On the Importance of a Closer

It must have annoyed Ranger fans to hear the ESPN team gushing about Mariano Rivera last night as he closed out the ninth inning of a Yankee win. Even I felt that they were a little over the top.

A reliever is such a small part of a team- his 60-70 IP make him exponentially less valuable than a starter, and conventional wisdom is that any pitcher will see improved results with a move to the bullpen.

This is true when those 60 innings are examined in a vacuum, in the context of a season's worth of data: over 1400 innings of work.

But baseball is a race against 27-outs, and those last 3 outs can have a disproportionate influence on a team's record, and in turn, the team's playoff chances. For teams in the hunt, a few wins and a couple losses means all the difference in revenue, in marketing, and in a chance at a ring.

3 wins against their rivals, and the Braves could have tied the Phillies in 2010, the Padres could have sent the future World Series champs home for the winter, the Red Sox could have had the Wild Card, or the Twins could have faced a play-in game against the White Sox.

In Mariano Rivera's time as closer, the Yankees have rarely underperformed their Pythagorean Winning Percentage, and he's the reason why. The way to beat (or underperform) a Pythag Record is to win (or lose) more than your share of one run games.

Already in 2011, the Yankees are one game up on the Pythag, thanks to their explosive offense and their brilliant closer (and his less brilliant but still valuable set-up men).