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, who 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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Robbie Ray - San Francisco Giants (Curve, Sinker)
Robbie Ray has looked pretty good in four starts since coming off the IL in his recovery from last year’s Tommy John surgery. In 20.1 innings, he’s posted a 3.98 ERA, 1.18 WHIP, and 22.6% K-BB%. That has also come with a 31% CSW and 17% swinging strike rate (SwStr%), which are all things we like to see.
His four-seam fastball is actually up in velocity from 2022, averaging 94.2 mph compared to 93.4 mph, but the biggest change that I’ll highlight today has been the return of Ray’s curveball.
When we last saw Ray in 2022, he had slowly phased out a curveball that he used 12% of the time in 2021 and had also introduced a sinker over that summer. In 2024, it seems that the curveball has come back in a big way and the sinker is gone. But are those positive changes?
For starters, Ray is using his curveball 7.4% of the time to lefties and 20.2% to righties, so it feels much more like a weapon for right-handed hitters. That makes sense since, so far, it has registered a 29.7% SwStr% against righties with a 34.4% CSW and just a 37.5% Ideal Contact Rate (ICR) allowed. All of that is pretty good, as is his 42.2% chase rate, which has led the curve to be a strike on 61% of pitches. All-in-all, that seems like a pretty solid weapon for him.
However, we should also note that this is not the same curveball he was using so often in 2020 and 2021. Back in 2020, when he threw the curve 12% of the time, it averaged 83 mph with just 1.4 inches of horizontal movement and five inches of drop and had a spin rate of 2,321 rpm. Now the pitch is about 84 mph with less overall movement, both vertically and horizontally, and less spin. Since he uses a knucklecurve grip, that’s exactly what you want. Since knuckle curves have less spin and more velocity than a traditional curve, pitchers can release knuckle curves from a height and angle that’s closer to their other pitches, which adds more deception.
A Baseball Prospectus article from 2014 mentions that “There is a significant tendency toward ground balls and away from pop-ups among knuckle curve throwers, which perhaps explains the higher BABIP. (Robbie Ray does have a high BABIP on his curve). However, there may also be a tendency to swing and miss more frequently... These trends are consistent with poorer pitch recognition by the batter (on average) when a knuckle curveball is thrown.”
All of which is to say, the curve addition feels nice for Ray and the added velocity on it could help it pair better with his slider.
The other change Ray made this year is to scrap his sinker. The pitch was added in 2022 to give him some variation on his four-seam fastball. Both fastballs had roughly the same velocity and spin, but they broke in different directions which was meant to create deception and also allow Ray to attack different parts of the zone.
"[Hitters] were taking the slider below the zone. They weren’t really chasing it,” Ray said in an interview with MLB.com in 2022. “In the zone, it seemed like they hit it every time. So for me, I was just thinking if I get something to go that way instead of everything coming kind of inside to them, because they kind of seemed like they were just looking in. Like everything coming in, in, in. And so I just thought if I could get something going the other way, it might change the look. It might knock them off guard.”
The idea makes sense, but it wasn’t as great in practice. Since Ray is left-handed, the sinker was not a pitch that was overly successful against righties. He used it 21.6% of the time in 2022, but it allowed a 41% ICR and a .314 batting average. It did post an 11.3% SwStr%, which is good for a sinker, but you’re usually not adding a sinker to get swings and misses. The contact he allowed was relatively hard, and the pitch was more effective to lefties, but his four-seamer was already good against lefties, so did he need another version?
In 2024, Ray has started to throw his four-seamer inside more to lefties, perhaps to compensate for the loss of the sinker, and the four-seamer and slider combination against left-handed batters has been enough for him in the past. There’s a strong argument that’s all he needs for those hitters, which means replacing the sinker with the curve to righties gives him more swing-and-miss and reduces some hard contact.
Now, most of his pitches still do come inside to righties, which could allow them not to look to protect the outside corner, as Ray mentioned in the quote above, but he has started using the four-seam fastball out there enough that it might be all he needs to keep hitters from cheating.
VERDICT: MEANINGFULLY IMPACTFUL. The sinker wasn’t a great pitch for Ray, and he won a Cy Young in 2021 by using a similar pitch mix, so we can’t be too mad about him going back to it. I think the strikeouts will still be there and the park will help mitigate some of his home run issues, so I’m all in on this version of Robbie Ray.
Zach Eflin - Baltimore Orioles (Change-up, Fastball usage)
When pitchers are traded, we almost always see some immediate changes as they adapt to a new organization. It’s rarely not throwing a new pitch (because it takes time to learn those), but it can often be in the location of pitches or how often a pitcher uses a given pitch. For Zach Eflin, the Orioles have already shifted how often he throws his changeup and how he utilizes his fastball variations against lefties and righties.
Below is a quick look, using Alex Chamberlain’s Pitch Leaderboard, of the first-half and second-half changes for Eflin. I wanted to use it to present a small visual example, but we’ll break down the exact pre- and post-trade changes and their impact below.
