Bullpenning takes on a new meaning in October, when starters are yanked in the blink of an eye and relievers are asked to carry the load.
So which teams are best positioned for the postseason?
Heading into the weekend, the Brewers bullpen ranked first in the majors during the month of September with a 1.84 ERA, followed by the Dodgers (.251) and Indians (2.65).
The Brewers pen is led by left-hander Josh Hader, who came into the weekend series against the Pirates having struck out 17 of the last 20 batters he faced over his last four appearances, allowing one hit over six innings. But Hader has worked back-to-back games only twice since the start of August as manager Craig Counsell makes sure his arm gets a rest.
Hader is a closer-in-waiting, but he can come in at any point and pitch multiple innings, already having made 22 appearances of two or more innings.
"Craig has done a tremendous job of using him at various points in a game that we think are high leverage," Brewers general manager David Stearns said. "And sometimes that's going to occur at the back end of games, and sometimes it will occur in the fifth inning. And when it occurs in the fifth inning, we're not afraid to use him there."
The three worst bullpens in September among playoff contenders were the Braves (5.29 ERA), Cardinals (5.06) and Reds Sox (4.48). The Red Sox have a reliable closer in Craig Kimbrel, but their middle relief could be their Achilles heel in October.
