The team behind a new achievement tracking website called TrueAchievements is very, very angry. The reason: Achievements and their Gamerscore aren't really standardized, meaning that Gamerscore isn't a true depiction of a person's gaming talent. So, TrueAchievements did something about their frustrations.
Based on the idea that the harder an achievement is to unlock -- no matter its Gamerscore value -- the more points it should be worth. Using a formula that takes into account how many players unlocked a specific achievement compared to the game's total population, a difficulty multiplier is calculated. The multiplier is figured into the game's Gamerscore and, presto! A new, more accurate way to calculate a person's skill has been developed.