Based at what time of the day you play, it is predictable what the matchmaker will do.
Middle of the day: You will only get idiotic players in your team, and are placed against uber players. You will have cheese team matchups and tanks infect Deathmatch.
In the evening, when the kids are in bed: Better matches overall. People know the unwritten rules and people go toe to toe.
At night: Drunk people.
(Early mornings are just empty)
Matchmaker just does not base balanced matchmaking on skill, because matchmaking times never change, but the quality of the matches varies severily.
