Every season, the Rays want to have as sizeable a margin between the two as possible. Last season, that number dwindled to plus-2 as Tampa Bay scored 644 runs while allowing 642.
While that difference represented a plus-13 turnaround from the previous season, it paled in comparison to 2013, when the team was plus-54, and 2012, when it had a plus-120 differential. The Rays' all-time best run differential came in 2010, when the team posted a plus-153.
Given the Rays' prevention side of the equation in 2015, the run differential should have been greater.
Going back to 1984, the two AL teams that have allowed the fewest runs in a full season and finished below .