Is Emilio Pagan the next Mariners relief ace?

The Mariners rotation sucks. (Don’t take my word for it — let the folks at Lookout Landing explain just how bad it is.) Seattle is still in the chase for an AL Wild Card spot for two reasons: The hitters are whacking the crap out of the ball, and the relievers are holding it together. To this point, the latter group ranks 12th in the majors in both fWAR and RA9-WAR, a solid showing that’s helped the team to its 66-64 record.

Nelson Cruz is taking the Raul Ibañez approach to life

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A pair of truly unique aging curves (yes, “pair” and “unique” contradict each other, that’s the point)

“Solid” isn’t quite living up to expectations — FanGraphs predicted the M’s bullpen would be eighth in MLB, thanks mostly to Edwin Diaz. As a rookie last year, he was historically great, notching a 2.79 ERA and 2.04 FIP in 51 ²⁄₃ innings. This season, though, he’s taken a step backward, with his ERA climbing to 3.51 and his FIP spiking to 4.26.

In this context, we now must evaluate Emilio Pagan. Like Diaz, he’s blown past the competition in his first big-league season. Over 36 ¹⁄₃ frames, he’s running a 2.72 ERA and 2.69 FIP. But as Diaz has demonstrated this year, a hot start to your career doesn’t guarantee you’ll keep dominating. What does the future hold for Pagan? Let’s look at the factors working in his favor, as well as those that could sink him.

The case for

A low ERA is one thing. Maybe a guy’s pitching well, or maybe his defense is bailing him out, or maybe he’s just getting lucky. In 36 ¹⁄₃ innings, anything can happen. A low FIP is a different matter — it’s usually a sign you’re doing something right. And Pagan, based on his strikeout and walk rates, is doing something right. He’s racked up 38 Ks while issuing just six BBs. Out of 202 relievers with 30 innings, his 23.2 percent strikeout-minus-walk rate is 26th, right between Felipe Rivero and Dellin Betances.

How do you avoid walks? Pound the strike zone. How do you strike hitters out? Get them to swing and miss. That combination is hard for many pitchers to pull off, but Pagan’s done it with ease. Behold, this poorly made graph:

Data via FanGraphs (Pitch Info)

Returning to that 202-man sample, we see Pagan ranks 40th with a 14.1 percent whiff rate, and fourth with a 55.7 percent zone rate. His ability to balance the two of these puts him in some elite company — as the unreadable labels on the graph show, he’s near two of the best closers in the game, and one of the more underrated relievers.

How has Pagan put up such impressive numbers? It’s all about his fastball. Pagan’s thrown his four-seamer 72 percent of the time this season, relying on a slider and a scarce changeup aside from that. For a pitcher to trust his heater that much, it has to be a pretty deadly pitch, and Pagan’s four-seamer definitely meets the standard. He’s thrown the pitch for strikes and gotten hitters to swing-and-miss at it:

At 93.8 mph, Pagan’s four-seamer is actually subpar in terms of velocity (the MLB average for right-handed relievers is 94.7 mph). But he gets a lot of rise on the pitch, which he amplifies by throwing it high in the strike zone:

Image via Brooks Baseball

While the heater occasionally catches too much of the plate, Pagan generally doesn’t put it where hitters do the most damage. The result is a ton of strikes, and a good amount of whiffs; that’s always a good 1-2 punch.

A reliever doesn’t need multiple pitches if he’s mastered one. Pagan is still working on his slider, and if he can develop that breaking ball to pair with his fastball, he might get even better. For now, he’s shown an ability to limit walks and pick up strikeouts when he needs them, setting him up for success.

The case against

Let’s start with the most obvious stuff. Pagan is a 26-year-old rookie who has pretty much no background as a prospect. Baseball Prospectus left him out of its writeup of the Seattle farm system, and FanGraphs’ Eric Longenhagen listed him in the “Other Prospects of Note” section. This is Longenhagen’s full blurb:

A righty reliever who works up in the zone with a fastball at 92-94 and throws an average slider, Pagan is in Triple-A but not on the Mariners 40-man and projects as middle-relief depth.

Not an inspiring prediction. Why were the prospect analysts so down on Pagan (aside from the fact that he was a 25-year-old in the minors)? If he has good control and strikeout stuff, what more could they want?

Ks and BBs aren’t everything. Some hitters will put the ball in play, and that’s where Pagan’s production could take a hit. This season, no other reliever has allowed more balls in the air:

Fly balls are a double-edged sword. On the one hand, popups and cans of corn are pretty easy to catch, so someone like Pagan can run a low BABIP — especially if he has an elite outfield defense behind him. On the other hand, fly balls can obviously turn into home runs, and the more hitters elevate, the more chances they’ll have to go yard.

The long ball hasn’t hurt Pagan to this point — he’s given up three in his 36 ¹⁄₃ innings — but that probably won’t continue. His exit velocity against is 88.1 mph; among 453 pitchers with at least 400 pitches this year, that’s the 72nd-highest. And Safeco Field has been more homer-friendly in recent years, ever since the Mariners moved the fences in.

By ERA and FIP, Pagan is having a stellar MLB debut. By xFIP (4.24) and DRA (4.46), he’s been more pedestrian. The low ground ball rate is why those other ERA estimators* are pessimistic about Pagan. With the probably juiced ball leading to more homers across the majors, we shouldn’t Pagan to be immune. All it takes is a few fastballs that aren’t high enough — or a high fastball that a hitter just decides to yank into the seats — and Pagan’s ERA goes up.

*Well, it’s probably why DRA is pessimistic. We don’t know.

With many of their stars aging and the farm system looking pretty barren, the M’s have a pretty narrow window to make a playoff run. Like Diaz, Pagan should help them get there, as he’s proved his worth at the big-league level. But Pagan won’t excel like this forever — while the strikeouts are nice, they can’t negate the absence of grounders. A reliable late-inning presence, he is; a relief ace, he is not.

Ryan Romano is the co-managing editor for Beyond the Box Score. He also writes about the Orioles for Camden Depot, sometimes. Follow him on Twitter if you enjoy angry tweets about Maryland sports.