Elo is a rating system for two-player games, originally invented in the 1960s by Arpad Elo, a Hungarian-American physics professor and chess player. In League of Legends, "elo" is now community shorthand for your matchmaking rating: the hidden skill number that decides who you get matched against and how much LP you gain or lose. The visible numerical Elo system was actually used in LoL through Seasons 1 and 2 and removed at the start of Season 3 in 2013, but the word stuck.
One thing every guide gets wrong: it's Elo, not ELO. It's not an acronym. It's a guy's last name.
Elo Is a Surname, Not an Acronym
Arpad Elo published the rating system in the 1960s for the United States Chess Federation. Because gaming forums shouted everything in caps for years, "ELO" became the de facto spelling, and a lot of players still assume it stands for something like "Electronic League Organization." It doesn't stand for anything. The correct spelling is "Elo," capital E only, the same way you'd write any other surname. The chess community is strict about it. The LoL community, mostly, is not.
How the Elo Math Works
The core idea is simple. Every player has a rating. Before a match, the system uses the difference between the two ratings to predict an expected outcome. After the match, the difference between the actual result and the expected result is used to adjust both ratings.
The standard chess formula:
- Expected score for player A:
Ea = 1 / (1 + 10^((Rb - Ra) / 400)) - New rating for player A:
Ra_new = Ra_old + K * (Sa - Ea)
Sa is the actual result (1 for a win, 0 for a loss, 0.5 for a draw in chess). K is a scaling factor that controls how big each swing is: new or unstable players get a higher K so the system locks in on their true skill faster, and established players get a smaller K so a single bad day doesn't trash their rating.
One useful intuition: a 400-point gap means the higher-rated player is 10 times as likely to win. Beat someone 400 points above you and you gain a lot; beat someone 400 below you and you barely gain anything. Lose to someone way below you and you lose a lot. The system always pulls you toward the rating that matches your actual win rate against opponents of various strengths.
LoL's Original Elo System (Seasons 1-2)
From launch in 2009 through the end of Season 2, League of Legends used a visible numerical Elo rating. Every player started ranked play at 1200 Elo and the rating was hidden for the first 10 placement games. After placements, your number was public on your profile and on the ladder.
The Season 1 medal cutoffs in Solo 5v5 were:
- Bronze: 1250 to 1399 Elo (top 25% of ranked players)
- Silver: 1400 to 1519 Elo (top 10%)
- Gold: 1520 to 1899 Elo (top 3%)
- Platinum: 1900+ Elo (top 0.2%)
K-factor in LoL was around 100 for new players and about 25 for established accounts, so early ranked games swung your rating harder. In September 2012, two months before the end of Season 2, Riot added Diamond as an apex tier above Platinum and split each tier into Roman-numeral subdivisions in 50-Elo increments. Decay also applied above 1400 Elo: Diamond lost 50 Elo per 28 days of inactivity, Platinum 35, Gold 25, Silver 10.
The visible system was retired at the start of Season 3 in January 2013. Riot's stated reason in the Season 3 FAQ was that a single global ladder with hundreds of thousands of players offered no meaningful sense of progress: when you're ranked 290,000, climbing feels meaningless. The League/LP/tier system replaced it. China's servers actually kept the old Elo system running well into Season 3 because of implementation issues.
Modern MMR Is Elo-Shaped, but Not Confirmed Elo
The current matchmaking system in LoL uses a hidden Matchmaking Rating, abbreviated MMR (or hMMR). The wiki and Riot's own documentation describe it as a per-queue skill rating that's "indefinitely hidden" and whose "exact parameters are proprietary to Riot Games."
What we know for certain:
- MMR is per-queue. Your Solo/Duo MMR, Flex MMR, and normal-game MMR are tracked separately. Riot's 2018 dev blog stated this explicitly.
- MMR is based on win/loss against opponents of known skill, not KDA or scoreline. The wiki is direct about this: "statistics such as scorelines (KDA, Creep score, etc) are not considered in any way."
- MMR converges toward a target win rate of roughly 50%. Riot's 2018 blog said most teams have an expected win rate of 50% +/- 1%.
- MMR is intentionally separate from your visible rank because, as Riot put it, "using MMR as the sole mark of achievement punishes half of the playerbase."
What we don't know is whether the underlying math is literally Elo. The behavior matches Elo: win/loss-driven, opponent-strength-weighted, drifts toward true skill. But Riot has never published a formula. It could be classic Elo with custom K-factors, Glicko (which adds a rating deviation term), TrueSkill (Microsoft's multiplayer Bayesian system), or a fully custom algorithm with team-weighted adjustments. The wiki notes that Riot uses "various weights to adjust for a more deterministic approach" on top of an Elo-like base. So: Elo-shaped, not confirmed Elo.
For more on how to read your own MMR off LP gains, see our guide to checking your MMR, and for how MMR maps to the visible tier ladder, the full LoL ranks breakdown covers it.
