Methodology

In short

Every team has a Home Elo rating, updated after every game it plays. Every region has a region adjustment, updated only when its teams play teams from other regions at internationals. Adding the two gives Effective Elo, which puts every team in the world on one scale. Win probabilities come from the gap between two teams' ratings. Historical questions use the ratings as they were at the time, not today's.

Terms

Home Elo

A team's rating from its results, measured within its own league. Also called domestic Elo. A Home Elo only compares teams fairly within one region: 1600 in the LCK and 1600 in a smaller league are not the same strength.

Region adjustment

How far a region's teams run above or below the average region, in Elo points. Also called the region offset. The average region is 0; a region at +300 is 300 points stronger than average. Set only by inter-region games at international events.

Effective Elo

Effective Elo = Home Elo + region adjustment. The rating used to compare or rank teams from different regions, and the plain "Elo" on the global rankings. For two teams from the same region the adjustments cancel, so Home Elo alone gives the same odds.

Elo going in

A team's rating immediately before the first game of a match (pre-match Elo). Used for pre-match odds and upsets, so a result is judged against what was known at the time.

Game win probability

The chance of winning one game: 1 / (1 + 10^((opponent − team) / 400)). A 100-point edge is 64%; a 400-point edge is 91%.

Series win probability

The chance of winning a whole best-of-N, from the game probability, assuming each game is independent: the sum, over every way of reaching the needed wins first, of that path's probability. A 100-point edge is 70% in a best-of-3 and 75% in a best-of-5: longer series favor the stronger team.

Winner's odds

The series win probability the eventual winner had going in: the lower it is, the bigger the upset. A winner at 8% is a far larger upset than one at 42%.

Elo change

How much Home Elo a team gained or lost. Ratings update after every game, not once per series, so a match's Elo change is the sum of its games. Points are zero-sum: what the winner gains, the loser loses.

How Home Elo updates

• After each game the winner takes K × (1 − win probability) points from the loser, with K = 32. Beating an even opponent is worth 16 points; beating a much weaker one, only a few.
• At internationals the win probability uses both teams' Effective Elo, so beating a team from a stronger region is worth more. The points still move between the two teams' Home Elo.
• A team new to the system starts at 1450. In the first season of a newly tracked league, every team starts at 1500.
• Between seasons, each team's rating moves 40% of the way back toward 1500, since rosters change in the off-season. A team that was absent for more than a year restarts at 1450.
• Games come from Leaguepedia and ratings are recomputed throughout the day. Results only count once they're on Leaguepedia.

How region adjustments update

• Only games between teams from different regions at international events (Worlds, MSI, First Stand and others) move region adjustments. Domestic games never do.
• Each such game moves the winner's region up and the loser's region down by the same amount, K = 22 × (1 − win probability), so the average region stays at 0.
• Between years, each region's adjustment shrinks 5% toward 0.
• A region's first appearance starts at 0 for the long-established major regions and at -100 for others, until its results move it.
• A team counts for the region of the league it most recently played in domestically, at the time of the event.
• A region with no international results can't be placed on the shared scale, so its teams are left off the global rankings rather than guessed at. Early years have few international games, so cross-region comparisons from then are rough; the pages say so when that applies.

Current and past adjustments are on the region power rankings.

Coverage and limits

• History starts in 2014 for the LCK (then Champions), LPL, the European and North American LCS, CBLOL, and Worlds, and in 2015 for MSI. Smaller leagues start later.
• The model knows only who beat whom. It doesn't see rosters, patches, sides, or drafts, so a mid-season roster change shows up only as the results change.
• Series odds assume games are independent. Real series aren't quite, so treat odds as a baseline.

Linking to any view

Every view below has a stable URL, so you, a script, or an AI assistant can open it directly. Teams go by name or abbreviation (t1, gen-g, team-liquid); dates are YYYY-MM-DD.

/rankings?date=2026-10-22

Global rankings (Effective Elo) and region adjustments as of the end of a given day.

/rankings?year=2024

Global rankings at the end of a season.

/series/lck-2025

One league's season: rating chart and standings. Format: /series/{league}-{year}.

/series/lck-2025/matches

Every match that season with Elo going in, odds, result, and Elo change.

/elo-calculator?a=t1&b=gen-g&date=2026-10-22&bo=5

Head-to-head odds for any two teams as of any date, for a best-of-1, 3, or 5.

/elo-calculator/rating?team=t1&date=2026-10-22

One team's Home Elo, region adjustment, and Effective Elo on a date, as JSON.

/sitemap.xml

Every season and match page.