Five young pitchers with the stuff (and command!) to break out this season
The research tells us that command is a little more finicky year to year, but stuff stays sticky. So we often chase the young pitchers that have the nastiest pitches — that makes sense. But to be a successful starting pitcher, there’s no way to ignore the fact that command is very important.
Here’s another way of demonstrating the fact. Let’s look at previous breakouts in the past four seasons, since we’ve had tools like Stuff+ (to appraise the physical properties of a pitch independent of results) and Location+ (to assess pitch type and count-adjusted command). There are 55 pitcher seasons in which a starter under 25 had good results (a SIERA under four) and threw 50 innings, and 60 in which that same pool produced poor results (over a 4.5 SIERA). Here’s how they compared by stuff and command.
So the good players had better stuff and better command. News at 9. Let’s look at the most-thrown pitches in baseball and see how they differentiated themselves on the pitch level.
There’s a slightly bigger difference between the good and bad groups when it comes to fastball stuff, but the good group also had better sliders. Seems a good fastball and slider are important in today’s league!
When we compare the breakout group to the struggle group by command, though, something seems to pop.
This statistic, Location+, does not have a large spread, so while these differences look muted, there’s a real trend here. The breakout pitchers had much better command of their fastballs and sliders than the strugglers did. Here’s an interesting tidbit: Of the 55 breakout pitcher seasons, only five had below-average locations on their primary fastball. Only one (Aaron Ashby) was below average on all his fastballs as well as his slider.
It seems that having command of one of your harder pitches is a barrier to entry for the young starter. That’s a little bit of an old truism that shows in the advanced data.
So now we can look at young pitchers last season (25 or younger) who started at least three times, showed above-average locations on at least one of their fastballs and had above-average stuff. Here’s the whole lot of them.
This is basically a list of the most exciting young starters in baseball, so it feels good right off the bat. Bobby Miller seems perfect in almost every way, but he also performed admirably in his first attempt at the league. Some of these guys have already broken out. Let’s try to get ahead of the curve and pick some sleepers who likely have better days ahead of them. Listed with the player are their ERA from the past season and their stuff-based projections (Pitching+ projected ERA, or ppERA) for next season.
2023: 4.82 ERA
2024: 3.78 ppERA
Here’s the list of pitchers that have thrown 200 innings over the past two seasons and struck out at least thirty percent of the batters they faced: Spencer Strider, Shohei Ohtani, Blake Snell, Greene, Brandon Woodruff and Carlos Rodón. That’s a good list to be on. The reason he’s got an ERA almost two runs higher than the rest of the group is that he’s given up 1.6 homers per nine innings, almost double the rest of the group’s rate.
Where do homers come from? Poor stuff, poor location, park factors and being predictable, most likely. Greene sits 98 with decent movement for that velocity, and throws an 87 mph slider — stuff is not the problem. His command grades from scouts coming back were above average, and his locations at the plate have been above average. The hitter has only been ahead in the count for 13 of the 43 homers he’s allowed, so it’s not necessarily falling behind in counts either.
There’s some evidence that smaller arsenals struggle more the third time through the order, Greene throws 95 percent fastballs and sliders, and Greene has allowed 25 of 43 homers in the fourth inning or later — these things seem related. It would be great to hear about another pitch in spring, perhaps a curveball that he can throw for strikes when batters are anticipating one of the other two pitches. Even so, Stuff+ has been shown to affect home run projections in the past, and home run rates have more noise in them than most pitching stats, so there are a lot of different ways that Greene could take a step forward. There’s a great foundation here.
2023: 4.32 ERA
2024: 3.84 ppERA
Miller started hot last season, but an up-and-down finish left him with just bad enough of an ERA to consider what he does in 2024 a breakout. Call it cheating, since he had three months with sub-four ERAs last season and showed off a great fastball, but there are still some boxes to check for the Mariners righty.
The fastball is a big check mark, as he has great ride on the pitch and averages 95 mph. The harder breaking ball got great results (batters hit .202 off of it) and it’s a model-pleaser as well, at 87 mph. The sweeper checks out in the model, but batters only swung at it around a quarter of the time, perhaps because these are his release points on his primary pitches.
Since the scale on this image is so large, the difference between the sweeper release and the fastball release is around five inches vertically and also horizontally. Batters must be able to spot it somehow. Miller adapted to some extent.
“It works as a freeze-take pitch,” he confirmed late last season, “but I’ve got a few other tricks up my sleeve.”