Despite not registering on the image above, the biggest change has been with Eflin’s changeup. Before the trade, Eflin threw his changeup just 3.3% of the time, but that has gone up to 11% in the three starts since then. On the surface, that makes sense since the changeup grades out well in Pitcher List’s PLV metric. He has used it almost exclusively to lefties but is throwing it all over the strike zone. It has a nearly 50% zone rate and has been used inside, outside, up, down, middle, etc.
It seems like Baltimore is just banking on the speed variation of the 85.1 mph changeup from the 92.2 mph sinker he’s been using more against lefties as well. Since both have some arm-side run, there could be some added deception in using both of them to pound the strike zone. So far, Eflin has just a 6.7% SwStr% with the changeup in Baltimore but a minuscule 16.7% ICR and a strong 58.3% groundball rate. That’s good.
Another modification appears to be how often the Orioles want Eflin to throw his cutter versus righties. He threw the pitch to righties 15.6% of the time prior to the trade but is up to a whopping 35.8% since the trade. That’s a massive change. So why would the Orioles want that?
For starters, FanGraphs Stuff+ has the cutter as his second best fastball behind his sinker, which has consistently been his most-used righty pitch. He also threw it up in the zone just 12.3% of the time to righties, keeping it low, 52.2% of the time. The Orioles have dialed back on that significantly, having Eflin pound the strike zone with the pitch, throwing it middle 50% of the time. It’s also outside 50% of the time, so it’s not a middle-middle pitch, but he’s no longer just using it low in the strike zone.
In the three starts in Baltimore, the cutter missed significantly more bats with a 16.7% SwStr% and a solid 83.3% strike rate compared to an 8% SwStr% and 68% strike rate in Tampa Bay. In that sense, attacking righties with it over the plate has made sense, but it has also been getting hit hard, with a 55.6% ICR to righties, compared to 48.6% before the trade. Yet, so far, the pitch has just a .222 BABIP which has led to a .118 batting average that doesn’t feel entirely sustainable.
Another change in fastball usage has been Eflin’s deployment of his sinker and four-seamer. Before the trade, he threw the sinker 39% of the time to righties and the four-seam fastball 9.4% of the time. To lefties, that split was 22% sinker and 10.2% four-seam. The Orioles have dialed back his sinker usage to 32% against righties and essentially cut out the four-seam fastball entirely with a 2% usage to righties. To lefties, Eflin has kept a 10% usage on the four-seam and upped his sinker usage to nearly 27% to lefties.
The sinker usage difference to lefties is minimal, but the sinker has been super effective against lefties in the three starts with Baltimore, posting a 25% ICR, with a 70% strike rate. Eflin has also been throwing the pitch inside to lefties nearly 48% of the time, up slightly from 43% in Tampa, which is likely causing a lot of jam shots as it starts off the plate inside and hits the inside corner. That’s a solid strategy that would then set up the changeup away or the four-seamer up and away, which is where he primarily throws them to lefties since coming to Baltimore. That also brings us full circle to why Baltimore is upping his changeup usage. When paired with the increased sinker usage to lefties, it all starts to work together.
VERDICT: MINIMALLY IMPACTFUL. What we like most about these changes is that Eflin is deepening his arsenal again. Since he doesn’t have overwhelming stuff, adding more pitches allows him to mix and match during starts and keep hitters guessing, which is what guys like Chris Bassitt and Merrill Kelly have done with some success for a few years now. Adding in the changeup or throwing more sinkers to lefties doesn’t make Eflin an ace, but it likely makes him a pitcher who will give up less hard contact, as does him throwing his four-seam less. The floor is raised a bit here, and when you add the team context and the great home park, those are real changes to his value.
Trevor Rogers - Baltimore Orioles (Fastball Usage, Changeup versus righties)
We just talked about Eflin, so we should probably talk about his new teammate Trevor Rogers, who has also seen his fastball usage change since coming to the Orioles. With the Marlins this season, Rogers threw his four-seam 33% of the time overall and 35% to righties, while throwing his sinker 23.4% of the time overall and 22% to righties. The Orioles have shifted that, having Rogers throw his fastball just 24.4% overall and 29% to righties while throwing his sinker 28% of the time and 28.3% to righties.
On the surface, I understand the move. The four-seam is Rogers’ worst pitch according to Stuff+ with a grade of 69 and is also his worst pitch by PLV with a grade of 4.98. The sinker isn’t much better, but swapping out your worst pitch for a slightly better pitch makes some sense. However, PLV, which factors in location, says that the pitches are incredibly similar when he throws them to right-handed hitters with the four-seam grading out at 4.89 and the sinker coming in at 4.92.
The results before the trade also suggest that the four-seam fastball might not actually be a worse option for Rogers, despite what Stuff+ thinks.
Against righties, the four-seamer had a 40.5% ICR in Miami with a 65.7% strike rate and 12.7% SwStr%. Meanwhile, the sinker had a 48% ICR against righties with a 64% strike rate. Since coming to Baltimore, both pitches have been hit incredibly hard with the four-seamer registering a 55.6% ICR against righties, and the sinker posting a 71.4% mark. However, the four-seamer also misses more bats, so if both pitches are being hit hard, and the sinker has been hit harder for most of the season, maybe it’s better to go with the pitch that’s at least getting some swings and misses.
