Jacob Misiorowski heads into his Jacob Misiorowski World Series Decision with a real question hanging over the start: can he get his slider command back to the level that made it such an important pitch for him earlier in the year? On Wednesday night, he is scheduled to take the mound for the Milwaukee Brewers in Game 5 of the World Series, but the numbers suggest the pitch that helps hold everything together has slipped in the playoffs.
That matters because Misiorowski has never been a conventional pitcher. He has the biggest fastball in baseball and still throws super, super fast, but the fastball is not the whole story. For him, the slider appears to be the pitch that keeps the rest of his delivery in line, which makes its recent drop in effectiveness a significant concern at exactly the wrong time.
Why the slider matters so much
Misiorowski said in the spring that the slider helps him find his release point and iron out his fastball mechanics. He put it simply: “Everything kind of plays well off of the slider.”
That is a revealing admission. Most pitchers lean on the fastball as the foundation, but for Misiorowski the slider may be the core of the arsenal, the pitch that helps make the others work. When he is landing it, he can stay organized mechanically. When it goes away, the rest of the mix can start to drift with it.
He expanded on that idea by saying: “I always have that to get me back in line of like, ‘OK, this is what my delivery is doing wrong. I’m getting a little too long.’”
That explanation fits the way his year has unfolded. At every minor-league stop, Misiorowski had double-digit walk rates. When he reached the major leagues, he ramped up his slider usage and posted the best walk rates of his career. The pitch was doing more than just missing bats; it was helping him repeat his delivery.
The playoff dip has changed the picture
In June, Misiorowski had his best month for slider locations, and the visual evidence backed it up. Using Baseball Savant and the Location+ model, his locations were at their sharpest then. In the playoffs, though, that command fell to the second-worst level of his year.
That is where the concern comes in. If the slider is the pitch that corrects the delivery, then a drop in command can quickly become a wider problem. The Brewers are still getting the benefit of Misiorowski's explosive fastball, but the pitch mix changes when the slider is not landing in the right spots. More fastballs can follow, and that can make him easier to sit on if he cannot keep hitters honest with the secondary stuff.
The key question for Milwaukee is not whether Misiorowski has enough raw stuff for a World Series start. He clearly does. It is whether he can make the slider work early enough to keep his mechanics clean and stop the game from becoming a fastball-heavy grind.
For a pitcher who has already shown that the slider can settle him, that may be the difference between surviving Game 5 and controlling it.
