Well, the only one I can come up with, which does not want players to commit suicide is:(posted 8949 days ago)level reached*10000 + levels won*1000
This might mean that some players end up with the same score, but so what? This method also means that you have to fight to get as fare as possible scoring as many points in each round as possible.
I might be wrong, but why not keep it simple.
The chance of two players getting to the same level getting the same score is not that big I think.
Let's keep it simple :-)
Bye.