Strength Of Schedule (SOS)

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Strength Of Schedule (SOS) represents a team’s average schedule difficulty faced by each team in the games that it’s played so far or for all season. The schedule difficulty of a given game takes into account the rating of the opponent and the location of the game.

Strength of schedule in the NBA has not been considered nearly as important as in the NFL or as in the NCAA basketball since the NBA teams play each other at least twice. Much of the schedule differences between teams come down to road trips, back-to-backs, afternoon games for example.

Strength of schedule can be calculated in many ways and all methods asssign a greater SOS number to a more difficult schedule.

Methods for Calculating Strength Of Schedule

SOS can be calculated by the help of Relative Percentage Index which incorporates W/L records of opponents and opponents’ opponents. This method is being used by ESPN. John Hollinger explains the calculation of SOS.

Simple Rating System (SRS) also incorporates strength of the schedule by employing margin of victory (MOV) and the results can be found at

Another way used by Kenneth Massey.

Jeff Sagarin is also in charge of SOS ratings.