It's Wednesday, which means it's time for us to visit the bump on Hump Day and discuss starting pitcher news. Each week in this article, I'll be taking a deeper look at a few trending/surging starting pitchers to see what, if anything, is changing and whether or not we should be investing in this hot stretch.
The article will be similar to the series I ran for a few years called Mixing It Up (previously Pitchers With New Pitches and Should We Care?), where I broke down new pitches to see if there were truly meaningful additions that changed a pitcher's outlook. Only now, I won't just look at new pitches, I can also cover velocity bumps, new usage patterns, or new roles. However, the premise will remain the same: trying to see if the recent results are connected to any meaningful changes that make them worth buying into or if they're just mirages.
Each week, I'll try to cover change for at least four starters and give my clear take on whether I would add them, trade for them, or invest fully in their success. Hopefully you'll find it useful, so let's get started.
Most of the charts you see below are courtesy of Kyle Bland over at Pitcher List. He created a great spring training app (which he's now carried over into the regular season) that tracks changes in velocity, usage, and pitch movement. It also has a great strike zone plot feature, which allows you to see how the whole arsenal plays together.
Chandler Sampson, Caleb Durbin and Luke Keaschall join the rankings.
Chris Sale - Atlanta Braves (Arm Slot Change, Four-Seam Fastball Location)
Last year was a resurgent season for Chris Sale, who pitched more innings than he had in any season since 2017 and won the NL Cy Young Award with a sparkling 2.38 ERA, 1.01 WHIP, and 32% strikeout rate. While nobody expected him to duplicate that feat this year, the first five starts of the season from the 36-year-old have been far more troublesome than anybody could have imagined.
Though five starts, Sale has allowed 17 runs (16 earned) on 31 hits in 23.1 innings while striking out 32 and walking seven. The strikeout rate is solid, and his overall velocity remains the same, but a 6.17 ERA and 1.63 WHIP are alarmingly high for the veteran. So what could be the root of the problem? Thanks to Alex Chamberlain's Pitch Leaderboard, I spotted something that could explain a bit of these issues.
As you can see from the chart above, Sale has dropped his arm angle by four degrees. The scale above uses zero degrees to signify a pitcher who releases from a pure side-arm angle, perfectly parallel to the ground. The fact that Sale has fallen from 11 degrees to seven degrees is a pretty stark difference when you're already that close to side-arm. It could be just a comfort issue for Sale, who might feel better pitching from a lower arm slot; however, pitchers can sometimes lower their arm slot to compensate for fatigue or pain in their normal delivery. We have no evidence that this is the case for Sale, but given his injury history, it's hard to prevent the thought from popping into your head.
The more immediate issue is what the lower arm slot has done to the movement profile on Sale's pitches. Through five starts, Sale has the lowest grades he's ever gotten on pitch models. His slider has lost almost an inch of horizontal movement and 2.5 inches of drop, while his four-seamer has lost a little bit of Induced Vertical Break (iVB). However, the bigger issue has been his fastball locations.
Sale has a relatively flat fastball with a 1.2 Height Adjusted Vertical Approach Angle. That means, the vertical approach angle, after controlling for the release point of the pitch, fights the drop of gravity more than the average fastball. Those types of fastballs work better at the top of the strike zone since they appear to "rise" rather than drop as they approach the plate. Last season, Sale threw his four-seam fastball up in the zone 59% of the time overall and 62% of the time to righties. This season, he has thrown it up in the zone just 51% of the time overall and 53% of the time to righties. While that may not seem like a major issue, failing to get the fastball up in the zone has led to him also throwing 9.3% of his fastballs middle-middle, which is worse than the league average and up for Sale from last year.
It wouldn't be a stretch to think that lowering his arm angle has made it harder for Sale to elevate his fastball as much as he did last year. He's fastballs have landed middle far too often this year, and that has led to a staggering 72.7% Ideal Contact Rate (ICR), which is a Pitcher List stat that measures barrels and solid contact and hard groundballs allowed. That means 73% of Sale's four-seam fastballs have ended in ideal contact for a hitter, which is why the pitch has allowed a .536 average, 13.6% barrel rate, and .630 wOBA. The pitch also has just a 14% PutAway Rate this season, down from 22% last season, which means he's missing far fewer bats in two-strike counts.
