At this point in the year most contending teams have solidified the front of their starting rotations and have a single effective closer. And whiles aces and closers get the glory, almost equally important for contending clubs is how well their seventh- and eighth-inning relievers perform in the final weeks of the regular season. Being effective in these two innings has been critical for several teams contending primarily for wild-card berths. For example, Oakland has led baseball in seventh- and eighth-inning ERA this year with a 2.15 ERA in both of those critical innings.
It should come as no surprise that the top seven teams in seventh-inning ERA would all make the playoffs if the season ended today (see chart at right). Similarly, when we look at eighth-inning ERA, the top seven teams are all within 2.5 games of the playoffs.
Statistics through five months of baseball certainly offer an adequate sample size to come to some preliminary conclusions. However, pitching under the daily pressure of a pennant race can skew projections and predictions. Experience, health, schedule, competitiveness and makeup often become significant factors in the final leg of any pennant race -- especially to relievers pitching in high-leverage situations.