Spencer 2: Judgment Day

It’s the oldest story in baseball. The Braves took an athletic, hard-throwing, but undersized college pitcher named Spencer sometime after the first round of the draft. Even though said pitcher had done most of his collegiate work out of the bullpen, Atlanta stuck him in the rotation. And after only 20-odd starts in the minors, Spencer is in Atlanta’s major league rotation and a candidate to throw high-leverage innings — possibly even to start — in the playoffs.

OK, maybe it’s not the oldest story in baseball, but it’s happened twice now in the span of three seasons. And that’s where the paths of Spencer Strider and Spencer Schwellenbach diverge. Strider is what you’d get if a traditional power closer could throw 180 innings a year. (Well, if he could throw 180 innings in one year. We remember what happened a couple months ago.) It’s a hard fastball, and then a wicked slider. Pick one, because there’s no way for a hitter to cover both.

Schwellenbach also boasts mid-to-upper 90s fastball velocity, but unlike his teammate and fellow Spencer, he has one of the most varied repertoires in all of baseball.

Schwellenbach throws six pitches: a four-seamer, sinker, cutter, slider, splitter, and curveball. He’s thrown each of them at least 100 times this year, but none more than 400 times. Out of 156 pitchers who have thrown 70 or more innings this year, only one in 10 throws six pitches at least 5% of the time; Schwellenbach is among them. His most commonly used pitch is his four-seamer, which he throws 27.4% of the time. Strider threw both his fastball and slider more frequently in both of his major league seasons.

Schwellenbach has three pitches with arm-side movement in his four-seamer, sinker, and splitter. His two breaking balls have glove-side movement, and his cutter is basically neutral. Rounding to the nearest integer, he’s thrown at least one pitch at every radar gun reading from 75 to 99. He can throw anything, anywhere, at any time.

“I think it just makes the hitter clueless of what’s coming in different counts,” Schwellenbach said. “They’re not really expecting one pitch when I can throw six of them and command six of them.”

And here’s the really interesting thing about Schwellenbach: His entire arsenal is on the table most of the time. A lot of guys learn to throw this many pitches so they can effectively become two different pitchers based on which side of the plate their opponent is batting from.

One of the few pitchers who combines Schwellenbach’s fastball velocity and kitchen sink-iness is Phillies ace Zack Wheeler. Wheeler throws his four-seamer to everyone, but against righties, he goes sinker/sweeper for his secondary pitches. Against lefties, he throws a cutter, a curveball, and a splitter.

Schwellenbach throws five of his six pitches to everyone:

The exception to this rule is the splitter, which Schwellenbach uses heavily against lefties but ditches in favor of increased slider usage against righties. Which is understandable; not many pitchers throw a ton of changeup-type pitches to same-handed batters. Schwellenbach said he started out throwing his cutter only to lefties and his slider to righties, but he eventually got comfortable throwing both to everyone. And you see the results.

There wasn’t much of a book on Schwellenbach when he got called up. As he explained to David Laurila back in June, Schwellenbach was a shortstop through college, having dropped pitching and picked it back up more than once through his amateur career. He ended up playing both ways — shortstop and closer — his junior year at the University of Nebraska, and was one of the top relievers in the country even though his UCL was about to let go.

With all due respect to the hitters of the Big Ten, a closer who throws in the upper 90s doesn’t need six pitches to get hitters out there. Indeed, Schwellenbach’s writeups on the Braves prospect list as recently as 2023 have him down as fastball, slider, splitter (or changeup). So where’d the other half of the repertoire come from?

“June of last year, I started throwing a curveball as my fourth pitch,” Schwellenbach said. “In the minors, I added the cutter, but didn’t really throw it much until I got to the big leagues. Then I started working on a sinker once I got up here, just to have a pitch that goes arm side, to switch up the hitter’s view and help me with different sequences. I kind of put myself in a situation where I could throw any pitch if needed.”

Seeing as how Schwellenbach grew up in Saginaw, Michigan and became a two-way player in the Big Ten, I mentioned what a monster Jake Cronenworth was during his time in Ann Arbor. (Any conversation with me that lasts longer than five minutes is in some danger of turning into a conversation about Cronenworth at the 2015 Big Ten Tournament.) Having recruited by both Michigan and Michigan State, Schwellenbach was more interested in Cronenworth’s college career than most people I talk to, though he said he was more interested in the major league game growing up.

