Riot Games posted a long response to the "MSI delay" issue

On May 10, the "League of Legends" 2022 mid-season championship was held in Busan, South Korea, and the LPL division's mid-season championship team RNG participated remotely in China. After the game, the issue of different delays in the MSI of "League of Legends" attracted people's attention, and it once ranked eighth on the Weibo hot search list. Afterward, Riot Games apologized for the delay and replay at MSI, and said it would share a detailed technical note as soon as possible.

Today, Riot officially released a super detailed technical description of more than 8,000 words. The following is an overview of Riot’s response:

Over the past few days, the Riot Games esports tech team has been working through a number of technical issues surrounding the 2022 Mid-Season Championship, especially with the tools we use to balance pings for both offline and remote players.

The problem we first discovered was a bug in what we called the "Latency Service Tool" - this tool was used to adjust the latency (ping) of all competitors to the 35ms range, and this The players in the game have additional delays during the game and make their actual delays higher than the delays displayed on the computer screen on the venue (35ms). So, in remote matches, players in China are playing in the 35ms ping range, but players in Busan have higher pings. Unfortunately, we didn't find this issue before the MSI started, and the root cause was a bug in the code that miscalculated the delay, causing the value to be incorrect in the logs as well. So even though our monitoring shows that everything is fine, there is actually something wrong.

We made a configuration change to the delayed service tool on May 13 to address this vulnerability. Considering the impact of previous increases in actual network latency on games in the Busan stadium, we made the difficult but necessary decision: replay the three games with different pings in Group B.

However, another problem with this configuration change on May 13th is that the Busan player's computer screen is now showing an incorrect, lower number than the actual ping - although the actual ping has now been corrected and ensured equal. As a consequence, when we played the player screen, an incorrectly low ping value was displayed on the screen. At the same time, because our team failed to effectively communicate this apparent error in a timely manner, the audience would think that the players in the arena were playing at a lower ping than their actual latency.