Even though many pitchers will test new pitches in the spring, they can often be abandoned when the regular season starts. It can often be more informative to see which pitchers have drastically changed their pitch mix or pitch shape after a few starts in the regular season. It’s not as common, and the changes aren’t as drastic, but it allows us to see how a pitcher is reacting to what he’s seeing from hitters and gives us a glimpse into what the pitcher thinks he needs to do to be successful.
With that in mind, we will continue with the premise of the series I had called Pitchers with New Pitches (and Should We Care) by breaking down notable changes in a pitcher’s pitch mix (hence “Mixing” it up). We’ll look at pitchers throwing a new pitch, have eliminated a pitch, changed their pitch mix meaningfully, or are showcasing a different shape/velocity on a pitch. It will mostly be positive changes, but sometimes we’ll point to a change we’re not excited about but could have a meaningful impact on a pitcher’s fantasy outlook.
I’ll continue my analysis with the simple premise that not every new pitch should be greeted with praise. A new pitch, like a shiny new toy, might be exciting on its own, but it also needs to complement what a pitcher already has and fill a meaningful void in his current pitch mix. We want to check and see if he has any splits issues. We want to see what his best pitch(es) is and see if this new pitch would complement that. Then we want to see what this new pitch type is generally used for (control, called strikes, etc.) and see if that is something this pitcher needs help with. We can also now see the pitch in action to look at the shape and command and see if it’s actually any good. Once we’ve done all that, we can decide if the pitch is a good addition or not.
If you missed any of the previous editions of this series, you can click this link here to be taken to the tracker, which I’ll update as the season goes on. It also includes links to the original articles so you can read them in full if you’d like.
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Shane Baz - Tampa Bay Rays (Whole arsenal)
We’ve been talking for weeks about stashing Shane Baz and how he could be a second-half difference-maker. He finally made his eagerly-awaited season debut on Friday, so I wanted to look at what we’re seeing from him after he missed an entire year recovering from Tommy John surgery.
On the surface, there are a few things we love. He was throwing in the upper 90s on his fastball, even if he fell to 93-94 mph late into his start. That’s cool. The Rays allowed him to go six innings and over 90 pitches. That’s pretty cool. He also flashed a three-pitch mix, which gives him a solid foundation for success. So let’s see just how excited we should be.
As you can see from the chart above, Baz relied heavily on his four-seam and slider in his first start, mixing in some curves and just four changeups. Only the slider and fastball were able to earn whiffs and his 21% whiff rate and 27% CSW on the day are fine but not great.
Let’s start with that fastball. It came with above-average velocity at 96.2 mph, slightly above-average extension at 6.6 feet, and a solid 16.3 Induced Vertical Break (iVB). It’s a relatively flat fastball that he kept up in the zone 54% of the time, which should help it get whiffs. It didn’t get a ton of whiffs on Friday, but when you look at all the components of the pitch, it’s a pretty good fastball. Pitcher List has a cool Pro Tool that ranks a pitcher’s fastball on a given night based on four key factors (velocity, extension, iVB, and height-adjusted vertical approach angle). On Friday, Baz had the second-best fastball, behind Tyler Glasnow but ahead of Paul Skenes. Not a bad place to be, so I expect this fastball to produce more in future starts.
The other crucial pitch for Baz is his slider, which is a bullet slider at 87 mph with just three inches of sweep. The pitch is slightly slower and flatter than when we last saw it in 2022, losing some vertical drop and adding a bit more horizontal movement. We’re dealing with just one game here, but the pitch missed more bats in 2022 and graded out better on Pitcher List’s PLV metric back then as well; however Baz did a good job of keeping it low last week, and it still looks like it could be an above-average offering for him. We’d just like to see it be a touch more dynamic like it was two years ago.
Baz then rounds out his arsenal with a curve that he seems to have tweaked by adding almost two mph. The added spin gives it a little bit more movement and the new shape led to a better PLV grade than the pitch we saw in 2022. He also had a 50% zone rate on the pitch and a 60% strike rate, so it seems like he can command it well, which is nice to see. He technically also has a changeup, even though he only threw four of them in his first start, all to lefties. He threw just one in the zone for a called strike and the other three basically bounced, but, hey, at least he kept them low.
VERDICT: The fastball gives Baz a solid foundation to work off of, and while his slider may have taken a slight step backward, his curveball appears to have gotten slightly better. His overall strikeout ceiling may be capped if that slider doesn’t miss bats like it did in 2022, but it’s nice to see Baz back with good velocity, a long leash, and a solid three-pitch mix. I’m not sure the upside is sky high this season, and I think there will be some rough starts along the way, but it’s nice to see Baz back and throwing in MLB games, and it wouldn’t be a shock to see him improve as the year goes on.
