The ELO rating is a mathematical system that assigns each chess player a number reflecting their playing strength, making it possible to compare players and find balanced opponents.
Designed by physicist and chess player Arpad ELO in the 1960s, the system works on a straightforward principle: every game adjusts both players' ratings based on the result and the expected outcome given the rating difference. If a lower-rated player beats a stronger opponent, they gain more points than they would from beating someone of equal strength. Conversely, losing to a much weaker player costs more points. For instance, a 1200-rated player who consistently beats 1300-rated opponents will gradually see their rating climb toward 1300.
In practice, an ELO rating serves as a compass for measuring progress. Beginners typically start between 800 and 1000, an intermediate level sits around 1200–1400, and a solid club-level player generally exceeds 1600. Rather than focusing on every point gained or lost after a single game, it is more meaningful to observe the trend over several weeks or months — that curve is what truly reflects improvement.