But your opponent might learn somethingI understand your English, do not worry about that ;)
You say that there should be levels? For example:
Level 1 - Weak fighters/noobs
...
...
...
...
Level 10 - Best fighters
If this is so, I do not like your idea. For example:
You are Level 3 and you have to fight against someone of Level 7 and you lose, then you learn something. Tactics, for example.
If you are fighting against someone of your own level, you do not learn something :)