Rating System
30.06.2019 15:05

Tournament rating is calculated using ELO system using the following formula (for two players А and В):

Rа, new = Rа, previous + К * (Са - Еа)

Rа, new – new rating of player A in the tournament;
Ра, previous – current rating of player A in the tournament;
К – index 30 if rating value is less than 2000, index 20 – when rating is from 2000 to 2400, index 10 if rating value is higher than 2400;
Са – number of points scored de facto by Player A (1 point for win, 0,5 for a draw game and 0 for loss );
Еа – expected score for Player A, calculated on the basis of Player's rating.

Еа = 1 / (1 + 10 ^ ( (RB, previous – Ра, previous) / 400 ))

Match result will influence the Players' global rating in the same way with the only difference – the Players' global rating will be used for calculation, not the tournament ratings.

x = - b ± b 2 - 4 a c 2 a