TL;DR: 

• MSI 2017 is heading to São Paulo and Rio de Janeiro, Brazil from April 28 – May 21.
• MSI 2017 will now be a 13-team tournament with representatives from all 13 LoL professional Leagues.
• Regional seed placement will be based on previous results from the past two years of MSI and Worlds.
• MSI 2017 results will continue to impact Worlds 2017 regional seeds.

Teams

At MSI 2017, 13 teams will participate across multiple stages. The recently crowned split champion (Spring Split or Split 1) from each of the following regions will participate at MSI 2017:

• Brazil (BR)
• China (CN)
• Commonwealth of Independent States (CIS)
• Europe (EU)
• Japan (JPN)
• Korea (KR)
• Latin America – North (LAN)
• Latin America – South (LAS)
• North America (NA)
• Oceania (OCE)
• Southeast Asia (SEA)
• Taiwan, Hong Kong, Macau (LMS)
• Turkey (TUR)

Seeding

This year, regions will be seeded based on previous results from the past 2 years of MSI and Worlds. We are using 2 years as our sample size for considering competitive results because:

• Within a single year, there can be considerable variance in competitive results, so we don’t want to solely rely on the most recent year of performance to determine seeding. For example, although Albus NoX Luna from CIS performed extremely well at Worlds 2016, it was their first appearance at an MSI or Worlds. We don’t believe it fair to use solely that performance to assume that CIS is stronger than LMS, who didn’t have a team make it to the Quarterfinals, but have performed well at previous events.
• On the other end of the spectrum, large structural changes have occurred globally since 2014 (for example, the division of LMS and GPL), and will continue to occur in our young sport. With this kind of rapid evolution, results from 3 years ago aren’t great indicators of current regional strength.

Once we determined the appropriate window of results to consider, we looked at all regions to compare their list of results from MSI 2015, Worlds 2015, MSI 2016, and Worlds 2016. In evaluating relative strength, we relied upon three basic principles to help distinguish similar results:

• We prioritized results at Worlds over MSI (as Worlds is the most important tournament of the year, and involves the most teams)
• We prioritized recent results over older results as a better indicator of current strength
• We evaluated tournament results by the stage achieved, regardless of opponent or game record.

Here are the aggregated results from the last two years:  

As you can see in the above graphic, LMS and NA did not perform as well as CN, EU, and KR over the last 2 years, and as a result, they will start in Play-In Stage, Round 2. Specifically: CN, EU, and KR all outperformed NA at MSI 2015, Worlds 2015, and Worlds 2016 in terms of overall standings and peak performance. CN, EU, and KR all also finished better or roughly equal to LMS at MSI 2015, Worlds 2015, and Worlds 2016.

Based on these results, #1 CN, #1 EU, and #1 KR will be auto-seeded to the Group Stage of MSI 2017, which will remain a 6-team stage.

The #1 seed from each of the following regions will start in the Play-In Stage, Round 1: BR, CIS, JPN, LAN, LAS, OCE, SEA & TUR. These regions are not being treated as a collective as they used to be – there is no more “Wildcard” status. Rather, each region’s performance is being evaluated individually, and that is what determined their 2017 event seeding and will continue to affect their seeding at future international events.

Format

Three teams will advance from the Play-In Stage to face-off against CN, EU, and KR in the Group Stage. The Group Stage will stay the same as it was in 2016 with 6 teams participating in a Best-Of 1 double round robin.

As with last year, the top four teams will advance to the Bo5 Knockout Stage.  

Implications for Worlds 2017

As with last year, the results of MSI will impact Worlds 2017 regional seeding placement.

Similar to 2016, the top regions at MSI will secure the top 4 seeds at Worlds Group Stage. Additionally, the highest ranking region of BR, CIS, JPN, LAN, LAS, OCE, SEA, and TUR will gain an additional seed at Worlds: their #1 seed will start in the Group Stage, and their new seed (the #2 seed from that region), will start in the Play-In Stage.  If two regions out of BR, CIS, JPN, LAN, LAS, OCE, SEA, and TUR finish top 4 at MSI, both of their #1 seeds will start in the Group Stage as top seeds, their #2 seeds will start in the Play-In, and the remainder of the Play-In will adjust accordingly.

Chris “RiotChopper” Hopper is one of the International Esports and League Operations Leads. His team is focused on the global development and operations of competitive League of Legends. RiotChopper is a sports fanatic who wins (almost) every Fantasy League among the Riot esports team and always cheers for his alma mater, Duke. Questions or want to chat about Magic: The Gathering? Reach out to him on Twitter via @RiotChopper.

Derrick “Riot FearGorm” Asiedu is part of our International Esports and League Operations Team. He works on the global development and operations of competitive League of Legends. He splits his time between global policy execution and implementation and supporting international events including MSI and Worlds. Riot FearGorm is jungler main and if possible, he would only play Hecarim. He used to have the most Hecarim games in the world. You can find him on Twitter at @FearGorm.