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.
We’re going to mix it up this week (haha) by looking at the overall pitch mixes of four rookie starters who debuted this week in the hopes of seeing what we can expect long-term.
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Shota Imanaga - Chicago Cubs (Four-Seam)
Shota Imanaga shot out of the gates this season, looking like one of the best pitchers in baseball until the middle of May. Even though we knew that some regression was bound to happen, it was also true that Imanaga had the best Stuff+ numbers in the World Baseball Classic and had better strikeout numbers than Yoshinobu Yamamoto in Japan, so there was reason to be optimistic about the left-hander’s success transitioning to the MLB level.
A big part of that early success was, perhaps surprisingly, because of his fastball. Even though Imanaga’s fastball averages 91.7 mph on the season, it’s an elite pitch because of its shape and location. On the season, Imanaga’s four-seam has 17.8 inches of Induced Vertical Break (iVB) and a Height Adjusted Vertical Approach Angle of 1.4, both of which are over the 90th percentile. That means that Imanaga has a flat fastball that excels in the top part of the strike zone. That’s also why he throws his fastball up in the zone 57% of the time, which is well above average.
Pitcher List’s PLV grade for Imanaga’s fastball is 5.63, which is the 100th percentile. Since PLV takes into account pitch shape but also location (whereas Stuff+ separates location into another metric) I like to use it as a barometer for the overall success or upside of a pitch. Imanaga’s fastball has an 11% swinging strike rate (SwStr%) on the season and a 70% strike rate which are strong numbers for a four-seam. He doesn’t really make mistakes on it with just a 1.2% mistake rate, and even though he does give up a lot of fly balls, it hasn’t come back to bite him too much.
Until recently.
In his last start against the Mets, the wind was blowing out at Wrigley Field and Imanaga gave up a few long balls; however, there may have also been another factor at play. Imanaga’s four-seam was down to 16.9 inches of iVB with a Height Adjusted Vertical Approach Angle of 1.3. It was also down to just 90.1 mph. The location was still good, but with diminished velocity and a slightly steeper approach to the plate, the pitch is more hittable both because of the slower speed and because the steeper angle means that it more closely matches a hitter’s upward bat path. As a result, hitters won’t swing under his high fastball as much, and solid contact on a high fastball usually leads to damage.
The issue is that this isn’t a one-time thing. In his start on June 15th against the Cardinals, Imanaga had an iVB of 16.1 inches and a Height Adjusted Vertical Approach Angle of 1.2. His fastball was 91.1 mph that day, which was below his season-long mark but not by much. That start overall was fine, but he got just two whiffs on his fastball that entire game and had a 17.6% CSW on the pitch. In his start before that against the White Sox, his iVB on the fastball was at 17.4 with a Height Adjusted Vertical Approach Angle of 1.4, which is not too far off from his season-long marks, but he got just three whiffs on his fastball in that start.
Could this just be a poor stretch? Of course, but it’s at least something we need to keep an eye on. Imanaga’s four-seam has been a major part of his success this season and a foundational component of his arsenal. He needs the fastball to work to get ahead of hitters and set up his splitter and sweeper. He uses his four-seam early in the count 63% of the time and has a 71st percentile first-strike percentage with it. If those early fastballs start turning into hard-hit base hits then he’ll need to adjust his entire approach to get out major league hitters. He has a strong enough arsenal to remain fantasy-relevant if he has to do that, but it won’t be at nearly the same level we saw in the early months of the season.
VERDICT: MEANINGFULLY IMPACTFUL. Just not in a good way. Again, it’s entirely possible that this is a blip in just a small two-start stretch, but it is worth watching to see if he can get the velocity and/or shape back on his four-seam fastball in the coming games.
Tobias Myers - Milwaukee Brewers (Four-seam, Changeup)
There aren’t many pitchers who are on the type of heater that Tobias Myers is on. Over his last four starts, he has a 0.71 ERA, 0.75 WHIP, and .189 wOBA allowed in 25 1/3 innings. Granted, that has come with just a 19.8% strikeout rate, but it’s hard to ignore that kind of success. So what, if anything, has changed?
One of the first things you notice is the increased reliance on the four-seam fastball from 37% usage in April to 48% during his June hot stretch. That should be interesting considering he throws just 92.4 mph and, on the season, has just an 8% SwStr% on his four-seam. How is throwing that more often helping him?
Well, for starters, Myers does have excellent shape on his four-seam fastball. He has above-average extension at 6.7 feet and has elite iVB with 18.6 inches. That leads to a flatter-than-average fastball with a 1.1 Heigh Adjusted Vertical Approach Angle. Since he also has a 73% strike rate with the pitch and doesn’t give up a lot of hard contact with just a 36% Ideal Contact Rate, it grades out well in Pitcher List’s PLV metric with a score of 5.33 where 4.94 is league average.
