Chess: Calculating Rating Points
Zone.com uses the rating formulas established by the U.S. Chess Federation (USCF). The USCF's rating system divides players up into three rating-point categories. The higher the point category, the lower the cap on points that players can earn from a given game. For more information about the USCF rating system, please see U.S. Chess Federation's Web site.
Here are the USCF formulas on how to calculate your Chess rating points. Please note that Zone.com does not use provisional ratings for Chess . You begin with 1600 rating points. Your rating points will increase when you win a game and decrease when you lose a game.
Rn = Ro + K(W-We)
Rn is the new rating.
Ro is the old (pre-event) rating.
K is a constant value based on your rating category. For 0-2099 rating, K = 32.
For 2100-2399 rating, K = 24.
For 2400 rating and above, K = 16.
W is the score in the event. For a win, W = 1.
For a loss, W = 0.
For a tie, W = 0.5.
We is the expected score (Win Expectancy), which can be calculated from the following formula: We = 1/(10(dr/400) + 1)
"dr" equals the difference in ratings.
"K" is a major factor in calculating your rating points. To receive the maximum number of rating points for a single match, challenge and beat a player who has 800 more rating points than you.
If you win a game and your current rating is:
(0-2099), you will receive between 1 and 32 points.
(2100-2399), you will receive between 1 and 24 points.
(2400 and above), you will receive between 1 and 16 points.
If you lose a game, you will lose the above number of points.
If a player falls into a different rating category after playing in a game, the number of points the player won or lost is decreased. This is to minimize the role of luck in the progression up or down and to ensure that players of comparable skill level are steadily being matched against each other. One of the following equations is used to adjust the post-game rating:
Pre-game Rating Post-game Rating
0-2099 2100-2399 Ra = 2100 + (Rn - 2100) x 0.75
2100-2399 0-2099 Ra = 2100 + (Rn - 2100) x 1.33
2100-2399 2400-3000 Ra = 2400 + (Rn - 2400) x 0.66
2400-3000 2100-2399 Ra = 2400 + (Rn - 2400) x 1.50
Where Rn is the post-game rating and Ra is the "crossing K factor" adjustment. Ra becomes the new post-game rating.
Note that the program will never drop a player's rating below 100 points.
Se bem q acho q sera perciso um ajuste pro UT, pq no xadrez vc joga contra 1, no UT tem varios.
Acho q o esquema deveria ser assim, quando termina a partida vc é comparado com todos q jogaram, por exemplo um cara q terminou em 4° e tem 10 no server, ele ganharia 10-4= 6xN - 4xN, quem ficou em primeiro ganahria 9xN(esse N seria um numero escolhido no caso de cada vitoria)
O foda desse sistema é q nao tem a perda de pontos maior caso vc perca pra um cara com pontuaçao baixa, o ngworldstat tinha isso. So q ta fora do ar e nao da pra ver como eles calculavam.
Pergunta: como vcs estao contando os pontos?
Olha, esse esquema de rating é melhor, so q é bem mais foda