can't help.