The lower rated player will also gain a few points from the higher rated player in the event of a draw.
This means that this rating system is self-correcting.
The difference between the ratings of the winner and loser determines the total number of points gained or lost after a game.
After every game, the winning player takes points from the losing one.The Elo system was originally invented as an improved chess rating system, but is also used as a rating system for multiplayer competition in a number of video games, Major League Baseball, Scrabble, snooker and other games.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 are expected to score an equal number of wins.
A player whose rating is 100 points greater than their opponent's is expected to score 64%; if the difference is 200 points, then the expected score for the stronger player is 76%.A player whose rating is too low should, in the long run, do better than the rating system predicts, and thus gain rating points until the rating reflects their true playing strength.