Bullpens, and bullpen arms are often best known for their volatility, a certain instability from season to season that is confounding. The Indians 2018 season was just that, confounding. A bullpen that was integral to great 2016 and 2017 seasons was suddenly a penetrable weakness as Cody Allen and Andrew Miller went from elite back end relievers to pumpkins.
The 2019 Indians bullpen had potential; there was the elite Brad Hand who remains dominant, the righty specialist Adam Cimber, the lefties matchup guys Tyler Olson and Oliver Perez, and finally a few lotto tickets like Nick Wittgren.
The Indians traded for Wittgren with little fanfare, and little acquisition cost in the form of command challenged Jordan Millbrath. What came next?
Wittgren is 14th in K%-BB% at 28.8% and 9th in FIP among qualifying relievers, he has been absolutely dominant over 16 innings. Yet, discerning the sustainability and underlying inputs is difficult.
Top end velocity is certainly not the only valuable tool for relievers but it is a boon; Wittgren averages just 92.1 MPH with his fastball, 39th percentile fastball velocity. His fastball spin rate is even more below-average in the 22nd percentile.
What is more, there does not appear to be a significant change in usage rate. Wittgren is using his fastball more frequently and a little more slider but nothing pops out.
Time to talk about what Wittgren has done well; and what he hasn’t. Wittgren is posting an 86th percentile K% of 30.5%. Wittgren is also mitigating exit velocity, leading to a hard contact rate in the bottom 10 percent of big league pitchers.
The questions raised; what exactly has changed for Wittgren? Is his level of performance sustainable?
In an effort to answer the first question; a big part of it comes down to command/control. Look below for Nick Wittgren’s curveball location prior to 2019:
What you seems a solid chunk of curveballs to RHH staying in the zone and roughly 45% of curveballs buried down to RHH. Whereas, in 2019 58% of curveballs are buried down outside of the zone to RHH:
The location changes do not only apply to his curveball. In the past, Wittgren’s fastball has frequently hovered heavily in the bottom two-thirds of the strike zone.
In 2019, Wittgren has thrown to the upper third of the strike with the fastball against RHH far more frequently.
In totality, Wittgren is throwing his fastball up in the zone more frequently, in the center of the zone less frequently, and his curveball is below the strike zone more frequently.
Wittgren is essentially expanding the zone vertically, challenging hitters up with his fastball where the effective velocity is higher, and burying the curveball down where it cannot be punished. A lethal combination.
Here, we appear to have a root cause, Wittgren is playing up his middling stuff by locating it efficiently in such a way that the pitches better play off each other.
The concept of sustainability is more difficult. Wittgren has improved but can he continue to command the ball at this level? Possibly but there is little certainty. Further, the batted balls, Wittgren has a fortunate level of success on batting average on balls in play despite near league worst exit velocity against, which suggests that even if command sustains batted ball outcomes will regress.
Through 16 appearances, Nick Wittgren has been more elite reliever than average reliever. Where his most probable outcome lies is closer to the latter than the former, but after a disastrous 2018 for the Indians bullpen, Wittgren being merely competent is enough.
Categories: Cleveland Indians