Since the cause of the arm angle change is unclear, it's hard to see how permanent it is. All we know is that Sale seems healthy from a velocity standpoint but is struggling from a pitch shape standpoint, and his fastball has taken the brunt of that. If he can fix the locations on the four-seam fastball, we could look at this as a small five-game blip, but there are some reasons to be mildly concerned right now.
Landen Roupp - San Francisco Giants (New Cutter, Different Change-up)
Roup jumped onto my radar last year when Eno Sarris was gushing about him after a few late-season starts with the Giants. Up until that point, I had not been aware that Roupp was posting 39% strikeout rates in the minors or a 35% strikeout rate in a full minor league season in 2022. I knew that he had battled some injuries and was sometimes used in the bullpen, but when the Giants announced they were going to let Roupp try to earn a starting rotation spot, I was intrigued. Then I became even more intrigued when he showed up to spring training with a few changes to his arsenal.
The most obvious change for Roupp has been the introduction of a cutter. He's only thrown the pitch 6.4% of the time overall this season, but he uses it 14% of the time against lefties and throws it 83% of the time early in counts as his primary fastball to them. He does a good job of locating the pitch up and in and pounds the zone with it at a 56% zone rate and 72% strike rate to lefties.
He does use the sinker to lefties as well, and he locates that up in the zone often, so the two fastball variations play well off of one another, but using the cutter up and in also sets up his changeup, which he throws 19.4% of the time to lefties and keeps down in the zone 96% of the time. He has also added more movement overall on the changeup, so he's been able to post a solid 37.5% chase rate on the pitch to lefties this year.
You can also see in the graphic below how well his changeup (green dots) tunnels with his sinker (orange dots) with similar release points and attack angles, but with a six mph velocity gap and different movement profiles.
The tunneling effect of the changeup and sinker is also part of the reason Roupp has upped his changeup usage against righties to 10%, and the pitch has posted a 19% SwStr% to them so far.
You can also see that Roupp has a very East-West movement profile with the sinker and changeup running arm-side, and then his big curveball (blue) featuring tons of gloveside movement. Since Roupp has a lower release point, his curve has a lot of sweep, with about 20 inches of horizontal movement and 10 inches of vertical drop that make it almost like an old school slurve. He uses the pitch confidently to both righties and lefties, and while it misses more bats to righties, it's an above-average swinging strike rate to both, and he does an impressive job of keeping it low in the zone.
All of this means that Roupp now has three pitches that he can throw to hitters of both handedness, including a fastball that he can command for strikes to both, and a true go-to pitch in his curve. He's had all this success so far this season while sporting a .358 BABIP, and while there may be some ups and downs in his first full season in an MLB rotation, I expect Roupp to be somebody you want to hold on your roster all season.
Walker Buehler - Boston Red Sox (Four-Seam Shape, Sweeper Usage, Changeup shape)
It has not been a great start to his Red Sox career for Buehler, who has a 4.23 ERA, 1.19 WHIP, and just a 22.6% strikeout rate in his first five starts. However, there has been some mild cause for optimism that goes beyond, "He faced the White Sox in his last start."
When I ranked Buehler as SP51 in my pre-season starting pitcher rankings, part of my reasoning was that "Boston hates to throw four-seam fastballs, which is great because that pitch has become a mediocre one for Buehler. The Red Sox could easily lean into his cutter and sinker more as early fastballs and then dial up his sweeper usage, and we could be looking at another strong season for Buehler."
In his last two starts, we started to see that attack plan come into focus a little, but in particular in his last start against the White Sox.
As you can see from Kyle Bland's Live Pitching Stats above, Buehler has not backed off the four-seam fastball. He used it 30% of the time against the White Sox and 27% of the time overall on the season, just a slight decrease from last year. He is throwing it early in the count slightly less than last year, but the two changes that stand out are that he's throwing the pitch inside to righties way more, and the vertical movement seems to be coming back.
