Metacritic system compromise with calculations. Halo 4 really is at 90% not 87%

[theRepublic]

This has probably already been mentioned, but Metacritic does not use a standard average for its final score. It uses a weighted average. Some sites affect the score more than others. So the little dinky sites that are more likely to give crazy review scores are counted less in the overall score than the bigger, more respected* sites.

*I use this term loosely. This is video game journalism after all.