In addition to the exciting new bat metrics introduced at Baseball Savant last season, arm angle data for pitchers made their debut. This can provide insight into pitchers who have tweaked their arm angle from 2024 to 2025.
There can be a variety of reasons why a pitcher would want to adjust his arm slot. For some, it varies a bit depending on the pitch they are throwing. A season-to-season change indicates a more mechanical shift to possibly improve command, velocity, pitch movement, or all of the above.
Roughly a week into the season, let’s take a look at some pitchers who have dropped their arm slot. For most pitchers here, they’ve only thrown one or two starts so things are fluid. I’ve included roughly 60 pitchers who have dropped by at least three degrees below and will identify a few interesting names.
Meyer made one of the more drastic arm angle changes from last season to this season, dropping from 46.1° in 2024 to 37.7° in 2025. In conjunction with the arm slot tweak, he’s increased the velocity of all his pitches, leading to an improvement in his Stuff+. With his four-seam, he increased the iVB (15.1 → 15.7) despite dropping his arm angle. It still isn’t the best pitch as it gave up a lot of hard contact in his first start (1.171 xSLG), but the physical characteristics look improved.
Meyer has split time between the minors and majors for the past three seasons. He got off to a strong start last season with a 2.12 ERA in 17 innings before inexplicably being sent back down. Then, he returned in the 2nd half and wasn’t nearly as effective.
Meyer’s arsenal is centered around his bullet slider, which he throws roughly 40% of the time. Beyond that, he’s morphed into a more kitchen sink approach with his four-seam, sinker, sweeper, and changeup all thrown more than 10% in his first start. We’ll see what kind of distribution he lands on for the rest of the season, but it’s not a bad idea.
A potential impact pitch for Meyer is his sinker. Thrown only 1.9% last season, he whipped it out as a righty exclusive pitch, throwing it 32.6% in his first start. The early returns were excellent with a tiny 0.133 xwOBACON, although on only 3 batted balls. Possessing multiple fastballs is becoming more and more popular across baseball, and we saw a few cases last season of how important it can be. See Hunter Brown’s splits after implementing a sinker last season, for example.
Max Meyer, Nasty 91mph Slider. 😨 pic.twitter.com/npwViMzLHB
— Rob Friedman (@PitchingNinja) March 30, 2025
Players who have experienced some struggle in the majors and made tangible adjustments are the ones to pay attention to. It’s far too early to know the story with Meyer, but it looks positive for now.
Luzardo came out firing in his Phillies debut with 11 Ks in 5 IP along with a strong 18.9% SwStr% against the Nationals. His arm angle was 39.3° last season and lowered to 33.3° so far in 2025. Similar to Meyer, he boosted his velocity on most pitches and saw an overall improvement in his Stuff+ as he is feeling froggy returning from injury.
In addition to his arm slot change, Luzardo is now throwing a sweeper to lefties. His more side-arm arm slot is more conducive to throwing a heavy horizontal pitch like a sweeper. His sweeper averages 86.9 MPH which so far ranks as the 7th hardest in baseball.
Further, his changeup now has more arm-side run (15.9 → 17.0) and is more than 2 MPH harder, which helped it grade out better and perform well. Luzardo has had some trouble against opposite-handed hitters in the past (2.76 xFIP vs. LHH, 4.16 xFIP vs. RHH), so his upgraded changeup could help.
Along the same lines, his revamped slider is up from 83.5 MPH to 86.8 MPH. The magic number for slider velocity is at least 85 MPH, so being above that number is another positive. He’s toned down the usage on the pitch, throwing it mostly backfoot to righties. It tore Nationals hitters up, generating an 83.3% Whiff%.
Jesús Luzardo’s 7th and 8th Ks…thru 4. ✝️🦎 pic.twitter.com/JJnV92n1ij
— Rob Friedman (@PitchingNinja) March 29, 2025
It is cool to see the Phillies mold Luzardo in the way they’d like. With these changes, Luzardo could be in for a nice bounce-back season.
Leiter has looked electric in his first two starts of 2025 a 10/1 K/BB ratio in 10 IP. Nate Schwartz had an awesome breakdown of what makes him the epitome of modern pitching. Leiter dropped his arm angle from 50.3° to 45.1° which has perhaps helped his control and command. He had already been a Stuff+ darling, but these tweaks along with other factors have helped take it even further.
