The Glicko rating system is a method used to calculate the skill levels of players in competitive games. Developed by Mark Glickman, it improves upon the traditional Elo rating system by incorporating a measure of uncertainty in a player's rating. This uncertainty reflects how much a player's skill level is known, allowing for more accurate adjustments after each match. In the Glicko system, each player has a rating, a rating deviation (RD), and a volatility measure. The rating indicates skill level, the RD shows the confidence in that rating, and volatility represents how much a player's performance can vary. This system helps ensure fair matchmaking in games and tournaments.