MLB's Ridiculous Obsession With Closers

What is up with the MLB's obsession with closers? Every team thinks they need one, but they don't. If a starting pitcher throws 8 great innings, why take him out? Although there's no rule that says you have to, managers act as if there is.

This probably cost the Oakland A's a win tonight. Jeff Samardzija threw 8 innings of 4-hit, shut-out ball, and with the A's leading 1-0, he was replaced in the 9th by the A's current closer, Sean Doolittle, who promptly gave up 5 runs in 1/3 of an inning pitched, and the A's lost 6-1. To be sure, Samardzija had thrown 116 pitches, but surely the A's could've at least allowed him to start the 9th, and then if he ran into trouble, they could bring in their closer.

But no. The A's are just as susceptible to the pressure of cultural norms as are other organizations. As the sociologist Mark Chaves notes in an entirely different context (Ordaining Women, pp. 32-33):

When an organizational practice or structure becomes commonly understood as a defining feature of a “legitimate” organization of a certain type, organizational elites feel pressure to institute that practice or structure. If there is a cultural norm that says, “In order for an organization to be a good organization, it must have characteristic X,” organizations feel pressure to institute characteristic X.

In professional baseball, having a closer is one of those institutional characteristics that organizations feel pressure to institute. However, as I noted back in March, most closers aren't as good as future Hall of Famer Mariano Rivera ("Not Everyone Can Throw Like Mariano Rivera"), and the failure to realize this, probably cost the A's the game tonight and may have jeopardized their chances of making the playoffs.