during the season, and those are dictated far more by what the team is ranked when you beat them than how a team finishes up. In 1984 BYU beat #3 ranked Pitt and jumped big in the polls. Nobody really cared much at the end of the year that Pitt didn't finish great, at least it didn't impact BYU in the polls - the gain for beating Pitt had already been realized that week.
Is this difficult to understand?