Stronger Than Ever, Quinn Priester Making Case as Playoff Starter for Brewers

Assuming they're both healthy, Freddy Peralta and Brandon Woodruff will start the first two games of the Brewers' playoff run, in the National League Division Series. At certain points throughout this season, it's looked like Jacob Misiorowski or Jose Quintana could take the ball for Game 3, but at this point, it's virtually a sure thing: On October 8, Quinn Priester will make his first career playoff start. 

Priester has gone through two rough patches during his otherwise stellar campaign. The first came in late April and early May, as he and the Brewers worked on things and inched toward the version of him that has been unlocked since. The second came in the middle of last month, when Priester limped through 14 total innings, gave up nine runs, walked seven and struck out just 11 of 65 opposing batters over a three-start stretch. The last of those appearances came August 21 at Wrigley Field, when the Cubs were unable to land a knockout punch but still pushed Priester out of the game in the fifth inning. The Brewers saw something that worried them enough, after that, to push back his next start until August 30.

Specifically, the concerning trend was a falling arm angle—a sign of the fatigue Priester is navigating as he pitches deep into a big-league season for the first time.

After eight days of rest and with some work behimd the scenes, though, Priester has come back with his deceptive combination of a high arm slot and a sinker-forward arsenal restored. In fact, his arm is so rejuvenated that in his start against the Pirates on September 5, he averaged better velocity on his sinker than in any start since June—and essentially his best velocity of the season.

The goal, now, is to keep Priester this fresh and strong for another six weeks or more. When he's throwing in the mid-90s, he's a very tough at-bat. In fact, as the Brewers have worked with him on a season-long evolution, he's become a very good mid-rotation starter. Of the other 11 likely playoff teams, he would start Game 2 (rather than Game 3) of a series for at least four or five.

The first rough patch Priester went through included the stretch in which he moved over toward the third-base side of the rubber, which changed the angles his stuff creates and helped unlock some of the other adjustments he's made this summer. To understand them a bit better, let's briefly compare a start from that period to the one he made last week against Pittsburgh. 

Here's an overhead look at the trajectories of his pitches to right-handed batters in his start on April 26, against the Cardinals.

The clusters of white dots show the (estimated) point at which the hitter can begin to readily identify pitches. The pink ones show the (estimated) point by which a hitter has to have committed and shaped their swing, in order to hit the ball. As you can see, there are two distinct groups within each, especially the pink dots. That's because, at that point, Priester was effectively a two-pitch pitcher to righties. He leaned heavily on his sinker and slider, and the velocity and movement difference on them gave hitters more ways to differentiate and attack them.

Now, here's the equivalent image for his start against Pittsburgh last Friday.

It's subtle, but start by noticing the difference in Priester's release point. The ball now leaves his hand a bit wide of the edge of the pitching rubber, because he's slid over to that side of the mound more since April. That creates different angles of travel for each of his pitches, from hand to hitting zone. Secondly, see how more of the white dots cluster closer to the plate? Again, the difference is small, but it's important. Because Priester is throwing a hair harder now than he was in April (and because of his pitch mix), he's giving hitters less time to identify and decide about pitches.

Finally, see that the pink dots spread much more evenly. That's for a simple reason: Priester went to his cutter and curveball much more often against righties while facing Pittsburgh last week than he had with St. Louis batters months earlier. He's closer to a four-pitch guy to righties, now.

Let's now step into the batter's box, and visualize what Priester is throwing the way a righty batter would. Here's an animation from a right-handed hitter's perspective of all the pitches he threw to Cardinals righties in late April.

Immediately, you can see how early the cutter's trajectory diverges from those of the sinker and slider. You can also see the slider standing out based on how quickly it falls off the plane the sinker holds. The sinker does veer back toward the righty batter, but from the angle Priester was working and with the mix he deployed back then, the sinker and slider didn't look much like one another out of the hand.

Here's the same look through the eyes of Pirates righties last week.

One neat thing about this style of animation is that it gives us a chance to clearly see how much moving on the rubber or changing an arm slot can affect a hitter's visual cues. The change in release point here means that Priester's sinker, slider and cutter all hold something close to the same initial trajectory. Actually, his curveball doesn't even pop out of the hand, the way it often can for pitchers like Priester.

Finally, let's zoom back to behind the plate and see where these pitches actually ended up. First, for the start against St. Louis:

Because of Priester's high arm slot and the mound position he was using then, he really couldn't make much use of the inner third of the plate against righties at the time. You also need a certain amount of velocity to confidently go into the kitchen of big-league hitters, and he didn't have the pitch up to speed at that juncture. He was very slider-dependent, and as you can see friom behind the plate, some of those sliders were easy takes for Cardinals batters.

Let's take a look at the same image for the Pittsburgh start.

It's much easier for the sinker to hit the inside corner now. Just as importantly, though, look how Priester now uses the cutter to attack the whole zone, rather than just skidding it off the outside corner. This makes it harder for the hitter to identify both the sinker and the slider, based on the way the three play off each other in terms of movement and speed. For good measure, Priester also threw 10 curveballs to righties in this last start, a new wrinkle that put them on the defensive.

There are a lot of things you can do to the Pirates lineup that won't work against, say, that of the Padres or Cubs come October. Priester can't stop evolving now. However, restored by his brief break last month, he's spun 13 marvelous innings over his last two outings. Working on extra rest yet again, his challenge Friday night against the Cardinals will be to keep honing his new, wider mix and to keep learning to balance pacing himself with cutting it loose. He's safely written into Milwaukee's October plans. He just needs to keep testing and learning, while resting and managing his body to be ready to throw 95 and fully deploy his repertoire when the lights get brighter.