Last year, Buehler threw the four-seam inside to righties 14% of the time. That has jumped to 39% this year. Jamming hitters inside could be a big reason why the batting average and ICR allowed to righties have fallen considerably. He has also added both vertical and horizontal movement to his four-seam fastball, which has tweaked the vertical approach angle enough to make this pitch succeed up in the zone more than it did last year.
However, the fastball inside to righties has also freed up the outside part of the plate for Buehler's sweeper, which was been a big usage change for him this year. As you can see above, he used the sweeper 15% of the time against the White Sox and has used it 14% of the time on the season, which is up from just 4% last year. The pitch also has 2.5 more inches of horizontal movement and now comes in with over 18 inches of horizontal break and very little vertical break. It has graded out as his best pitch so far and has a staggering 28.3% SwStr% to righties. It also has a 70% strike rate on the year, and has been a real difference-maker for him.
One of the last changes I wanted to highlight was with Buehler's changeup. He's nearly doubled his usage of the pitch to lefties in 2025 and has produced far better swinging strike rates and ICR marks despite showing less command of the pitch. Part of the reason the command has gotten worse is that the movement profile on the pitch has changed drastically, with less drop by over three inches more arm-side run. He's also using the pitch far more in two-strike counts, and it has gotten plenty of swings and misses out of the zone and has a well-above-average PutAway Rate.
Yes, his fastball velocity has been down a bit, and the new tweaks to his pitch shapes have led to inconsistent command early on, but it's beginning to get easier to see the Red Sox's plan for Buehler right now. He has a primary four-pitch mix to righties with both his four-seam fastball and a sinker that he can throw inside. He then uses the cutter and sweeper away from swinging strikes. Against lefties, he'll use all three fastball variations and then use both the curveball and changeup to try and miss bats. That's a deep pitch mix with varied shapes and attack locations, and can certainly lead to a run of success as he starts getting more comfortable with it.
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Andrew Abbott - Cincinnati Reds (New Cutter, Arm Slot Change, New Changeup Shape)
I will admit to never being a huge believer in Andrew Abbott from a fantasy standpoint, but his 3.69 career ERA in 258.1 MLB innings has maybe proven that he's a solid big league starter. However, his 16 strikeouts in 11 innings in his first two starts gave me reason to dig in and see if anything had changed this year that was worth me modifying how I think about Andrew Abbott.
The first change was that he appeared to add a cutter this off-season. As a lefty whose four-seam fastball had a below-average swinging strike rate and league-average ICR against right-handers last year, that makes some sense. However, so far, he's only thrown five of them, and the vast majority have been down and in to righties. I'm not sure that's what he wants to do, and the pitch doesn't seem to have lots of break in on the hands, so we've seen a new pitch, but I'm not sure it's anything that actually moves the needle. Abbott also has a new cutter, which he’s thrown 5 times, all in the first or second pitch of an at-bat to righties. Usage is still pretty low (~5%). He’s also hammering down-and-away from righties, as opposed to elevating away like he did last season (see below).
However, one of the things that may move the needle is a new movement profile on his changeup. As you can see from Kyle Bland's pitch chart below, the changeup has over three inches more vertical drop and slightly more arm-side run. He's also almost doubled the usage of the pitch against righties up to 32% this year from 19.4% last year. His SwStr% has jumped to 23.3% on it from 12.5% last year, and that would be huge for him since he doesn't want to rely much on his sweeper to righties, and both his four-seam and curve didn't miss many bats against righties last season.
Abbott can now use the four-seam, curve, and change to righties and eventually mix in the cutter more often, while going four-seam, curve, sweeper to lefties.
