In sports, strength of schedule (SOS) refers to the difficulty or ease of a team's/person's opponent as compared to other teams/persons.
For instance, from 1992 to 2011, of 1,874 college athletes who entered the NFL, roughly 31% came from the SEC compared to only 0.64% from the MAC-EAST conference.
Major League Baseball (MLB) has a more extreme way of scheduling since interleague games are done rarely[needs update], and were only introduced in 1997, plus the fact that interleague games do not exactly have concrete rules, save for the number of rest days and doubleheaders.
In the National Hockey League, prior to 2008, some teams did not meet each other in a given year, and intra-division games are more frequent (six times) when compared to the NBA.
A strong team in a weak division or conference is capable of bloating their record in order to have a better seeding in the playoffs.
The playoffs may also award a home advantage to a team with a superior record, regardless of their SOS, although the NFL holds its championship game at a predetermined site, while MLB awarded home-field advantage in the World Series to the team representing the league that won the All-Star Game from 2003 to 2016.