Twins Daily: Bad sliders: What happened to Trevor Hildenberger last season?

Twins Daily's Matt Braun breaks down the side-armer's rough 2019 season.
Publish date:

Countless pitchers through the years have proved that there are many ways to get a hitter out. Not everyone can be Gerrit Cole in the way that he just obliterates batters with a bazooka fastball. For Trevor Hildenberger, it seemed that he found a schtick that could work in the majors until suddenly, its effectiveness ended.

Now, this is where I must admit that I am heavily biased towards pitchers that throw sidearm/submarine. I love the somewhat goofy dichotomy between the ultra serious hitter and the dude on the mound scraping his knuckles on the ground in order to be as effective as possible. 

Plus, it seems like they all have cool names (Darren O’ Day, Chad Bradford, Dan Quisenberry, you get the idea). Enter Trevor Hildenberger, who entered the big-league scene in 2017 and did this do the first batter he faced: 

You can bet that I am now fully invested in his future at the big league level.

Hildenberger was astounding in 2017. Rarely do you see a reliever with an elite groundball rate (58.8%) and great peripherals (2.92 xFIP). Hildenberger was in the top 15 for relievers with at least 40 innings pitched in 2017 for both of those stats respectively and it seemed like the Twins had a future elite reliever.

Two-thousand-eighteen started in a similar way for Hildenberger as he held a 2.06 ERA in late June and had only allowed more than one run in a single outing just once. That is, until the game from hell on June 30th. 

Recall, if you will, the series against the Cubs in 2018 where Willians Astudillo made his major league debut, every game ended up in a shootout, and heat-related illnesses turned Minnesota's starting outfield into Logan Morrison,Astudillo, and Robbie Grossman. Beyond that butcher of a defense was a nightmare outing for Hildenberger in which he walked four batters, gave up four hits, allowed five earned runs, and only got one out. His ERA on the season shot up from that 2.06 mark to 3.18 and he hasn’t been the same pitcher since.

It would be dramatic for me to imply that a single outing was the turning point in a career but perhaps the outing was more of a symbolic pivot in which the Cubs became the first team to make it apparent that Hildenberger was beatable. 

The numbers are incredibly eye-opening as in 81 ⅓ major league innings before the outing his ERA/FIP/xFIP slash line was 2.66/3.44/3.26, and his groundball rate was 54.5%. Starting with that outing through his most recent appearance Sept. 21, 2019, his slash line becomes 9.72/5.12/4.41 with a groundball rate of just 40.9% over 50 innings.

I think I speak for most Twins fans when I ask: “What the hell happened?"

The first thing to look at is his pitch mix which is a fairly standard sinker, slider, and changeup combo, with the occasional over-the-top four-seam fastball to keep hitters on their toes. 

His slider has never been that good by pVAL (pitch value) but his sinker/changeup combo was what allowed him to be dominant to start his career, which leads me to believe that that combo has gotten worse. His changeup pVAL was still elite in 2018 but his fastball quality went into the toilet despite gaining a small tick of velocity. Why could this be? Well, let’s take a gander at some heat maps:


There’s a significant shift to the outside of the plate versus righties and inside against lefties. The general stereotype is that lefties love it down and in and perhaps throwing more outside to righties allows them to get extended and hit the ball harder than when he was going inside earlier in his career. 

Granted, this may not be the thing but it certainly is a thing, as pitching is more complicated than a single pitch losing location.

No matter what, Hildenberger does not have much room for error if he wants to continue his major league career. He’ll likely start the year at Triple-A and be one of the first arms called upon when the inevitable bullpen shuffle occurs, but any success is far from guaranteed and all anyone can hope for is that the Trevor Hildenberger of old is still somewhere in there.

This story originally appeared at Twins Daily and was re-shared through a collaboration with Bring Me The News.

Next Up