We are aware of the issues with match quality and odd placements in Ranked Flex. We have put a short term fix in place that should fix some but not all players MMRs. Unfortunately, to fix all players' MMRs and correct the issue that's causing players to be seeded incorrectly, we will require some downtime.
We are working through the best way to roll this fix out and you can expect additional details in the coming week. Thank you for your continued patience!
A lot of you had to play one placement match today. This was due to a fix going out this morning.
Network Operations – 8:14 AM
We have rolled out a potential fix for the matchmaking issues in Ranked. If you have already placed into a League, you will need to play one additional placement game to determine your new ranking
You can now find a more detailed explanation [here](http://boards.oce.leagueoflegends.com/en/c/announcements/XMZm8OPI-ranked-corrections-to-placement-results-and-ranks).
Latest update here - http://boards.oce.leagueoflegends.com/en/c/announcements/XMZm8OPI-ranked-corrections-to-placement-results-and-ranks