Learn about How to Track League of Legends Matchmaking Rating

Here is a guide about how to check your League of Legends MMR through https://lolmmr.com/ which calculates MMR based on multiple skill level factors. You can also say that it is your skill level score.

Here is an overview of the League of Legends MMR:
Matchmaking Rating (MMR) in League of Legends is a hidden numerical value assigned to each player to determine their skill level. It is used by the game's matchmaking system to create balanced teams in online matches. The primary goal of MMR is to ensure that players compete against others of similar skill, providing a fair and competitive environment.

MMR is calculated based on various factors, including the outcomes of matches and the relative skill levels of the opponents. Winning against higher-ranked opponents can significantly boost a player’s MMR, while losing to lower-ranked opponents can cause a more substantial drop. This system ensures that players who consistently perform well will climb the ranks, while those who do not will face lower-ranked opponents.

The MMR system operates in the background and is distinct from the visible rank system (such as Bronze, Silver, Gold, etc.). While a player's rank provides a rough estimate of their skill level, MMR is a more precise measure. Changes in MMR can occur even if a player's visible rank remains the same, as MMR adjustments happen continuously after each game.

A concept known as "Elo hell" is often discussed by players, referring to the belief that they are stuck in a lower rank due to factors outside their control, such as poor teammates or bad luck. However, MMR is designed to mitigate such issues over time, as consistent performance should eventually lead to an accurate representation of a player’s skill.

MMR decay is another aspect to consider. When players are inactive for an extended period, their MMR can decrease, leading to a lower rank upon their return. This is implemented to ensure that active players remain competitive within the current meta.

Understanding MMR is crucial for players aiming to improve their rank, as it emphasizes the importance of consistent performance and adaptation. By focusing on improving individual skills and understanding game mechanics, players can positively influence their MMR and achieve higher rankings.