The big offseason development for Leiter was adding a sinker and tweaking his changeup to a kick-change. Eno Sarris dug into the birth of the kick-change and what differentiates it from a splitter or changeup.
Leiter compromised less than an inch of vertical ride on his four-seam with the arm slot drop, which is a fair trade-off. He was mostly a four-seam and slider guy last year throwing them roughly 80% of the time. Hitters seemingly keyed in on these two pitches as they both ran negative Run Values. Leiter has thrown five pitches more than 10% of the time this season helping keep hitters guessing.
The biggest area of improvement is his ability to throw his electric stuff in the zone. So far, his Zone% is up from 49.8% to 53.9%, which would be among one of the better marks among starters last season. For what it’s worth, while Location+ takes longer to stabilize, so it’s not totally accurate yet, his Location+ is up from a poor 96 to 108 this year. I wouldn’t expect that to stick, but we can check back here in a few weeks to see where he is at.
Jack Leiter, 99mph Paint. 🖌️🎨 pic.twitter.com/YA6BpPnujO
— Rob Friedman (@PitchingNinja) April 2, 2025
Arrighetti was already among some of the lower arm angle pitchers last season and has dropped even more this season. He dropped it from 24.6° to 20.5°, which puts him right next to Aaron Nola’s borderline side arm slot.
Arrighetti had a top 20 K rate (27.1%) last season among starters as a rookie (min. 120 innings). At the time, his Stuff+ lagged a bit at a below-average 95. However, since the incorporation of the arm angle data in the updated Stuff+, it looks more in line with his K rate.
Arrighetti’s fastball now rates as a top 12 pitch among starters this year despite its average velocity. The shape is similar to Twins’ starter Joe Ryan, who does a great job of elevating it. Arrighetti’s performed poorly last season primarily because he left it in the heart of the zone too often. If he can keep its location mostly up in the zone, he should find better results.
A unique pitch in Arrighetti’s arsenal is his curveball. Utilized last season as his best put-away pitch, it has as much glove-side movement as many sweepers (-17 HB). In fact, it has more horizontal break than his sweeper. It’s an invaluable offering that he can use to both hands.
Spencer Arrighetti, Filthy 82mph Sweeper (home plate view). 😷 pic.twitter.com/qUvF1FlYZE
— Rob Friedman (@PitchingNinja) March 29, 2025
Similar to many pitchers, Arrighetti is adding a sinker to be a bigger part of his repertoire this season. He threw only 10 all last season and while he only threw 2 sinkers in his first start, it should be something he continues to mix in as an option on the inside part of the plate to righties as the season goes along and as he gets more comfortable with it.
Smith-Shawver has generated some buzz in the early going of the season. He also appears here as a guy who dropped his arm angle from 50.7° to 47°. Breaking into the big leagues as a 20-year-old in 2023, Smith-Shawver has not quite found his footing yet. Between the Braves having a good and deep rotation and his struggles, he was up and down between the minors and majors.
Tabbed with 60 future grades on his fastball and changeup, those are the pitches Smith-Shawver relies on the most. The classifications varied a tad on his changeup, but it is now being called a splitter.
This season, his pitch usage is interesting as he is throwing his splitter most frequently (35.1%). He doesn’t really throw it in the zone and relies heavily on generating a chase outside the zone, which he did to great effect in his first start against the Padres at 47.6% and a whopping 71.4% Whiff%. The right-hander made a remarkable improvement to his splitter movement profile. He maintained a similar level of vertical drop and velocity but increased the average arm-side movement by nearly 9 inches (9.6 HB → 18 HB). It is truly a disgusting pitch. In total, however, he struggled with his command quite a bit, with three walks in only 4 IP.
Disgusting stuff from AJ Smith-Shawver.
22 Inches of Horizontal Break. pic.twitter.com/nvGhYdFao6
— Rob Friedman (@PitchingNinja) March 31, 2025
That pitch distribution differs a lot from last season, when he threw his fastball more than half the time. Furthermore, he is experimenting with a new slider that could be a valuable pitch he uses for strikes. It isn’t the wide arsenals of some of the other pitchers on here, but it is good to see adjustments from a young player, and we’ll see how it helps him moving forward.
