Definitions for "Elo rating"
an internationally accepted statistical system for ranking chess players, created by Arpad Elo in 1960 and adopted by FIDE in 1970; it is a numerical representation of a player's success rate and approximation of strength. International Grandmasters are typically in the range 2500 to 2700, world champions often over 2700; many games must be played before an Elo rating can be estimated with confidence. Obviously, two players with the same rating should have an equal chance of winning against each other. Less obviously, the same rating difference implies the same chance of winning: a player rated 2400 playing against a player rated 2200 has the same chance of winning as a 1400 against a 1200. The Elo rating is the foundation for the award of FIDE titles. FIDE publishing & printing
An internationally accepted mathematical system for ranking chess players, created by Arpad Elo. International Grandmasters are typically in the range 2500 to 2700, world champions often over 2700. The standard deviation is 200 points. The scale is such that a player at 1800 would be expected to beat one at 1600 by the same margin as a player at 2600 against one at 2400. Many games must be played before an Elo rating can be estimated with confidence. The Elo rating is the foundation for the award of FIDE titles.
This form of rating system uses a formula to determine how many points you gain or lose from a given match. If you beat someone who has a higher rating than you, you will win more points than someone who has a lower rating than you. Likewise, if you lose to someone with a higher rating, you will lose fewer points than if you lose to someone lower than you.