The following chart is the graphical representation of the original (1947) Hotchkiss-Wilcock linear equations. This statistical sytem, the forerunner of all numeric rating systems in use today, is still utilized by CCLA. Class names and 200-point intervals used by FIDE were adopted in 1980. Points gained by one player are lost by the other, except for challenge matches of more than two games.
Rating difference is the difference in ratings at the time the game is concluded Column 1.
If the higher-rated player wins, he gains the number of points listed in Column 2 and his opponent loses the same.
If the lower-rated player wins, he gains the number of points listed in Column 3 and his opponent loses the same.
If the result is a draw, then the lower-rated player gains the number of points listed in Column 4 and the higher-rated player loses the same.