Your score will now be determined by various factors some even outside the game.
Prime was a system presented by Valve a year ago that improved the matchmaking for Counter-Strike: Global Offensive but now a new system called Trust enters the fray.
“What if the Prime system was re-imagined using a wider range of factors? We started with that question, and have been experimenting with matching players using observed behaviors and attributes of their Steam account, including the overall amount of time they had spent playing CS: GO, how frequently they were reported for cheating, time spent playing other games on their Steam account, etc. We call this system Trust, and these factors considered together form a player’s Trust Factor.”
It’s all good and well, however, Valve doesn’t want to reveal how your “Trust factor” is calculated.
“We’re still iterating on the Trust Factor model and adjusting the way various factors are combined, but we want to make sure that all you have to do to improve your matchmaking experience is continue to play CS: GO and other Steam games legitimately. The more you play, the more information the system has and the easier it will be for the system to determine who you should be matched with.”
If you somehow felt mistreated by the new system you can still use Prime or drop an email to CSGOTeamFeedback@valvesoftware.com for some clarification.