If you want to see how it stacks up against other pitchers, we can look at Pitcher List’s Fantastic Four score which combines the four key components for a four-seam fastball (velocity, extension, iVB, and Height Adjusted VAA). On Sunday, Myers had a Fantastic Four score of 107. That was sixth best of every starter on Sunday, behind guys like Paul Skenes, Bryce Miller, and Pablo Lopez but ahead of Max Scherzer, Framber Valdez, Nestor Cortes, and Michael King. In his start on June 18th, his Fantastic Four score was 110, which was third-best on the day, ahead of Cortes, King, Luis Severino, Aaron Nola, Pablo Lopez, and Nick Lodolo.
All of which is to say, Myers has a solid fastball despite the middling velocity and his leaning on it more makes sense. However, despite his fastball being relatively flat, he’s actually not throwing it up in the zone often. He has just a 40.4% hiLoc% (high location) on the four-seam in June and a 30% y-mLoc%, which means throwing it middle as opposed to up or down. When compared to his season-long numbers, it means he’s throwing far more fastballs middle and less up in the zone in June.
So how is that working for him?
One part could be luck, but the other part could be him working in his changeup more as well. He’s now throwing the changeup 12% in June and has yet to allow a hit on the pitch in the month. In fact, over the last month, only one changeup has been put in play and it resulted in an out. Now, the changeup itself is likely not the cause of this. It grades out poorly with a 4.27 PLV where 5.01 is average, and Myers doesn’t command it well with a 17.5% zone rate even during this good stretch.
In my opinion, the benefit is more about the changeup working better with his other pitches than the curveball did. Myers’ primary offerings, aside from his four-seam, are a cutter that has 13 inches of vertical movement and a slider that’s an 85.4 mph tight slider with just 1.3 inches of drop. Both are pitches that he keeps in the zone relatively often and are also pitches that don’t have the “hump” that his curveball does when leaving his hand.
If you look at the Savant graphic below, you can see that the four-seam, cutter, slider, and change all approach the plate from a similar trajectory before the slider and cutter move away from righties and the change-up darts down and in.
To me, the modification for Myers has been more about leaning on the four-seam and then following that with a pitch mix that creates deception off the fastball. If he’s not going to miss bats with his stuff, he can at least try to keep hitters off the barrel by pounding the strike zone with a collection of pitches that all appear similar out of the hand. So far, it’s working.
VERDICT: MARGINALLY IMPACTFUL. It’s obviously impactful because he’s had a great month of June, but I’m not sure this is a change that makes Myers a player you’ll roster all season long. He’s making the most out of an arsenal that has one above-average pitch. That could continue to work against average and below-average offenses, but I think Myers is going to settle in as a streamer and potentially not even a high-priority one.
Kyle Gibson - St. Louis Cardinals (Curveball)
Kyle Gibson is another pitcher riding a bit of a hot streak, posting a 2.55 ERA, 1.01 WHIP, and 19.6% K-BB% over his last four starts. That K-BB% is also propped up by a 27.8% strikeout rate which is up a huge amount from his 21.3% season-long mark and 18.8% career mark. So what has he changed over that timeframe that has led to more swing and miss?
Well, the only significantly notable change in the pitch mix is an increased usage of the curve. It should be noted that Gibson’s strikeout rate was already up this season because he upped his sweeper usage in 2024 to 22%. The pitch has a 22.8% SwStr% on the year with a 27.7% PutAway rate, which measures how often a two-strike pitch turns into a strikeout. That’s an 87th percentile rate. He keeps the sweeper low in the zone 82% of the time and gloveside 70.5%, which is the type of command that has helped it get a 5.68 PLV grade. The pitch does get hit hard when contact is made, with a 48% ICR, but it has made him a more dynamic starter.
That’s also the case with the curve.
Gibson’s curveball is a bit slower this season and with more vertical movement than last year, which has helped it miss more bats. It has an identical 22.8% SwStr% but is more successful early in the count with just a 19.2% PutAway rate that is essentially league average. Gibson keeps the pitch low 78% of the time but uses it all over the strike zone, middle, in, and away, etc. The pitch grades out well with a 5.49 PLV that’s 91st percentile and Gibson will throw it to both righties and lefties, even though he uses it more to left-handed hitters. However, much like the sweeper, it gives up a lot of hard contact with a tremendously high 60% ICR.
Yet, it has been impactful for Gibson. He got 10 whiffs on the curve alone in his June 8th start against the Rockies, got another two whiffs on it with a 70% CSW against the Astros on June 3rd, and got four whiffs and a 72.7% CSW on May 28th against the Reds. The pitch has a 36.4% SwStr% and 81.8% strike rate over his last four starts.
