term used, often in America Football, particularly College Football, in describing the difficulty of opponents a team has faced. The harder the S.O.S., the better as the team is more likely to be pardoned for losing games if they typically face better opponents.
Ohio State beat out Baylor and TCU to grab the fourth and final spot of the 2014 college football playoffs because Ohio State had a better strength of schedule as well as out of conference schedule. So though all three had lost one game each, the committee believed Ohio State's strength of schedule warranted them being awarded the final spot in the rankings.
by DuanCulo aka Duante Amorculo December 10, 2014