Additionally, much like Baltimore has had Eflin lean into distinct pitch mixes for both left-handed and right-handed hitters, it seems that they are doing the same for Rogers by modifying the use of his secondary pitches. In Miami, Rogers threw the slider 20.7% of the time overall and 18.3% to righties. Baltimore has kept the overall slider usage the same but limited his usage against righties to just 11.1%. Similarly, in Miami, Rogers thew his changeup 23.1% of the time overall and 24.8% to righties, while that usage has increased to 27.1% overall and 31.1% to righties in three starts with the Orioles.
Both of these changes make sense on the surface as well. The changeup is Rogers’ best pitch by PLV and Stuff+ and has been a great offering so far this year against both righties and lefties. He gets swings-and-misses to hitters of both-handedness and doesn’t allow a lot of hard contact to either, so him leaning into that pitch more is something we like to see.
While Rogers’ slider does weirdly have a higher SwStr% against righties than lefties, it also gets hit hard with a 49% ICR. If he’s also using his sinker more against righties then he has three pitches he can still throw with a four-seam, sinker, and changeup. The issue, of course, is that only the changeup really misses bats to righties, and we kind of hate relying on starters in fantasy baseball who only have a changeup as a strikeout pitch.
VERDICT: NOT IMPACTFUL. The bottom line is both of Rogers’ fastballs are bad, and his slider is not a true pitchout pitch. I understand what Baltimore is doing with their subtle pitch mix changes, but it hasn’t yet yielded better results, and I’m not entirely sure it will. Until Rogers can recapture the 15.1% SwStr% slider from 2021 I don’t think he’s useful in fantasy formats.
Zebby Matthews - Minnesota Twins (Whole arsenal)
Zebby Matthews made his debut on Tuesday, and I felt it was worth digging into because he’s such an interesting starting pitching prospect. The 24-year-old right-hander began the year in High-A and was dominant in four starts, so he was promoted to Double-A, where he posted a 1.95 ERA, and 0.76 WHIP with a 63:6 K:BB ratio in 10 games (nine starts). In 97 innings on the season, he’s posted a 2.60 ERA, 2.12 FIP, and 2.51 xFIP, while striking out 30.5% of hitters, and walking just 1.9%, which is the lowest walk rate among Minor League full-season qualifiers. Matthews has thrown strikes 70% of the time this season, which would rank him first in MLB, right ahead of Tarik Skubal (69.9%), and George Kirby (69%).
So what does Matthews bring to the table and how did he look on Tuesday?
Matthews’ fastball velocity has continued to increase this season. Despite throwing 92 mph on average when he entered the professional ranks, Matthews has hit 99 mph this season with a 90th-percentile fastball velocity of 96.6 mph. In his debut on Tuesday, he sat 95.1 mph with only slightly above-average extension, which was a little disappointing given his tall frame. His fastball is relatively flat and he generally commands it well up in the zone, but he wasn’t as precise in his debut, which is understandable given the nerves. He did consistently throw the pitch for strikes, but he just didn’t get it up in the zone as much as we’d like to see and the pitch had only one whiff on the day but a solid 31.6% CSW.
While none of his secondary offerings is truly elite, he commands all of them well with above-average Location+ grades in the minors, which allows each pitch to play up. Before this season started the Twins eliminated the sweeper that Matthews used to throw and then split his cutter into two distinct pitches, a higher-vert cutter used mostly against left-handed hitters, and a gyro slider.
The slider graded out as his best pitch on Tuesday. He threw 16 of them, mixing them in to both righties and lefties, which may change in the future since he failed to get a single whiff to lefties and allowed his only hit on the slider to a lefty. Granted, it’s a small sample size, but Matthews threw his slider low in the zone 69% of the time and glove side 50% of the time, which means it would be down-and-in to lefties, which is the sweet spot for left-handed hitters. To combat that, Matthews seemed to throw the pitch more over the heart of the plate to lefties on Tuesday, which is not ideal.
While the cutter didn’t grade out as well on Tuesday, it did register a 22% SwStr% and got swings and misses against both righties and lefties. Matthews demonstrated elite command of the pitch, which we’re seeing is a trend, and peppered the inside third of the plate to lefties. He did allow a home run to MJ Melendez on one of them, but it looked like a good pitch when watching it live, and I wasn’t sure the ball was going to get out. I think you just tip your cap there as a pitcher.
The changeup and curveball were less utilized in his debut and seem like pitches meant to just round out the arsenal, but he has good command of both of those as well, which gives him five pitches he can mix and match on any given day. When you combine his elite command, deep pitch mix, and increasing velocity, it’s hard not to like what Matthews brings to the table. It reminds me a little bit of the profile Spencer Schwellenbach has and that has worked out pretty well so far this season.