ELO rating system in Chess

-The Elo rating system is a method used to calculate the relative skill level of players in chess and other competitive games. It was developed by Arpad Elo, a Hungarian-American physicist and mathematician, in the 1960s and has been widely adopted in the world of chess and other mind sports.

-The Elo system is based on the idea that the probability of one player winning a match against another is determined by the difference in their ELO skills. The greater the difference in Elo rating between two players, the lower the probability that the player with the lower ELO rating will win the match.

-A player's Elo rating increases or decreases after each game, depending on the outcome of the match and the difference in skill between the players. If a player with a higher Elo rating wins against a player with a lower Elo rating, the winner's rating will increase only slightly, while the loser's rating will decrease by a proportionally larger amount. Conversely, if the player with the lower Elo rating wins against a higher rated opponent, his rating will increase significantly, while the opponent's rating will decrease.