My first project on this blog is to bring an Elo ranking to the Overwatch League.

So what is Elo? At a high level it is a way to rate opponents in head-to-head competition. If you play a lot of multiplayer games, it is probably most akin to MMR (and elements of Elo are likely used in MMR calculations). The only thing that matters is the result & the chance of that result. For example, Seoul would gain more if it beat NYXL (both undefeated) compared to beating Shanghai (0-4). Of course the same is true in reverse, if Seoul lost to Shanghai their rating would take a massive hit.

I hope to go into more detail in the future how I have attempted to calculate Elo for OWL, but for now without further ado here is the rankings after Week 2:

Overwatch League Elo

So what is this telling us? Lets highlight a few points.

Elo largely matches the Blizzard’s rankings

Not surprising, but the Elo rankings largely matches the ranking from Blizzard (noted as ‘Rank’). The exceptions are the two LA teams. Valiant benefits from a larger k-factor in week 1 in an attempt jump-start the rankings. Gladiators has the same W-L record as SF Shock & Philadelphia Fusion, but have had a tougher schedule to start. Both will be tested this week as they face each other & other 2-2 teams.

Tiers begin to emerge

Through week 2, there seems to be some clustering in team power. At the top are the undefeated Spitfire, NYXL & Dynasty. Valiant is trying to cling to the group after losing to two of them. Then there is the rest of the field, with Shanghai holding down the bottom. We can expect to see a view at their relative power in the next couple weeks, with Dynasty vs. Excelsior in Week 3 & Dynasty vs. Spitfire in Week 4.

Three questions for week 2

The value of a ranking like this is in how you can juxtapose it against existing storylines & ‘gut feel’ on the competition. I think two questions bubble to the surface. First, will Houston rise? There was a lot of hype for this team heading into the season based on their history as a mostly existing team. Two tough week 1 losses led into two resounding wins in week 2. This week they have a chance to prove themselves against Seoul after a softer matchup with Florida.

Second, is Valiant top-tier or mid-tier? Right now, they are trying to cling to the top group after losses to NYXL & London. They have a chance to prove themselves with a couple face-offs with other mid-tier opponents, leading off with their crosstown rivals.

Finally, how will the top shake out? We have a few tests for the 3 undefeated teams this week. Seoul Dynasty & New York Excelsior face off on Friday which will knock out one undefeated team. The margin will tell us a story of the relative strengths of these teams. Before that, Seoul will be facing off with a Houston Outlaws team that trying to maintain momentum after a poor start in week 1.

Meaningful?

One closing comment. Elo relies on match history & match diversity to get into its grove. I’ve tried to jump-start this by allowing the rating to move more significantly in the first couple weeks. At 4 matches, teams have only played 25% of available teams. As a reference, in chess an Elo rating is considered preliminary until 26 matches. Over 4 opponents each team is at approximately 16 matches.

That being said, we can expect the model to continue to learn from these results aver the coming weeks. We will be along for the ride & see how this model can inform our viewing.