Update from the team working on the fix: http://boards.na.leagueoflegends.com/en/c/developer-corner/7i1WBYXy-update-on-preseason-ranked
If you've been playing Ranked or reading the Boards you may have noticed some wild changes in placement rankings after this morning. This is the result of a fix that went out this morning to correct all the previously wild placement results and matchmaking that was going on until now.
We've made changes to OCE first, because it was the first region to release Ranked Flex. These changes were aimed at correcting MMR problems that originated from issues with Ranked Flex's launch. These problems with everyone's MMR have caused most players to be incorrectly placed after their provisional games, and created issues that led to very poor matchmaking and inflated LP gains.
After the changes this morning everyone who completed their placements will have to play one more game to be correctly placed.
**So did the fix work?**
Since this morning we've monitored the effects on player MMR and which leagues players were being placed into, and saw that players were looking much closer to their actual ratings. Unfortunately, for players who have climbed ranks rapidly as a result of incorrect placement and inflated LP gains, this correction to their actual rank feels punishing. We know some players were stoked to be climbing higher and faster than they ever have but it’s pretty likely that the matchmaking for those players was a bit of a clown fiesta in the first place, and that their placements and LP gains were largely inflated.
Ultimately, for ranked to be as competitive as possible, we wanted to make sure they (and their opponents) had a fair climb up the ladder and this means resetting everyone to their correct rank. Although for some players, this also means being placed higher after today as their incorrect MMR had identified them as lower than their true rank.