Rating Calculation

Rating Algorithm – ECF Online Ratings are four digit elo numbers calculated based on online results received for ECF members club and other registered events using the monthly grading formula published on the ECF web site here – Monthly Grading. The elo formula is applied to calculate the rating change from each result as follows: Rnew = Roriginal +k (W-We) where Roriginal is the starting rating, k is the k factor for the player and W-We is the actual result minus the expected result based on the elo probability table.

Starting Ratings – An initial 4 digit elo ‘seed rating’ has been provided for players taking part in online rated events based on converted ECF OTB standard grades (for online standard rating) or converted ECF OTB rapid grades (for online rapid or blitz ratings). OTB standard ratings have been used where no rapid rating is available and vice versa. Where no OTB ratings are available FIDE elo ratings have been used where known, or otherwise the player’s internet provider rating at the start of the period. The ECF standard conversion formula has been used where relevant to calculate ‘seed ratings’ from ECF grade as follows: FIDE ELO rating = 7.5*ECF+700.

Time Controls – Internet ratings are provided separately for standard games, rapid games, and blitz games, and are calculated using the standard elo formula applied to online games between ECF club members.
Guidelines for applicable time controls are as follows:

Standard Games – Games played with 60 minutes or more per player for the game.
Rapid Games – Games played with more than 10 minutes and less than 60 minutes per player for all moves in the game.
Blitz Games – Games played with between 3 and 10 minutes for all moves in the game.

Where increments are used the ‘duration’ of the game for rating purposes is calculated on the basis of a 60 move game.

ECF Internet ratings are based on internet club/ team games and registered online events only and are completely separate from ECF OTB ratings which will not be impacted by internet games.)