The Elo rating system is a method for calculating the relative skill levels of players in competitor-versus-competitor games such as chess. It is named after its creator Arpad Elo, a Hungarian-born American physics professor.
The Elo system was invented as an improved chess rating system and is also used in many other games. It has also been adapted for use as a rating system for multiplayer competition in a number of video games, and has been adapted to team sports including soccer (association football), American college football, basketball, Major League Baseball, competitive programming, and E-Sports.
The difference in the ratings between two players serves as a predictor of the outcome of a match. Two players with equal ratings who play against each other multiple times are expected to score an equal number of wins. A player whose rating is 100 points greater than their opponent’s is expected to win 64% of the time; if the difference is 200 points, then the expected win proportion for the stronger player is 76%. … Elo Rating System