STRENGTH OF SCHEDULE (SOS) EXPLANATION


Strength of Schedule (SOS) is a rating which measures the difficulty of a team's schedule such that the stronger the opponents, the higher the SOS rating, or conversely, the weaker the opponents, the lower the SOS rating. In order to tabulate an SOS rating, the opponent's strength has to be evaluated. All calculations are based only on a teams W-L record and that is an indication of the opponents strengh. There are two components of tbe SOS (1) the average of the the opponent's W-L percentage and (2) the average of the opponents opponent's W-L percentage. The first component is weighted 2/3 and the second component is weighted 1/3 and the sum is the SOS. For example, A team has played 8 of its 12 games through the season. The team's record is 7 wins and 1 loss or 0.875. The records for the opponents are as follows: Team A 5 3 .625 Team B 4 3 .571 Team C 2 5 .286 Team D 3 4 .428 Team E 7 1 .875 Team F 2 5 .286 Team G 2 5 .286 Team H 9 0 1.000 -- -- 34 26 .545 Note that the .545 is not based on 34/60 (.567) but on the average of each opponent's percentage in the right-hand column.
The records for each opponent's opponents are: Team A 42 18 .750 Team B 22 24 .502 Team C 18 18 .483 Team D 32 22 .600 Team E 30 31 .530 Team F 29 15 .624 Team G 37 16 .645 Team H 39 27 .615 --- -- 249 171 .594 Note that the .594 opponent-opponent figure above is not based on 249/(249+171) but rather is the average of the percentages in the last column. The RPI for our example team is then computed as follows: Opp Rec (2/3) Opp-Opp Rec (1/3) W/L PCT. W/L PCT. 0.667 0.333 SOS = (0.667 * 0.545) + (0.333 * 0.594 = 0.562 Advantages: Uniformity throughout all NCAA Sports since it is based strictly on wins and losses. It is a straight forward and simple calculation. Disadvantages: Does not take into account goal margin of victory so that a victory by one goal carries the same weight as a victory by 15 goals. Further if there is not much crossover between two regions, than the results are meaningless when coparing teams from different regions.