Opening Day has arrived, there’s a new season underway, and it’s a wonderful time to be a baseball fan. So what better thing to do in this time of new beginnings than dwell on the past just a little bit? Though we’d love it if you thought the opposite, sportswriters are not infallible beacons of knowledge who evaluate every player correctly on the first try every time. No more beating around the bush, I was WRONG about Spencer Schwellenbach.
Maybe that’s a bit harsh: my issues with him were valid enough at the time, based on what he had shown and the data available then. Let’s be a bit more gracious; I underestimated Schwellenbach. When I wrote about him last season, he was inexperienced even by the standards of a rookie pitcher, and was scuffling through his first month in the majors. He had shown some promise and flashes of potential but had noticeable problems that I assumed would take him some time to work out. Well, dear reader, he had mostly solved them within days of the article going up. To better understand how he did it, let’s break down my old thoughts on Schwellenbach and how his performance in the following months addressed the concerns I had.
A Brief Re-Evaluation Of His Arsenal
In my defense, the first mistake I made when I initially looked at Schwellenbach was due to something I could not have known at the time. When I tore apart his fastball, saying it only had velocity and approach angle going for it, I was missing a third positive trait. The movement direction of his four-seam is a ways off from his arm angle. This is true of most 4-seamers, but due to the way Schwellenbach was cutting his four-seam, it’s a larger gap than normal. Now this isn’t the biggest change ever, and I do still think his fastball looks better than it is, but that being said, it’s perhaps not as much of a hindrance to his success as I had previously believed.
I was right that his slider is an excellent pitch, with the depth, power, and control to overmatch hitters. However, I think I slightly misjudged the way in which it would be effective. His usage of the pitch, and his ability to land it at the bottom and directly below the zone so consistently, turned it into a way for Schwellenbach to manage contact and get strikes on command. While he does throw it looking for strikeouts, and it gets them at an above-average rate, this is a do-it-all pitch for him.
I don’t want to waste time rehashing absolutely everything I said in that article, but those two pitches stood out to me. Doing the rest of the arsenal a bit more quickly, his splitter is still excellent and is the equalizer he needed against left-handed hitters. I’ve concluded that his curveball works because he commands it well, it’s deceptive, and he has a knack for mixing it in when hitters aren’t expecting it. I still have mixed feelings about his cutter, which is good when he can fool hitters into losing the coin flip of guessing whether it’s in the zone. He gets those called strikes and chases, but it gets crushed when they guess right and it’s in the zone. Lastly, he used his sinker oddly down the stretch in 2024, equally against lefties and righties as a rare offering from deep in his pocket. In his first start of 2025, he threw it exclusively to righties, which would play to its strengths, and used it far more than normal. It’s a good pitch and I’d love to see it worked in a bit more to take some pressure off of everything else.
A Broader Look
Stepping back a bit from individual analysis of each pitch he throws, the next part was about the bigger problems he faced. He always had enough stuff to succeed, even when I underrated it. The two main things I noted were that he was struggling badly against opposite-handed hitters, and that he was getting obliterated the third time through the order.
I suggested he throw fewer four-seamers and cutters to lefties and try working in the slider to them a bit more, thinking he could find more success that way. I’m not egotistical enough to suggest that he did the following to spite me, but he proceeded to do the opposite of what I had said and started throwing more four-seamers to lefties than he had previously. He then varied his strategy a bit, eventually settling on a full kitchen sink approach. He was mixing in four-seamers, splitters, curves, and even those sliders I had asked for while dialing back the cutters (hey I got one right!).
As for pitching the third time through the order… Bear with me, this is the dumbest table I’ve ever had to make, and it’s because I missed something very important the first time I looked at this.
Look at that first column. That’s an awfully specific stat. HR/FB% the third (or more) time through the order. Wouldn’t you know it, small sample sizes can skew the data. I don’t know what I was thinking trying to judge results on a 30-batters-faced sample, I must have just not noticed. Completely missed that he gave up three homers on just seven flyballs in that span. Even if they were well-earned homers, that’s unsustainable. Skewed isn’t a strong enough word, it obliterated any chance of him not looking like he had a problem until you saw how small the sample was.
Unsurprisingly, that evened out and his numbers the third time through the order looked normal (if a bit lucky on the homers, ironically enough). Even by the end of it though, those early homers still ruined the ERA for the sample. Yeah, that tangent from the first article was completely pointless. I had honestly forgotten that that was one of my critiques, I discovered this while writing this one. That mistake did not inspire this article but the moment I noticed it, it was too stupid to not include.
Anyway, the point was to look back at what I had said previously, and how I underestimated Schwellenbach’s ability to adapt quickly to major league hitters. Let’s get back to that.
Final Thoughts On Final Thoughts
Moving past that embarrassing blunder, I closed with how I believed he was going to be a very good pitcher, despite the flaws I had been pointing out. The purpose was never to pick the guy apart, but rather to take note of the things he needed to work on so we could track his progress.
I mentioned his relative inexperience when compared to his peers. He barely pitched during his college baseball career due to being a two-way player. I figured this was a double-edged sword: his arm had less mileage, but it might take him a bit longer than other rookies to really come into his own. Excluding the data misstep from earlier, that was probably my biggest misjudgment. Maybe his quick ascent through the minor league ranks should have been a sign, or maybe it could have been attributed to him riding a wide, high-quality arsenal. Looking back now it’s clear it was something else.
Schwellenbach is either very intelligent, very well coached, or (probably the most likely), both. His quick adjustments on the fly to his mix and command during his rookie season helped him rise to become one of the league’s most trustworthy pitchers before even accruing his first year of service time. Due to his style of throwing a variety of pitches and his aggression in the zone, I still don’t think he’ll ever lead the league in strikeouts, but that’s never disqualified a pitcher from ace status.
