We'll be doin' some behind-the-scenes tracking of how many kills you get with each weapon by making each melee kill worth a certain amount of points. At the end of the event we'll add it all up and whoever has the most points wins the set!
We decided to nerf the point accumulation of certain melee weapons that would incentivize ONLY playing as certain classes. Not that it should stop you from playing what you like to play, just that you won't necessarily gain as many points as you would if you were playing normally. Basically if you ONLY play Demoknight, obviously you're going to gain more points than a Medic using the Ubersaw -- this is just a way to theoretically make it so every class has a chance.
Spy got hit the hardest here, only because the knife is basically their main weapon.