FargoRate rates pool players worldwide on the same scale based on games won and lost against opponents of known rating. We compute the optimum set of ratings--also known as the maximum likelihood ratings--that best predict the outcome of all the games amongst all the players. Ratings based on more data are more reliable. Established ratings are those based on 200 or more games.

There is no top or bottom to the rating scale. About two thirds of established ratings are between 370 and 590, and about 95% of established ratings are between 260 and 690. Professional players generally have ratings above 700 with elite world-class players above 800. Most competitors in leagues and tournaments have ratings between 200 and 700.

The rating difference between two players reflects the chance each will win a game. Two players with the same rating, i.e., a 300 versus another 300 or a 600 versus another 600, have equal chance of winning a game. Multiple games between them will tend to be won in a 1:1 ratio. When two players are 100 points apart, say a 300 versus a 400, the ratio of game wins will be near 1:2, as in 5 games to 10 games. A 200 point difference leads to a 1:4 game win ratio, and a 300 point difference leads to a 1:8 game win ratio.