Jimmy Nelson is Spinning Heads

The last few years have been a series of unfortunate events for Los Angeles Dodgers‘ pitcher Jimmy Nelson. After missing a portion of 2017 and all of 2018 due to a rotator cuff and partial anterior labrum tear, Nelson was non-tendered by the Milwaukee Brewers. The Dodgers signed him to a one-year deal in 2020, but again Nelson was hit with bad luck and missed the season because of a lower back surgery. But fortunately for both parties, the Dodgers re-signed Nelson to a minor league contract. The former second round draft pick and Brewers’ top prospect was once discussed as the potential ace to a big league starting rotation. But after 617 innings as a starting pitcher left him with a 21.0% strikeout rate, 4.24 ERA, and 4.10 FIP, the Dodgers decided to try him in a new role—relief pitcher.

Nelson has thrown 16.2 innings as a reliever with a 35.2% strikeout rate, 2.05 xERA, and a .131 xBA. By Statcast percentile rankings here’s how he looks.

He has an issue with walks, falling in the 11th percentile by walk rate, but his pitches are garnering a ton of whiffs, strikeouts, and positive results. Additionally, xwOBAcon puts Nelson falls in the top 4% of the league, so although his barrel and hard hit suppression aren’t elite, his overall contact control has been. All of this is to say one thing: Nelson has been pitching really, really, well in his new role. And although it’s possible that Nelson naturally became better in a relief role, I think there’s more to it than that. I think it’s possible that the Dodgers, or whoever Nelson is working beside, have helped him reach another level.

 

Spin, Spin, Spin

 

For most of his career, Nelson has had middling spin rates for both his fastball and curve. But, both pitches took a step forward in 2019, where his fastball spin placed him in the 76th percentile and his curve spin placed him in the 86th percentile. And this season he has found even more spin.

 

 

The lines are pitch spin rates prior to his string of injuries. The three dots at the far right of the chart are what we’re interested in. Nelson is seeing a near 200 RPM jump for all of his pitches. So much so, that he is now in the 96th percentile by fastball spin and 92nd percentile by curveball spin. His slider saw the biggest jump in average spin, improving by 199 RPM. By active spin, his curveball and slider are both in the 88th percentile, and his fastball is in 92nd percentile. These are massive improvements that are effectively contributing to better movement on two of his pitches. Let’s take a look at how these higher-spin pitches are moving:

 

 

For horizontal movement, Nelson is finding about an half inch more of movement on both his slider and curve. His fastball is getting less movement, but the horizontal movement it gets is not very important. As far as vertical movement goes, Nelson is finding more than an inch of rise on his fastball, almost an inch and a half of sink on his slider, and about .75 inches of extra sink on his curve. His spin is inducing movement on his off-speed pitches that is nearly polar opposite of the movement on his fastball. While his spin-based movement on his fastball lives from the 12-2 range, his slider and curve is getting spin-based movement primarily in the 7-9 range, creating quite the split between pitch velocity and movement.

Although there are some usage and location changes that we will be getting to, the extra spin and movement has undoubtedly aided Nelson this season. Here’s how his pitches have performed so far.

 

Pitch Usage/Location

 

I alluded to it above, but improved spin and movement aren’t the only improvements Nelson has made in his relief role. As a starting pitcher, Nelson’s arsenal primarily consisted of a five-pitch mix. But in 2021, Nelson has dropped his sinker and changeup completely. The changeup isn’t all that important, because it was always his least thrown pitch, but the sinker used to be Nelson’s primary fastball.

Each year Nelson has thrown his sinker less and less until it completely disappeared from his mix. On the other hand, his curveball and slider are being utilized at a career high and Nelson is relying on his four-seamer as his only fastball. Nelson’s sinker had a career .364 wOBA and .357 xwOBA, so ditching it in favor of an elevated fastball was a smart decision. Instead of living at the bottom of the zone with his sinker, which did not have plus movement, Nelson is opting to throw his rising fastball at the top of the zone. As a result, hitters are hitting .111 against his elevated fastball.

 

 

The approach with Nelson’s curveball and slider have stayed the same. From a righty batter’s perspective, he mainly throws both pitches down-and-in. Nelson’s location adjustments have led to a career low in line drives and a career high in pop-ups.

Nelson currently has the 10th best xERA and xwOBA. Again, walks are still an issue for him, but he’s making all the right changes to turn himself into a great reliever. His pitches are spinning and moving more than ever before, he’s solidified his arsenal with three plus pitches, and he’s seen a huge uptick in punch-outs. Are these changes enough for Nelson to become elite in the role? I guess we will have to wait and see.

 

(Photo by Brian Rothmuller & Frank Jansky/Icon Sportswire | Design by Michael Packard (@designsbypack on Twitter @ IG)