Why Players Still Say "Elo"
Riot replaced the visible Elo number with LP and tiers in 2013, but they didn't replace the word. The 2013 FAQ deliberately said "our matchmaking system still matches you by skill level, but this 'rating' is no longer visible." The number went away; the concept stayed. Players had been saying "high elo" and "low elo" for two seasons, so the slang outlived the system that named it.
Today "elo" in League of Legends conversation usually means one of:
- Your hidden MMR ("my elo is way higher than my rank")
- Your skill bracket ("low elo," "mid elo," "high elo")
- The matchmaking system in general ("the elo system is broken")
The community consensus on bracket boundaries, captured fairly accurately in a popular 2024 r/leagueoflegends thread, is that Iron through Silver counts as low elo, Gold through Emerald is mid elo, and Diamond and above is high elo. Riot's internal definitions are stricter: their "Elite" skill bracket starts at Diamond I, and patch-note language that flags "high elo" effects usually means the top fraction of a percent of the player base. There's no official cutoff, the brackets shift slightly with every rank distribution change, and the definitions are fuzzy on purpose.
"Elo Hell" Is Mostly Not Real
"Elo hell" is the idea that the matchmaking system traps you with bad teammates at a rank below your true skill. Riot's official position, going back to a 2014 matchmaking FAQ and reaffirmed in the 2018 dev blog, is that this is largely a misperception.
The data Riot has shared:
- The 2014 FAQ estimated 150 to 300 games to reach your true MMR; statistical noise from teammate variance flattens out across that volume.
- Most players self-rate their MMR around 150 points above where the system actually rates them, consistent with Dunning-Kruger.
- The 2018 blog directly addressed "loser queue": "There's nothing in the MMR system that forces you to have lower-skill teammates or disproportionately higher-skill opponents." Riot also acknowledged the pain is real, but framed it as a perception problem.
A single bad streak feels like elo hell because your last 10 games are vivid and the overall trend is invisible. Across thousands of games, players who deserve to climb climb. The fix is volume.
What "Climbing Elo" and Other Phrases Mean
- "I'm climbing elo": gaining MMR, usually visible as larger LP gains than losses.
- "My elo is higher than my rank": hidden MMR is ahead of visible LP/tier, often after placements or a win streak.
- "Got boosted": duo'd with someone better and got carried above their actual MMR. Riot now penalizes rank manipulation with escalating bans.
- "Stuck in elo hell": a feeling, not a system state.
- "Elo check": looking up an estimated MMR through op.gg or mobalytics. Estimates from match history, not Riot's actual stored value.
When KDA and Win Rate Matter More Than Elo
One reason "elo" gets overused is that players treat it as a proxy for individual performance. It's not. Elo (or MMR) measures match outcomes against opponents of known strength. It says nothing about whether you played well in any single game.
For decision-making at the individual level, two stats matter more:
- Win rate on a champion over 30+ games. If you're 40% on Yasuo and 58% on Sett, your elo is mostly telling you to play more Sett.
- KD ratio relative to your role's baseline. A 3.0 KD as an ADC in Gold is genuinely good. A 3.0 KD as a Sona support tells you your team was stomping and the stat doesn't mean much. KD without context is noise.
Elo tells you which bracket you're in. Win rate and KD by champion tell you which decisions to make to leave it. The most common mistake in low elo is staring at the rank icon instead of the champion-by-champion match history that would actually move it.
Frequently Asked Questions
Is "Elo" an acronym?
No. It's the surname of Arpad Elo, the Hungarian-American physics professor who created the rating system for chess in the 1960s. The all-caps spelling "ELO" is a community convention, not a correct one.
Does LoL still use the Elo system?
The visible numerical Elo system was removed at the start of Season 3 in January 2013 and replaced with the League/LP/tier system. The hidden Matchmaking Rating that runs underneath behaves like Elo (win/loss-driven, opponent-weighted, drifts toward true skill), but Riot has never confirmed the exact algorithm and treats the formula as proprietary.
What rank counts as high elo?
There's no official threshold. Community consensus in 2024-2026 puts low elo at Iron through Silver, mid elo at Gold through Emerald, and high elo at Diamond and above. Riot's internal "Elite" skill bracket starts at Diamond I.
Can I see my Elo in-game?
No. Riot does not display your MMR. Third-party tools like op.gg and mobalytics estimate it from your match history, but those are educated guesses, not Riot's actual stored value. The most reliable read on your MMR is your LP gain per win versus your LP loss per loss: significantly more than 25 LP per win means your MMR is ahead of your visible rank.
What does "elo" mean in Valorant, CS, or Overwatch?
Same idea as in LoL: a hidden skill rating that drives matchmaking. Most modern competitive games use "MMR" as the official term and reserve "Elo" for chess, but players carry the word across titles anyway. Valorant's docs say "MMR." So do Riot's own League docs, technically. The community says "elo" anyway.
