Example: 5vs5, every player has a number (p1, p2 etc. for one team and r1, r2 etc. for another) and the corresponding numbers fight each other like that:
p1 vs r1 - p1 wins
p2 vs r2 - r2 wins
p3 vs r3 - r3 wins
p4 vs r4 - p4 wins
p5 vs r5 - p5 wins
The players who won would go to the bottom of the list and play again (p1 vs r2, p4 vs r3) until every member of one of the teams has been eliminated. So the minimum number of matches that could end the whole set is five, just like in pokemon style.