During the latest Banished to the Pen podcast, we had a discussion on the Craig Kimbrel trade and the question of where we are on the spectrum of overvaluing or undervaluing closers. If you haven’t listened yet, you really should. Two out of the three guys on it are funny and know what they’re talking about, the other not so much.

Anyway, it got me thinking about the nature of closers, and how they are being utilized in both the Major and the minor leagues, and how that has changed over the years (if at all).

First of all, I wanted to see if closers are being used less now than ever before. Observationally, it seems like they are being called on to get fewer outs than 20 years ago, but I wanted to look at the hard data to see if that was truly the case. So as not to skew the numbers, I pulled the top ten relievers each season by number of saves (since I wanted to make sure I was looking solely at closers).

Indeed, you can see the average innings pitched per appearance has trended downward since 1995. In fact, 2015 was the low-water mark in the last 21 seasons, as the top ten closers threw only 0.97 innings per appearance.

But looking a little closer at the data, the difference between 1996 (the highest average) and 2015 is a decrease of only 0.1 inning per appearance. In other words, closers are pitching one fewer inning every 10 outings (or, to put it in handier baseball units, recording one fewer out every three appearances). Extrapolate that out, and you’re looking at closers throwing only six or seven fewer innings per season now.

So while the trend is obviously headed in a certain direction, it is not a dramatic change from 20 years ago.

Next, I looked at all relievers that recorded at least 10 saves in a season for the same time period. As before, the 2007 season marked a turning point for closer utilization. Since then, more and more relievers are averaging under an inning per appearance—peaking in 2012, when 29 of the 37 relievers recorded less than three outs per outing on average.

Another factor driving that number lower and lower is that the specialization of relievers has trickled down to the minor leagues and colleges. More pitchers are closing in the big leagues now that have done nothing but relieve in the minor leagues (or even, in some cases, before that).

Pitchers like Drew Storen, who were once an anomaly, have now become the norm. Storen was solely a reliever in college, and threw only 53 2/3 minor-league innings before making his MLB debut. The most innings the right-hander has pitched in a professional season: 79 2/3, between his sophomore season at Stanford and his first year in the Nationals’ organization.

Even if front offices and field staffs want to begin using closers longer in games, the data suggests that pitchers are now conditioned to work three outs and rarely more. Because of that, the next step in reliever usage doesn’t appear to be calling on the Aroldis Chapmans of the world for more than one inning during the majority of the season.

Instead, the real sea change will happen when managers begin using their closers in the highest-leverage situations late in the game—regardless of conventional baseball thinking or contract incentives that reward saves.