Random Number Generator + Pokemon Showdown? Genuis.

Using RANDOM.org, a number out of 18 is selected. Then, using Bulbapedia's pokemon type listing page, the type for your gym is detirmined. After all teams are complete, everyone battles each other. 1 point for victory, 2 points if you defeat someone who has a type advantage, .5 for beating someone with a type disadvantage. Person with the most points at the end wins!

Random Number Generator: http://www.random.org/
Bulbapedia Types: http://bulbapedia.bulbagarden.net/wiki/Type

Current Types:
Sean Murphy: Water
Michael Mueller: Grass
Chris Kee: Dark
Evan Boyd: Ice
Noah Barry: Steel
Gigi Getty: Ghost
Daniel Maksimik: Normal
Colin Boyd: Bug