Hey everyone, Ed “SapMagic” Altorfer here on behalf of the Ranked team. Earlier today, we dug into a few position rank-specific bugs that could affect the quality of matches in **North America** and **Korea**. In this post, I want to detail the issues we’re seeing and what we’re doing to fix them.
#MMR Linking and LP Updates for Position Swapping
We found a couple bugs that affect how we handle position swapping and could lead to diminished match quality or incorrect LP updates in certain situations.
##Issue: The links between MMRs are not tightening correctly for high-skill players.
We talked in [/dev: Addressing Your Feedback on Ranked for 2019](https://nexus.leagueoflegends.com/en-us/2018/06/dev-addressing-your-feedback-on-ranked-for-2019/) about how, behind the scenes, we link your position MMRs together. We tighten those links the more you swap positions to prevent abuse or when you’re close to Master Tier where you have a single rank.
In our investigation, we found the link tightening wasn’t responsive enough for high-skill players. As a result, players who position swapped at Diamond+ found themselves in much easier matches than we intended.
**Conclusion:** We have fixed this bug for both North America and Korea as of **today, January 31 at 2:00 PM GMT-8**.
While some players were able to abuse this bug, we want to avoid solutions like resetting the Master+ ladder, which would punish the vast majority of players who earned their LP legitimately. Instead, now that we’ve fixed the issue, players who took advantage of it will get harder matches regardless of swapping, and their ranks will recalibrate as they lose games. We will monitor closely and make additional changes if needed.
We thought there was a possibility we could run into issues like this, so we preemptively locked Grandmaster and Challenger for the first few weeks of the season to ensure we could make fixes and respond to player feedback.
##Issue: Some players may not receive properly diminished LP gains when they swap positions.
The issue above should’ve been mitigated by another detection system which determines when you swap positions and adjusts your LP accordingly. When you swap into a slightly easier game before link tightening has kicked in, you _should_ get significantly less LP and have larger LP losses. While the actual position **detection** is working, it isn’t being taken into account in some cases when determining LP gains for the match.
**Conclusion:** Patching the previous bug should prevent the vast majority of cases where this logic is necessary, but we still believe adjusting LP like this is an important fallback for situations where—as we discovered today—MMR linking doesn’t work as intended.
~~We’re aiming to roll out a fix for this one before the weekend, within the next **24–48 hours**~~ We fixed this bug on **February 1 at 9:00 PM GMT-8**.
#Correctness of Match Data on Third Party Sites
With the introduction of position ranks, new information is necessary for third party sites to show all the right ranks. We’ve found some issues with the data we’re providing which can lead to inaccurate match details.
##Issue: Some players are displayed as Master when they aren’t and vice versa.
Due to a problem with the underlying tech we’re using to calculate and track rank information we’re sending to the Riot API, we were giving third party sites incorrect data.
**Conclusion:** We fixed this bug **yesterday, January 30 at 5:00 PM GMT-8**, so players should be able to see who’s actually Master Tier and who’s not on third party sites.
##Issue: Some matches may display the incorrect ranks for position played.
With position ranks, displaying the ranks for an individual game got a little trickier. Third party sites will eventually be able to display the ranks for each player’s position played, but we don’t currently provide the right information for them to do so.
**Conclusion:** We’re collaborating with the Riot API team and third party sites to provide them accurate data as soon as possible. Once a fix goes out, you’ll be able to rely on the ranks shown for matches again.
We’ll update this post with an ETA after we’ve resolved the other issues.
These bugs are painful to say the least, but on behalf of the team, thank you for helping us find and fix them as quickly as possible. If you’re seeing other issues that aren’t captured here or you just have feedback about the system, let us know in the comments. Thanks for all your help, and we’ll see you on the Rift.