All i could find was this:
"Choosing which publications and critics to include among the 35-40 in each genre is a trickier proposition, and involved a lot of careful research and study. For games and music, we attempted to identify publications that (1) were well-regarded in the industry and were known for quality reviews; (2) actually seemed to produce quality reviews (or, if not, were so influential in the industry that they had to be included); and (3) had a good quantity of reviews. We also tended to prefer publications which provided reviews online, so that our users would be able to read the complete reviews on the Internet. "
And thats just prefrences for which reviews to be included in 100 reviews score.
So i stick to what i "know". There are now "you need this amout of reviews"-limit to be apart of Metacritic.
