Harkness Rating System
For simplicity, OCC uses the Harkness Rating System. All games; Ladder, Round-Robin, Swiss, Knockout, or Tournament will use this system.
HARKNESS SYSTEM*
Opponent Rating Difference | If High Wins Add to Winner and Deduct from Loser | If Low Wins Add to Winner and Deduct from Loser | If a Draw Add to Low Deduct High |
---|---|---|---|
0 to 24 | 16 | 16 | 0 |
25 to 49 | 15 | 17 | 1 |
50 to 74 | 14 | 18 | 2 |
75 to 99 | 13 | 19 | 3 |
100 to 124 | 12 | 20 | 4 |
125 to 149 | 11 | 21 | 5 |
150 to 174 | 10 | 22 | 6 |
175 to 199 | 9 | 23 | 7 |
200 to 224 | 8 | 24 | 8 |
225 to 249 | 7 | 25 | 9 |
250 to 274 | 6 | 26 | 10 |
275 to 299 | 5 | 27 | 11 |
300 or more | 4 | 28 | 12 |
*Official Chess Handbook, p. 156