Ratings are based on a specific formula that factors in your current rating, the rating of your competition, the number of rated games you've played and your win expectancy, which is calculated using the difference between your rating and your competitor's (or the average of your competitors' ratings if you are playing against two or more people). If you have not yet played any rated games, your current rating is set to 1200.
Ratings are determined based on a modification of the widely used system developed by Prof. Arpad Elo, former president of the American Chess Federation. Upon completion of a rated game, each player's new rating is calculated according to the following formula:
Rn=Ro+K(W-We)
where:
• Rn = new rating.
• Ro = rating before playing a game (new players start with a rating of 1200).
• K = 128 if player has played fewer than 10 rated games; or
o 64 if player has played 10 or more but fewer than 20 rated games; or
o 32 if player's rating is below 2100 after 20 or more rated games; or
o 24 if player's rating is 2100 or more but below 2400 after 20 or more rated games.
o If none of the above conditions is true, K = 16
• W = score for the game you just completed. A win is worth 1 point, a tie is worth 0.5 points and a loss is worth 0 points.
• We = expected score (win expectancy), as determined by the following formula:
We=one over 10(dr over 400)+1
where dr is the difference between the player's rating and his or her competitor's (or the average of the competitors' ratings if there are two or more in the game).
If there is a mistake anywhere i will edit it. If you think this rating formula is wrong let me know.
Originally posted by tlai1992so if you are a 1200 played less than 10 games and you beat a 1300
Ratings are based on a specific formula that factors in your current rating, the rating of your competition, the number of rated games you've played and your win expectancy, which is calculated using the difference between your rating and your competitor's (or the average of your competitors' ratings if you are playing against two or more people). If you ...[text shortened]... e is a mistake anywhere i will edit it. If you think this rating formula is wrong let me know.
1291=1200+128(1-.285714)