Spencer Schwellenbach - Atlanta Braves (Sinker, Splitter)
When we first saw Spencer Schwellenbach, he was a 24-year-old straight up from Double-A, who technically threw five pitches but relied a lot on a four-seam fastball that was just a slightly above-average pitch that didn’t miss bats. In the span of just a month and a half, we’ve seen him not only tweak his pitch mix but also add another pitch, change his grips on previous pitches, and change where he stands on the mound. It’s a lot of change to unpack
What should stand out from the image above are two things: one is that Schwellenbach has done a good job of spreading out his pitch mix, dialing back the usage of his four-seamer and throwing his whole arsenal more regularly. The other is that he added a sinker to that pitch mix.
The sinker has been an interesting addition for Schwellenbach of late. The pitch itself doesn’t miss many bats and he is still fine-tuning the command of the pitch, but he does a really good job of keeping it arm-side, throwing it mainly inside to righties, which helps keep them off the plate. Perhaps the biggest benefit of the pitch is that it gives hitters another fastball to have to worry about and, for right-handed hitters, it gives them a fastball that they have to worry about jamming them inside. Of late, that has kept hitters off of his four-seamer and also allowed him to rely on the four-seamer less, which has been good because he has had some issues with the inconsistency of the shape of his four-seamer, so it’s probably best not to have to rely on it 30+% of the time.
The addition of the sinker also facilitated another change where the Braves moved him from the third-base side of the rubber to the first-base side of the rubber to give the sinker more space to move back over the plate. This has also allowed him to occasionally throw backdoor sinkers to righties or sinkers that start at a left-handed hitter’s hip, which has been useful. It’s been a good pitch for him, helping his ratios and helping induce more weak contact.
Schwellenbach has also started to add in a splitter more often after not even using it in his debut. In truth, much of Schwellenbach’s arsenal is new since he was a closer in college and missed his first professional season after having surgery. The curveball was a pitch he added last season in the minors, but the splitter and cutter are both pitches he really worked on this offseason. That means it may take time for him to be fully comfortable with them. Perhaps we’re seeing that increased comfort now with the splitter. He threw 16 splitters last time out against the Phillies, getting five whiffs and posting a 43.8% CSW on the pitch.
He uses the splitter almost exclusively to lefties, but it grades out as an above-average pitch by PLV, getting a 5.26 grade where 5.06 is league average. He throws it in the zone about average for a splitter, but it has a ridiculous 28.6% swinging strike rate (SwStr%) to lefties. Over 51% of his splitters are thrown in two-strike counts, and he has an 83rd percentile putaway rate on the pitch so it has tremendous success as an out pitch. Perhaps it’s because he will also throw a cutter, sinker, and four-seamer to lefties that it’s tough to pick up on the splitter out of his hand. The addition of the pitch has given him a plus swing-and-miss pitch to lefties to go along with good SwStr% and PutAway rates on the cutter and four-seamer to righties.
VERDICT: MEANINGFULLY IMPACTFUL. Schwellenbach is just 24 years old but has shown tremendous ability to adjust and change on the fly. That feels like a good indicator of his potential future success. Right now, he has four above-average pitches in his slider, cutter, curveball, and splitter, and the new sinker has lessened the impact of his inconsistent fastball, which was his biggest weakness. I don’t know how long the Braves will give him in the rotation given their desire to win a World Series and his limited experience and previous pitch counts, but I’m growing bullish on Schwellenbach’s long-term role in this rotation.
Gavin Williams - Cleveland Guardians (Slider/Cutter)
It’s hard to know what to make of Gavin Williams right now. The 24-year-old made his season debut last week after battling elbow injuries and turned heads by seemingly scrapping his slider from last season and turning it into a cutter. Last year, the pitch averaged 84.9 mph with less than one inch of vertical break and 3.7 inches of sweep. In his debut last week, the pitch was 91.6 mph with seven inches of vertical break and no sweep. Then he came out on Monday night and threw the pitch at 88.3 mph with slightly more vertical and horizontal movement.
At this point, without talking to him, it’s hard to know if this is related to the elbow injury, a grip change, or Williams just getting behind the ball more and throwing it harder. What we do know is that the slider was a good pitch for him last year, posting a 16.3% SwStr% and allowing just a 32.2% Ideal Contact Rate (ICR), so it would not have been my first choice of pitch to change. However, he was also throwing his slider harder as the year went on last year, averaging about 83 mph over the summer but finishing the season averaging almost 87 mph in September. So perhaps what we’re seeing through these first two starts is just a continuation of that.
The pitch did post a solid 33% whiff rate on Monday night with a 61% strike rate, so perhaps this upper 80s version of it could perform better than the 91 mph version in the debut. Only time will tell, but I think we’re seeing something closer to the harder version of the slider we saw last year but perhaps his feel for it needs to improve. I wouldn’t be panicking yet about his slider being removed from his arsenal.
