Another idea, just to help for the humans
When a team win the game, the other team gets a "reward"
So:
we win this round --> In the next round the humans decrease with three (-3)
we win the next round --> "-4" for the humans.
then the humans win --> just "-3" for them
then they win again --> "-2"
again --> "-1" (so -1 for the humans; +1 for the elves)
they win again --> +2 for us, -1 for them
[...]
I hope you understand me
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