Chess rating

Rating is a numeric equivalent of the relative strength of a chess-player. Statistically it indicates the probability of the given result of the game between two players. The greater difference in the ratings of two players is the more predictable the result of such game will be.

Rating system is the algorithm of calculating player’s rating. Currently the rating system of professor Elo is used as an official FIDE Rating System. Regardless of its popularity it has certain disadvantage, that is why the site uses a different one: professor’s Glicko rating system.

Its key difference from Elo rating is that it has statistical accuracy factor introduced which is dependable from the time of the player’s inactivity. The more time the player was not taking part in games the greater this inaccuracy factor is. This factor is individual for each of the players. That is why the rating increment value after the particular game can differ for each player. This increment will be greater for the player who wasn’t playing for a longer period of time. For example, one player can get 100 points for winning the game, but his opponent will loose only 10. More detail information here.

The player has individual ratings on the site for each game timing type and game type, i.e. the games with different timing type and game type are calculated separately.