Progression of the splitter continues 🧪 pic.twitter.com/crYPFdVAyK
— B Money (@Bryce_miller9) December 22, 2023
A split-finger could help Miller leap forward, especially because it could help him against lefties, who slugged 240 points higher against him than righties last year. But at least he’s starting with good stuff and command of at least one of his harder pitches.
2023: 5.59 ERA
2024: 3.93 ppERA
By the Pitching+ model, Bradley probably has everything he needs. Among pitchers who threw at least 100 innings last season, only Spencer Strider had a better fastball by Stuff+. Bradley’s curve (96 Stuff+) and changeup (131 Stuff+) look like the foundation of a fuller arsenal, and he showed the ability to locate his fastball and cutter at an average rate, at least. So what happened with his disastrous finish to the 2023 season?
The cutter is the crux of the matter. When Bradley was sent down, he was told by the team to focus on throwing the cutter faster, he got that velocity up, and then he was called up. But even at the harder velocities, the Stuff+ model didn’t like the pitch much (88 Stuff+ for the year) and the results weren’t there either (.581 slugging for the year, .767 slugging on cutters over 90 mph). The caveat: He only threw 41 cutters over 90 to lefties and had better results (.300 slugging). Maybe this result is still worth chasing:
But against righties, it looks like he should use his curve and splitter more often. The good news is that they are theoretically good pitches, and he also got good results on both last year. Bradley has only been pitching regularly since high school and he’s 22 years old right now. He struck out 28 percent of the batters he saw last year, walked them at an average rate and has the pitches he needs to succeed. Maybe he just needs to mix them up a little differently.
2023: 5.09 ERA
2024: 3.87 ppERA
The story on Brown is that he has great stuff and can’t locate the ball. So, for his first full season, he went out there … and his stuff receded while he threw to above-average locations once you adjust for count and pitch type. Strange.
His slider lost velocity. His curveball lost horizontal movement and got harder. His four-seam lost velocity. His mechanics fell off.
“I think some things in my mechanics changed — probably due to fatigue — without even realizing it,” Brown said, in a piece from Chandler Rome detailing his efforts to get back.
“I was getting a little bit more crossfire, which diminished my ability to get the fastball away to right-handed hitters especially and leaving it more arm-side. Righties, in particular, were able to do more damage on my harder fastball (and) cutter because I wasn’t getting it extension side due to those mechanics. Those were some (things) we talked about and I have to stay on it this year and keep making adjustments as the season goes on.”
From April to June, when Brown had an ERA under four, he was throwing his fastball and cutter away to righties about a quarter of the time more often than he did later in the season. The heat maps show the same story: down and away with fastballs and sliders to righties was a problem for him late in the season.
It looks like the young Astro has identified the mechanical issues at play. Additional good news is that traditional underlying statistics all speak in his favor, as he had a top-quartile strikeout minus walk rate, a top-10 ground-ball rate, plus velocity and poor numbers in the peripherals with the most noise (batting average on balls in play, strand rate and home run rate). There are a couple of ways to make this argument for Brown.
2023: 5.72 ERA
2024: 4.25 ppERA
With a fastball sitting close enough to 94 mph to round up, and superlative strikeout rates in the minors with large innings totals, it’s pretty easy to see why Pfaadt came touted as a ready-made prospect when he made his debut last year. Unfortunately, his four-seam fastball has poor shape — it has below-average ride without much horizontal movement — and his changeup and curve are middling, so all the pressure was on his sweeping slider, which has poor platoon splits. He was suddenly a one-pitch pitcher, flailing especially against lefties.
It all started to change when he began throwing this sinker, which registered as an average sinker by Stuff+.
Against righties, Pfaadt was suddenly much better off. Their slugging percentage against him dropped three hundred points after the rookie started throwing the sinker. You saw that in his excellent postseason run, too, when he threw 22 innings with a 3.27 ERA and struck out 30 percent of the batters he saw, which aligned well with his minor-league results.
But he wasn’t as strong against lefties in the regular season, or even in the postseason when it seemed like he was just trying to outlast the big lefty sluggers. The hope might be in his least-used pitch, the curveball. Lefties didn’t hit the curve well, while they slugged .583 off the changeup. Being mostly four-seam/curve against them, with the odd changeup and sweeper mixed in, might be a better approach, provided he can improve his command of the curveball (92 Location+).
Still, near-dominant against righties with the raw material to improve against lefties — that’s something exciting.
(Photo of Hunter Greene: David Butler II / USA Today)