Sports schedules come in two broad types: temporally constrained
schedules and temporally relaxed schedules. In a
temporally constrained schedule the number of slots, or
time periods in which a game may appear, is equal to the
number of games that each team must play plus any necessary
byes for leagues with an odd number of teams. For
instance, a double round-robin tournament has every team
play every other team twice: once at home and once away.
Such a tournament among 9 teams requires at least 18
slots. A temporally constrained schedule has 18 slots available.
A temporally relaxed schedule has more than 18
slots, and perhaps significantly more.