What is MMR?
MMR or MatchMaking Rating is a number used by League of Legends to represent a player's skill level. During matchmaking, teams are formed by grouping together players with similar MMR. Each game mode has its own separate MMR, but WhatIsMyMMR specifically tracks ranked, normal, and ARAM queues. Read more about MMR on Riot's website.
How accurate is WhatIsMyMMR?
The site provides MMR estimates with a 95% confidence interval shown as ± some number. For example, an estimated MMR of 1200 ±100 means that the actual MMR is likely somewhere between 1100 and 1300. Because the estimate represents a range of possible values, winning a game might not immediately increase your MMR (in some cases, the nominal estimate might actually decrease to account for the additional data). Playing more games ultimately increases the accuracy of the estimate and provides data to show historical MMR trends.
Why is there no estimate available?
Estimates require a certain amount of data from solo (non-premade) games; try playing more games by yourself. WhatIsMyMMR excludes premade games because players in the party can have very different MMRs which causes poor matchmaking and inaccurate MMR estimates.
How do I improve my MMR?
MMR goes up when you win and down when you lose (see the section above on accuracy for caveats). As such, the most straightforward way to gain MMR is to maintain a positive win rate. Although the difference between your team and the opposing team's average MMR affects the amount gained or lost, in practice most games are "fair" and matchmaking tries to pair teams with similar MMR. A good rule of thumb is +10 MMR for a win and -10 MMR for a loss.
How does MMR affect ranked LP?
The amount of League Points (LP) gained or lost depends on the difference between your team's MMR and the average MMR of your tier+division. For example, a Platinum I player who wins a game at 2300 MMR (approximately Diamond I) will see much larger LP gains than winning a game at 1800 MMR (approximately Platinum I). Note that MMR and LP are different from Elo rating, the old ranking system that removed by Riot in Season 3.
Does queue dodging affect my MMR?
No, dodging in champion select does not affect MMR. However, ranked queues have various LP and promotion series penalties for dodging.
Does WhatIsMyMMR have an API?
Yes! WhatIsMyMMR provides a comprehensive public API for developers who want to use MMR results in their own project. Documentation can be found on the developer portal.
Who built this and how can I support it?
Hi, I'm Josh. I built WhatIsMyMMR as a weekend project for personal use and eventually released it publicly in 2016. The site is surprisingly expensive to run each month and is only possible through the support of the amazing patrons on Patreon.