Does anyone know hoe familiarity is caclulated, as in how may games back does it go?
I paid attention closely to this during the beta overlay... I believe the same mechanics are in place. They appeared to start collecting familiarity data when the overlay went live. I started out with 0% to people in my premade, and that number grew after several games. I'm guessing its a new data stream that they are tracking and didn't think it would be worth it or possible to grab older stats (not really a big deal IMO anyway).
Also, I think the entire Aussie community is going to start looking like one big premade (lolz). At least in the beta, it didn't matter if you were on the same team as everyone - familiarity % would increase if a player was simply in the same game as you.