The current matchmaking system uses a modified version of TrueSkill™ ranking system.Around December, there was a feature added that allowed players to choose between US and EU servers, but was later removed from the game due to issues with the matchmaking system. The region lock feature was eventually re-added. Most modes operate on queues with 3-minute match-making timers. Every three minutes, matches will be made from the group of people in queue at that time. This helps optimize match-making.