What in the world is Dane Dunning cooking?
The Rangers' sinkerballer is doing something much different in 2024, with questionable results.
Baseball is a game of adjustments. More than that, it is often a game of re-invention. Once you get to the big leagues, the things that have worked for you throughout your career could fail at any moment. Major league players are really, really good, and the key to sustained success is adaptability. Whatever weakness you possess, MLB competition will find it. As a pitcher, it’s not enough to do one thing well and spam it over and over again, unless you’re Mariano Rivera. Hitters will eventually adjust to your strengths, and a counter-adjustment must be made in response.
For most of his career, Dane Dunning’s bread and butter has been the ground ball. As a sinkerballer with unimpressive velocity (hovering around 90 MPH with the heater), Dunning has relied upon the sinking fastball to generate weak grounders as a means of compensation for his lack of swing-and-miss viability. Sure, Dunning mixes in a solid slider and changeup to keep hitters off balance, but all of that has been secondary to inducing ground balls with the sinker.
During Dunning’s first two seasons in Texas, he was elite at what he did. In 2021, he posted a 54.2 % ground-ball rate, good for the 91st percentile in the Majors. In 2022, that number remained steady at 52.8% (89th percentile). However, despite his proficiency in keeping the ball on the ground, Dunning didn’t achieve particularly effective results. His 4.51 ERA in 2021 and 4.46 ERA in 2022 left a lot to be desired. According to his cumulative ERA+ during this time, Dunning was basically a slightly below-average pitcher. Not terrible for a fifth starter, but definitely at risk of being replaced.
And replaced he was. The 2023 signings of Jacob deGrom, Nathan Eovaldi, and Andrew Heaney pushed Dunning to the bullpen, where he excelled before eventually re-joining the rotation and winning the Rangers Pitcher of the Year award. It was last year that Dunning seemed to have adjusted a bit. His ground-ball rate fell to 47.2%, and his fly-ball rate increased by nearly the same delta. Despite the uptick in fly balls, Dunning posted a career-low HR/FB rate, while his strikeout and whiff rates actually fell year-over-year between 2022 and 2023. So, Dunning traded some grounders for fly balls and had good luck with that. He walked fewer guys and limited barrels, culminating in the best season of his career.
But despite the improved results, Dunning’s FIP (a stat that eliminates defense from the equation) and xERA were right in line with his career averages. It’s pretty apparent Dunning benefited from a bit of luck, even though he made a small adjustment. So, another change was likely needed to sustain or build upon the success of 2023.
Well, so far in 2024, that change has arrived in a massive way. Dunning has been unrecognizable from the guy we saw early in his Ranger career. The velocity and pitch mix have remained the same, but how Dunning is going about his business is drastically unlike anything we’ve seen from him before. Dunning, whose previous career-high strikeout rate of 24.6% came in the pandemic-shortened 2020 season, is striking out 28.9% of batters faced in 2024. This is good for the 81st percentile in all of baseball. His whiff rate sits at 33.1% (88th percentile), a career-high by nearly six percentage points. Dunning is generating more swing-and-miss than he ever has, by an incredible margin.
On the other side of the coin, Dunning’s ground-ball rate has continued its trend from 2023 by dropping again. It’s down from 47.2% to 44.2%— still above average, but barely. At first glance, it looks like Dunning is trading some grounders for strikeouts, which is all well and good. However, if we look at Dunning’s fly-ball rate, we start to run into some glaring issues.
So far in 2024, Dunning is posting a career-high fly-ball rate of 39%. And, unlike 2023, he has not had good luck avoiding the home-run ball. His current HR/FB% of 23.3 is over eight percent greater than his previous career high. Dunning has surrendered seven homers in 32.2 innings, tied for third in the Majors. And it’s not like he’s been unlucky with wall-scrapers.
Dunning is getting absolutely hammered when hitters put the ball in play. His average exit velocity is 92.7 MPH, the third percentile. Dunning’s barrel percentage of 16.9 is THE WORST IN BASEBALL among all qualified pitchers. Any way you want to slice it, Dunning is giving up loud, loud contact. It isn’t sustainable and helps explain the difference between his 4.13 ERA and 5.30 FIP.
So, why is Dunning having so much trouble with hard contact? Well, it all comes back to “ol’ reliable,” the sinker. So far in 2024, opposing batters are slugging .500 against the pitch, with an xSLG of .615. His other pitches have basically been untouchable. Almost all of the damage is coming off the sinker. And the problem with the sinker? It doesn’t appear to be sinking properly. While the sinker is still generating good vertical break, its horizontal break has been bad and. And despite the pitch’s good vertical movement, it’s still not finishing beneath the zone enough. Below is a Statcast illustration of all the sinkers Dunning has thrown so far in 2024.
That’s not a lot of balls finishing below the strike zone. Most of the pitches seen here are up and/or middle. And when you throw 89-91 MPH, that’s a bad place to be. It explains why the ground-ball rate is a career-low and why the fly balls and homers are skyrocketing. Put simply, Dunning needs to get the ball down and out of the middle of the plate.
I don’t know if Dunning’s suboptimal sinker location is directly correlated with his increase in whiffs, but that appears to be the case. His whiff rate on the pitch has doubled from eight percent in 2023 to 16% this year. What do we do with that? It’s an objectively good thing that Dunning is missing more bats, but the contact when he doesn’t cannot continue to be this damaging. The hope is there is a happy medium here, a place Dunning can get to where he can still get swings and misses with the sinker while limiting how often he leaves it up. That’s easier said than done, but he has to try.
If Dunning can sustain the success of his off-speed stuff while improving the sinker location, we may end up seeing a special season from the right-hander. But if it continues like it has so far in 2024, the bottom will fall out. During his last start against the Reds, Dunning gave up just three balls with exit velocities above 95 MPH while generating 18 swings and misses. You’ll take an outing like that every time; hopefully, that performance is a sign of things to come.