Chess ELO Rating

In chess the ELO rating system is a method for calculating the relative skill levels of a player. It is named after its creator Arpad Elo, a Hungarian-American physics professor.

Two players that have an equal ELO rating are expected to score an equal number of wins against each other. After every game, the winner takes ELO points from the player who lost the game. If the high rated player wins then only a few points will be taken from the low rated player. However, if the lower rated player scores an upset win then many rating points will be taken. The lower rated player will also gain a few points from the higher rated player in the event of a draw.

The player will be asked for a chess skill level when first connecting to the server. The beginner, intermediate and advanced skill options will give 800, 1200 and 1600 ELO points respectively. The player should answer that question honestly. Players whose ratings are too low or too high than their skill level, in the long run, do better or worse correspondingly than the rating system predicts.

The ELO K value referring to the constant or power used in ELO math is set to the value of 30.