The Stuff That Dreams Are Made Of: Atahualpa Severino

Many popular opinions of pitching prospects are formed from general scouting reports. While these reports are invaluable resources, they can’t always be trusted. Hundreds of minor league hurlers are credited with “mid-90′s velocity,” but very few MLB starters actually have that grade of heat, for example. It’s incredibly frustrating to hear about a pitcher with “a mid-90′s heater and plus curve,” only to have him come up to the big leagues and show a fastball that averages 90.5 mph and a slider.

When a pitcher come up to the majors, we can finally get a foolproof reading on what exactly his arsenal is comprised of, thanks to the great Pitch F/X system. In this series, I analyze just that–the “stuff” of recently-promoted MLB pitchers. Now that they’ve achieved their big league dreams and thus factor directly into the MLB picture, it’s high time that we know exactly what these guys are providing.

This time, I’m taking a look at Nationals reliever Atahualpa Severino.

26-year-old lefthander Atahualpa Severino made it to the majors with the Nationals as a September callup after striking out 38 batters in 32 innings in Triple-A. A short guy with a big but erratic arm, Severino also walked 23 batters in Triple-A–at his age, with that inconsistency, and just a fastball and a slider, he didn’t get much fanfare.

Still, though, Severino’s six-game, 4 2/3-inning audition with the Nationals was an unqualified success. He struck out seven batters and walked just one, allowing two runs on five hits, including one homer.

While he’s just 5’9″, Severino operates with a very high arm slot that gives his fastball explosive late life up in the zone. He works at 91-96 mph, and constantly is trying to climb the ladder with the pitch:

Incredibly, just 12 of those pitches did not go for strikes, as batters had a tough time laying off of Severino’s high heat. Overall, they chased 44.6% of his out-of-the-zone pitches. The only pitcher in baseball to have a higher rate was the A’s Neil Wagner, and while it’s an incredibly small sample, it’s also a very positive sign for Severino.

In the 35 swings they took against Severino’s fastball, batters only managed to put the ball in play nine times, whiffing on four swings and fouling off 22 pitches. Clearly, the explosive movement on the pitch makes it tough to square up, and it’s obviously hard to drive a pitch that’s above the shoulders.

Severino’s second pitch is a sharp slider in the 81-85 mph range. Like the fastball, he doesn’t put it in the strike zone, except in this case he breaks it off the plate away to lefties:

Just 11 of the 23 sliders he threw went for strikes; three were swinging strikes. Just two were put in play.

Overall, there’s no doubt as to why Severino walked a ton of guys in Triple-A–he throws a ton of pitches outside the strike zone. Only 34.9% of his pitches were in the zone, one of the lowest rates in baseball, as he’s constantly throwing the fastball too high and the slider too far outside.

The flip side of that wildness is that both of Severino’s pitches are very good, which helps him rack up the strikeouts and avoid hard contact. Batters seem to like swinging at his pitches a whole lot, and that results in a lot of foul balls.

What does that mean for Severino’s future? Well, he’s a classic NL lefty specialist, where his stuff is very effective at getting strikeouts and preventing hits. The big negative is that he’s probably going to give up a lot of walks, but that’s tenable if he’s spotted carefully. Imagine Aroldis Chapman‘s 2011 with slightly less velocity, and slightly fewer strikeouts and walks, in fewer innings–that’s what Severino’s upside is. He could be a nice asset if put in situations he can succeed in.

For more on the Nationals, check out District On Deck.

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