What is Elo System?

The Elo System refers to a method for calculating the relative skill levels of players in zero-sum games such as chess. Named after its creator, Arpad Elo, it is a statistical system based on the assumption that a player's performance in any game is a random variable. The system generates numerical ratings for each player which can predict with a probability the outcome of a future game. The difference in ratings between two players determines the expected result of a match between them. the Elo System is used by organizations such as FIDE (World Chess Federation) to rank players and establish their standing in global and local competition rankings.