The other change I saw this season was that Abbott has added almost two inches of vertical break to his four-seam fastball while getting rid of some of the arm-side run. I think a lot of that has to do with the fact that his arm angle seems to be raised almost four degrees. That has changed the shape of the pitch and gotten him a little more swing-and-miss, but the fastball velocity is also down to 91.2 mph after being 92.8 mph last year. I don't love that. I also don't love that he's using the fastball low in the zone far more often than he did last year.
At the end of the day, I like the idea of the cutter, and I love the new movement profile on the changeup, but I'm not sure I like the new four-seam fastball if the arm angle is the cause of the velocity dip. When you add that to the fact that he pitches in one of the best parks in baseball for offense, I still think Abbott is more of a streaming option for me until I can see a larger sample size with this new approach and arm slot.
Eduardo Rodriguez - Arizona Diamondbacks (Cutter Shape, Slider Shape, Changeup Command)
Early on in the season, it's easy to get caught up in trying to find the "new breakout star" or the pitcher who has changed their arsenal the most and could be in for a breakout. I understand why. I do it too, so I don't knock it. However, there can also be some value in looking for a veteran pitcher who is making subtle changes to potentially unlock the best version of themselves. The current SIERA leaderboard is littered with names like that: Chris Bassitt, Logan Webb, Nathan Eovaldi, and Eduardo Rodriguez.
Rodriguez has always intrigued me because he seems to have a season every other year where he flashes an intriguing skill set. In 2018, with Boston, we saw that 3.82 ERA and improved command. In 2021, we saw the strikeout rate jump up to 27%. In 2023, we saw a (luck-fueled) 3.30 ERA. That whole time, Rodriguez has been a solid but unspectacular pitcher who seems to vacillate between being better than his poor results and not being quite as good as his strong results.
Well, through four starts in 2025, Rodriguez is top-15 in SIERA, K-BB%, strikeout rate, and xFIP. It's a small sample size, but it made me think it might be worth digging into to see if anything is different.
For starters, I noticed that, like Andrew Abbott, Rodriguez has raised his arm angle a bit, which has led to more vertical movement across his arsenal but less horizontal movement. The vertical attack angle on the arsenal overall is up, and some of the pitch models like it, with Pitcher List giving Rodriguez the highest PLV grade he's had since 2021.
The biggest change I see is with his cutter. It now has 1.5 inches more vertical movement, which means it's dropping less than it did last year as it approached the plate. He's throwing it up 10% more and inside to righties 6% more to take advantage of that added "rise". It also seems like keeping it up in the zone is helping his swing-and-miss because he's elevating it out of the strike zone with two strikes, and his two-strike chase rate has jumped from 9% to 20% this year. Additionally, the PutAway Rate on the cutter is 40% to righties, which means it has been really effective as a strikeout pitch for him. Overall, the cutter has posted a SwStr% of 14% and an ICR of 37.5% after posting just a 6% and 56.3% mark respectively last year. Those are intriguing changes, but may just be small sample size noise.
However, we have also seen some minor changes in his slider as well. The pitch is about 1 mph harder with 1.5 inches more vertical drop and 1.5 inches more horizontal break this season. It's another pitch he's using in the zone far less often than he did last year. This year, his slider has a 34% zone after posting a 51% zone last year. While that may not seem good, he's throwing the pitch exclusively to lefties and using it low in the zone 89% of the time, up from 65% last year, which means he's starting it near the bottom of the zone and letting it drop out of the strike zone. It may not end up in the strike zone, but the SwStr% on the slider jumped from 3.5% to 13.6% this year, so the new approach change on it has really helped his strikeouts.
Part of the reason he can do this is because the command of his changeup has improved, so he can throw the four-seam, sinker, and changeup for strikes and then use the cutter and slider for whiffs out of the zone. The zone rate on change is up 6%, but the strike rate is up 16% on the year. The movement profile and locations are similar, he's just missing in the left-handed batter's box far less and throwing more competitive changeups.
All of these are minor tweaks, and the four-seamer is still getting hit a lot, but the added swing and miss feels real if Rodriguez can keep his command gains. I'd be trying to add him and see how long this new approach lasts for because he'll be useful in all league types while it's here.
Matthew Pouliot
