Reference
Learn chess
Foundations and references — rating systems, comparisons, and the concepts behind how ChessRef measures play.
Foundations
Learn Chess
How the game works, how ratings work, and what to focus on at each level.
Read →Rating
Elo Rating System
How ratings are calculated, what K-factor means, and how rating systems compare across sites.
Read →Tool
Convert Ratings
Translate ratings between Chess.com, Lichess, FIDE, and USCF across time controls.
Read →Comparison
Lichess vs Chess.com
Differences in ratings, features, time controls, and which site fits which kind of player.
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