Now, it will likely never be a high-usage pitch because he has trouble throwing it in the strike zone with just a 38.6% zone rate. That makes it heavily reliant on swinging strikes and is part of the reason he will dial back on it in some games, like on June 14th against the Cubs when he only threw it once. Yet, it does give him another high-swinging strike rate pitch to go to when he faces a lefty-heavy lineup or doesn’t want to use the sweeper as much. It’s not a coincidence that he used the curveball 24.7% of the time against the Rockies which was a game in which he threw his sweeper just 15% of the time, his lowest rate since the first start of the season.
Still, even as a complementary pitch, it’s an important one for him in a season where he is relying more heavily on his sweeper and will need to compensate against lefties.
VERDICT: MINIMALLY IMPACTFUL. The major impact on Gibson’s increased strikeout rate has been his reliance on the sweeper, which has been his most used pitch over this stretch of games. However, the increased usage of the curve provides Gibson with another swing-and-miss offering so that he doesn’t need to rely on the sweeper against lefties. Since his cutter, four-seam, sinker combination can be mixed and matched to limit hard contact, Gibson’s two breaking balls now give him a little bit more of a strikeout floor. That’s useful for a pitcher who has shown the ability to keep his ratios in check for long stretches over a season. I’m not sure he’s more than a priority streamer when he’s running well, but he’s running well right now.
Michael Lorenzen - Texas Rangers (Slider, Cutter)
Although he’s certainly not on the level of Blake Snell and Jordan Montgomery, we waited for a while to see where Lorenzen would land this offseason, and then an opportunity with Texas opened up, and the right-hander found himself in the rotation. He’s pitched well too with a 3.04 ERA, 1.16 WHIP, and 37.6% ICR. He’s only had one start all season where he allowed more than three runs and just one other start where he allowed exactly three. For the most part, you assume Lorenzen is going to give you a quality start whenever he goes out there, so is there anything he’s doing differently this year that’s leading to that?
Well, for starters, Lorenzen has worked a cutter into his arsenal far more this season, throwing it 11% of the time on the year after only throwing 22 total cutters in 2023. He’s also seemingly abandoned his harder slider and replaced it full-time with a sweeper. In the graphic from Alex Chamberlain’s Pitch Leaderboard below, you can see how he’s made those changes throughout the season too.
We’ll start with the cutter since it has become a bigger piece of Lorenzen’s arsenal over the last five starts. Despite its name, the pitch has very little horizontal movement and a little bit of dive. He has added a touch of cut this season and is doing a tremendous job of using it inside on lefties with an 88th percentile inside location rate against them. Overall, the cutter has a 14.2% SwStr% and a 29% ICR, which means he misses lots of bats and doesn’t get hit hard. The reason Pitcher List’s PLV metric doesn’t love it is that he has just a 45% zone rate with the pitch and misses inside with it a lot. Still, missing inside doesn’t often lead to damage, so I have no problem with him throwing it there because the outcome has seemingly been: a swinging strike, weak contact, or a ball. I’ll take that.
The increased usage of the cutter meant Lorenzen’s slider was less necessary. The slider graded out slightly above average but it was 86 mph with little horizontal movement and about three inches of drop. In many ways, similar to the cutter. Considering it didn’t miss bats with just a 10.1% SwStr%, it makes sense for Lorenzen to go with the cutter more often. However, the introduction of the sweeper has been less successful.
On the season, the pitch grades out as exactly league average. It has a 4.4% SwStr% and 54.5% ICR, so it doesn’t miss bats and it gets hit hard. Lorenzen has only thrown three sweepers all season to lefties and he does a fine job of keeping it low against righties, with a 63% low location that’s slightly above average. Yet, he doesn’t keep it away enough, with 76th percentile middle location and 9.2% of his sweepers have been middle-middle, which is well above league average, so the command of the pitch has not been great.
In June, that’s gotten slightly better with just 7.1% of his sweepers being middle-middle and 68% of them being located low. However, he’s still not getting them on the outside part of the plate enough to righties, so he has just a 7.1% SwStr% on the pitch over his five June starts and a 66.7% ICR. That’s not going to make any meaningful impact on his success even though I like the idea of a sweeper to add to the cutter.
VERDICT: MARGINALLY IMPACTFUL. The turn to the cutter over the slider is a nice change for Lorenzen and one that I think will help his ratios; however, right-handed batters are having way more success against him this year, and he really lacks any pitch that can consistently get swings and misses against righties except for a decent four-seam fastball that also gets hit hard. This is a tough tightrope for him to walk, and I think we’ll see a few right-handed heavy lineups start to get to him a bit in the coming starts.