It was also nice to see Williams’ fastball perform so well on Monday. He averaged 97.5 mph with it while also showcasing elite extension at 7.1 feet. The iVB isn’t great, but it’s a relatively flat fastball due to his release point, and he did an amazing job of keeping it up in the zone 68% of the time on Monday. According to Pitcher List’s Fantastic Four leaderboard, it was the best four-seamer of any starting pitcher on Monday (even though it was a small sample size). He also showcased a tremendous curve on Monday with the pitch getting five whiffs and posting a 34.6% CSW and 77% strike rate. So even with the questionable changes to the slider/cutter, Williams flashed two plus offerings on Monday, and we’ll have to hope it’s not just because he faced the Tigers.
VERDICT: MINIMALLY IMPACTFUL. Right now, it’s too early to tell what kind of changes Williams is making to his cutter/slider. It might wind up just being the pitch he was throwing at the end of last year. However, we can be optimistic about the success of the four-seam and curveball based on his first two starts. The health concerns remain, but I’m buying in here if given the chance.
Jameson Taillon - Chicago Cubs (Sweeper, Curve, and Cutter)
Jameson Taillon was somebody I was in on coming into the season based on the changes we saw in the second half last year. So far, that has carried over into a solid season and Taillon, going into his start on Tuesday night, had a 3.19 ERA over 29 starts, which was 172.0 innings. That’s far better than the league average, which means we’ve seen Taillon before a good starting pitcher for long enough that his success shouldn’t be a surprise. Still, the veteran continues to evolve, and we’ve seen a shift in his approach over this season as well.
Since the start of the season, we’ve seen a few key changes for Taillon. He has dialed back the usage of his four-seam fastball in favor of bringing in his sinker more often. He’s also started to use his slider more. We’ll discuss those changes below, but it’s also important to keep in mind that Taillon has mentioned tinkering with his arsenal before and has talked openly about approaching each start differently based on the opponent and which pitches feel good during a given start. That means we may simply be looking at a stretch where his slider feels good or where he doesn’t feel as good about his four-seam.
Taillon has been using his sinker primarily against right-handed pitchers, throwing just four all season to lefties. It doesn’t miss bats, with just a 4.7% SwStr%, and he also doesn’t have a great zone rate on the pitch, but I should note that his command of the pitch has been improving lately with a 70% strike rate or better in three of his last four starts. The pitch also induces just a 23.5% Ideal Contact Rate (ICR), which is elite and really the main purpose of Taillon’s usage of it, I would assume.
He uses the pitch early in the count and does a good job getting it inside on the hands, with an 84.4% inside location rate to righties, which is the 99th percentile. Using the sinker more often has also enabled Taillon to use the four-seamer more in two-strike counts since the pitch has a better-than-average PutAway rate to righties despite a below-average SwStr%. By using the four-seamer more sparingly and not having to count on it to get called strikes early in the count, Taillon can ensure that hitters don’t time the pitch up as well. That also makes it more successful in two-strike counts because hitters haven’t already seen it multiple times in an at-bat or might even think it’s the sinker out of the hand and then swing under the four-seam.
That change has been one of the reasons Taillon’s strikeout rate has ticked up, but I think another is his increased reliance on the sweeper. It’s just been about four starts with the sweeper being involved more, so it’s unclear how permanent that change is, but the pitch does have a 20.2% SwStr% which is TAILLON’S ONLY PITCH IN DOUBLE DIGITS. Yes, every single other pitch that Taillon throws has a sub-10% swinging strike rate. When you look at it from that perspective, the sweeper is super important to his fantasy upside because strikeouts are important to fantasy upside.
It also doesn’t hurt that the pitch has a 34.6% ICR, which means it’s not being hit overly hard, and that Taillon has a 70% strike rate with it, which means that he can command it well. He does a good job of keeping it low in the zone but doesn’t always bury it outside to righties. He’s happy to throw it low but over the middle of the plate, and he’ll even mix some in against lefties; although, not a lot.
Lately, it seems like the sweeper is taking a lot of the space left by the curveball, but Taillon prefers to throw the curve to lefties, so it could also just be the lineups he’s faced recently. However, the increased usage of the sweeper and the flattening out of his arsenal means that Taillon has six pitches he’s comfortable mixing and matching on a given day. That raises his floor a bit because he can come up with specialized attack plans for each opponent, and the sweeper has also raised his fantasy ceiling, so it’s all good news here. We also know that Taillon is on the trade block with the Cubs struggling, so perhaps a move to a team like Baltimore or Cleveland could even improve his value more.
VERDICT: MEANINGFULLY IMPACTFUL. It’s meaningfully impactful FOR NOW. We know that Taillon will tinker, so it’s unclear how long this usage pattern will last, but he’s been a useful fantasy pitcher for over a season now and if he continues to miss bats the way he has been recently, you’re going to be really happy he’s on your team.