Matchmaking bugged?

[lordbeckett21]

I have experienced a recent change to how my matches have been progressing. I used to win and lose matches at pretty much even rates. After I ranked down from Oracle I to Archon VI, the quality of matches absolutely plummeted.

Here's my match history before everything went to shit:


Here it is after the rank down (these are my most recent matches):


What the hell happened?