The Worlds 2018 Draw Show will air on Sunday, September 23 at 5:00 AM PT (9:00 PM local time in Korea).

The Worlds Draw Show is the process by which teams are placed into groups for the Play-In Stage and the Group Stage of the 2018 World Championship. We’ll be holding draws for both stages, one after the other, according to the rules and structure described below. This post is designed to give you a solid understanding of the mechanics of the draw process and a clear idea of what to expect during the live draws.

How does the Play-In Draw work?

Twelve teams have been placed into three Draw Pools based on past regional performance. During the Draw Show, these three pools will be sorted into competition groups for the tournament.

We used the last two years of competitive results, including MSI 2017 and 2018 and Worlds 2017, to determine the Draw Pools. 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 Play-In Draw seeding results:

Play-In Draw Rules

• Each group must have exactly one team from Pool 1
• Each group must have exactly one team from Pool 2
• Each group must have exactly one team from Pool 3

Procedure

The draw process will start by drawing all four teams from Pool 1 into different groups. Then, we’ll draw one team from Pool 2 into each group, and finally one team from Pool 3 into each group.

How does the Group Draw work?

Sixteen teams will be been placed into three Draw Pools based on their 2018 performance. During the Draw Show, these three pools will be sorted into competition groups for the tournament.

*The Number 1 Seeds shown in Pool 1 are determined solely by the top-four finishing regions at MSI, which this year were LPL (China), LCK (Korea), EU LCS (Europe) and LMS (Taiwan, Hong Kong, and Macau).

Group Draw Rules

• No group can have more than one team from the same region. So, for example, #1 CN and #2 CN cannot inhabit the same group.
• Each group must have exactly one team from Pool 1
• Each group must have exactly two teams from Pool 2
• Each group must have exactly one team that qualifies from the Play-In Stage

Procedure

The draw begins with the seeds physically separated into two bowls by Pool. The groups are arranged in alphabetical order from left to right – A, B, C, and D. First, all of the seeds from Pool 1 are drawn randomly and then Pool 2. The Play-In teams will be drawn into the already existing groups after the final Play-In Elimination game on October 7. 

When a seed is drawn, it is placed into the next group available in alphabetical order so long as that would not render the draw invalid at any future point by preventing another seed from being placed in a valid spot. For example, if placing the next drawn seed into Group A would make it impossible to place a future seed without violating a rule, that seed would need to “skip” Group A and be placed in B, C, or D, depending on what spot is available – more on this later.

In Pool 2, each group must have one Pool 2 seed before any group has two Pool 2 seeds, unless doing so would create an invalid draw.

For example, imagine #2 CN has just been drawn as the first team from Pool 2, but #1 CN already occupies Group A. Because of rule #1 (no group can have more than one team from the same region), #2 CN cannot occupy Group A, and is placed in the next available group, Group B, which currently has space for Pool 2 teams and has no CN seeds.

Invalid Draws

Because seeds are drawn randomly and there are several rules governing where those seeds can go, there are a few situations we can run into in which a draw cannot be completed, rendering the draw “invalid”. The general procedure for avoiding invalid draws is the same year to year, although the scenarios in which invalid draws can arise varies depending on which seeds are in which pool every year. Below is an example specific to 2018.

In the above example, there are two Pool 3 spots remaining (in Group C and D), two Pool 3 seeds that need to fill those spots (#3 EU and #3 NA), but #3 NA can’t go into either Group C or Group D because both Group C and Group D each have an NA team, so another NA seed cannot inhabit that group.

There are two ways to deal with situations like this. One would be to simply restart the draft until we avoid an invalid draw, but this could result in an infinite number of restarts and, since the show is live, isn’t realistic.

Alternatively, we could monitor the draw as it proceeds, and use a series of logical checks to identify when placement of a specific team would create an invalid draw down the road. If that happens (specifically before picks 9, 10, 11, 13, 14, and 15), we can move the team to the first available placement that would avoid the invalid draw.

To see an example of how one such check would work, let’s revisit the invalid draw example pictured above. In that example, we’re already at a point where the draw cannot be resolved. The problem arose when #3 CN was drawn – when #3 CN was placed into Group B (despite being a valid placement), that left a team (#3 NA) that could not fit in either available slot in either Group C or Group D.

However, if we rewind to before Pick 14 (when #3 CN was drawn), we can see that it’s possible to anticipate and prevent this by placing #3 CN in a spot that would not create an invalid draw further along in the draft. What follows is the logic for deducing where #3 CN must go when drawn at Pick 14.

In this example, exactly one CN, one NA team and one EU team remain. There are two potential groups for CN (Group B and Group C), two potential groups for EU (Group C and Group D) and one possible spot for NA (Group B). 

To avoid putting ourselves in an invalid draw, if the 14th overall pick is a CN team, it must go to Group C because any other placement would create an invalid draw. Likewise, when picked, the NA team would have to be placed in Group B and the EU team would go to Group D.

These kinds of checks ensure that the draw can proceed without the need to restart and will stay in compliance with the rules of the draw.

That should be all you need to know about the Worlds 2018 Draw Show. To see how the groups turn out, tune in to lolesports.com on September 23 at 5:00 AM PT.