Nobody’s perfect.

Anyway, I bring this up because Schwellenbach… still kind of throws like a shortstop:

It’s a loose, whippy, low three-quarters arm action. It’s the angle infielders throw from when they want to show off.

“When I started pitching again in college, it was just like lifting my leg and throwing exactly how I was throwing from the infield,” Schwellenbach said. “I’d just field the ball and let it rip from down there, at all different angles. I think that’s where my arm slot came from, and I’ve stuck with that the whole time.”

Schwellenbach can throw comfortably from that angle. And, it bears repeating, he can throw hard; his average fastball velocity is 96.1 mph, which would be fifth among qualified starters if he had the requisite innings. He’s also, mercifully, avoided the command issues that can plague young pitchers. Schwellenbach’s walk rate in the majors is just 5.0%, and he’s only walked 53 batters in 234 1/3 competitive innings since high school.

According to Schwellenbach, if he could hit a target from 120 feet away with that arm action while playing shortstop, hitting the strike zone from half that distance ought to be a piece of cake. And so far it has been.

But that arm angle complicated things as he’s added pitches.

“At first it was really difficult — especially with the cutter — to get the ball to spin correctly and throw it in the low 90s. You know, not have it turn into a hard slider,” he said. “Then with the slider, I had to focus on the seam shift instead of throwing it at, like, a two o’clock spin to gain movement. It took me a while to figure that out too.”

Schwellenbach said he practiced those two pitches all offseason in order to get them game-ready. “Some days I threw too much because I was trying to figure stuff out.”

The other thing about a low arm slot is that the ball starts way farther to the pitcher’s arm side than it would in a more over-the-top delivery. Schwellenbach is a pretty compact 6-foot-1, 200 pounds; physically, he still looks like a shortstop or a third baseman. With relatively short levers, there’s none of the Chris Sale or Nick Lodolo effect, where every pitch that comes out of his hand looks like it’s going to nail a same-handed batter in the numbers.

But the pitcher’s starting position on the rubber becomes an important factor with so much sideways movement, whether he’s built like Darren Sproles or Manute Bol. And that became an issue for Schwellenbach in his first few starts.

When Schwellenbach got called up at the end of May, he was pitching from the third base side of the rubber, and in his first five appearances, he allowed a 5.40 ERA and a .265/.327/.441 batting line. He also walked seven batters and hit three others in just 26 2/3 innings.

“When I started throwing my sinker, I felt like I had to throw it like a foot in the left-handed batter’s box,” Schwellenbach said. “When I threw my four-seamer, I just aimed it right down the middle, and when I threw my sinker, I had to throw it another foot this way, and it just felt really weird, really uncomfortable. One bullpen, we moved to the middle [of the rubber] and everything felt a lot smoother. I was able to get to the outside corner and the inside corner without forcing anything, without opening early.”

So Schwellenbach brought the new starting position into his next appearance. In 11 starts since, he’s allowed an ERA of 3.00 and an opponent line of .213/.255/.366, with just 12 walks and two hit batters in 66 innings.

In that time, Schwellenbach has tripled the use of his two hard arm-side pitches, the splitter and sinker. And he’s managed to keep opponents off his four-seamer more. When he was throwing from the third-base side of the rubber, opponents tagged the heater for a wOBA of .435. Since his June 30 start, that’s down to .249.

As with Strider, there’s an extent to which Schwellenbach was raw for a college prospect — especially one who’d had success at a fairly big program — and is still developing well into his major league career. But he’s been very impressive even in his limited major league experience. Among NL rookie pitchers, Schwellenbach is fourth in WAR behind Paul Skenes, Shota Imanaga, and Yoshinobu Yamamoto.

Suffice it to say, this is not a normal rookie class. If it were, Schwellenbach would be getting at least lukewarm Rookie of the Year consideration; he’s about to pass 100 innings pitched with a 3.12 FIP and K/BB ratio of 5.5. Against all odds, he’s almost made up for the absence of that other Spencer. Which raises an obvious, if terrifying question.

What kind of unholy flamethrower will the next generation of Atlanta Spencer turn out to be?