Projecting the futures for Jacob Misiorowski, Chase Burns, Mick Abel and more rookie pitchers

Watch one highlight, and you might be certain that this rookie pitcher is on his way to sustained success in the big leagues. For example, this devastating, 96-mph slider from Jacob Misiorowski to Willi Castro appears to answer all the questions about Misiorowski’s future.

But the truth is that no matter how good their raw stuff is, rookie starters have a lot of work to do if they want to figure out what will be successful, year-in and year-out, against major-league hitters.

“Before, I was thinking like a reliever; I’m just going to throw my best s— as long as I can,” Clarke Schmidt said last year about that process. “But now, I’m like oh my god, I need to think about all five or six innings. The Stuff+, maybe now I’ll get dinged on it a little, but it’s a better overall plan and will lead to better on-the-field true results. The computer says you have to use it, but then you get on the field and you figure out it doesn’t always work that way. You have to keep the hitters off-balance. You need those tools to develop the pitches, and you also need to develop some pitchability.”

Last year’s rookie starting pitchers were a bumper crop in pitchability. Paul Skenes sat obviously atop the heap, but Spencer Schwellenbach, Shota Imanaga, Luis Gil, Jared Jones, Spencer Arrighetti, and Hayden Birdsong were all successful, to varying degrees, and look like they have staying power in the big leagues.

They don’t have all that much in common in terms of age, arm slots, or skillsets, but there are a few aspects that look similar across the board. Last year’s rookies all:

• Had opportunity — a depth chart that needed them
• Had at least one plus-plus secondary pitch by Stuff+
• Either had a fastball or slider (additionally) that was above-average by Stuff+

Of course, if you sort last year’s rookie pitchers by this rubric, you have to add pitchers like Cade Povich, Jonathan Cannon, Cooper Criswell and Randy Vasquez, so just having these things does not mean long-term success is definitely in the cards. Those pitchers are still inconsistent and in the midst of proving themselves.

Appraising this year’s crop of young pitchers will take more than just a rubric. Let’s keep those commonalities in mind while we take a look under the hood.

Jacob Misiorowski, Milwaukee Brewers

There really isn’t much to question about Misiorowski’s stuff. He’s been sitting at 100 mph with top-five extension with a 95-mph slider that gets nine inches off drop off his fastball and an 88 mph curveball with elite spin and tons of drop despite the huge velo. Even the changeup looks good in the models. He leads all starters in baseball with a 128 Stuff+ (ahead of Hunter Greene’s 125), which is nearly three standard deviations from the norm. The stuff is elite.

The question is, of course, the command. He received below-average command grades from almost every prospect analyst, walked 14 percent of the batters he saw in the minors, and has so far put up an 88 Location+ (a count- and pitch-type adjusted command grade) in the big leagues. Not a single qualified starter since Location+ was born in 2020 has been under 90, which is bad news. But the lowest Location+ qualified seasons are not that depressing. Take a look:

Once you compare the young Brewer to pitchers with elite stuff along with their poor Location+, you see that the command may affect him from time to time, but probably won’t keep him from even putting up Cy Young-worthy seasons. He probably has another 60-70 great innings in him this year, and a fun career ahead of him, even if there’s a fair amount of health risk associated with inconsistent command and a mid-nineties slider. Castro will have plenty of company.

Chase Burns, Reds

This is being written before Burns’ start against the Yankees Tuesday night, which is dangerous, but at least we have some tools we can use from his time in Triple-A that reach beyond his results on the field. He already shows up on a fun list, the top ten starters in Triple-A by Stuff+. I’ve removed rehabbers.

These numbers are set against major league results and there’s a tight correlation between minor and major league Stuff+ for each player, so this is a lot of good news for Burns, as the stuff comes as advertised.

One surprising thing, given his velocity, is that his fastball Stuff+ is only around average (96), but he locates it and the slider well enough that it looks like he has a solid foundation. How he uses his slider against lefties, and how hitters see that fastball, will be the key components for his future. He starts with three really tough opponents, so the key will be watching those questions even if the top-line results aren’t as exciting as the stuff.

(After seeing that superlative start to his career, it’s certainly possible Stuff+ was missing something about his minor league fastball — the major league model does have arm angle while the minor league model has to predict an arm angle from release data — but it’s also important to remember that he sat around 97.5 mph in the minors and that he was up just about what you might expect in a debut, when pitchers traditionally are about a tick or two hotter than usual.)

Mick Abel, Phillies

Stuff+ beats the other most powerful predictor, K-BB, in samples as small as the one Abel has so far in the bigs. Which is good, because with an 18 percent strikeout and a four percent walk rate, Abel would only grade about average. He doesn’t seem average, though. Each of his pitches has something going for it:

• He sits 96 on the fastball, with an elite 2.5 inches of movement over expected given his low arm slot
• He sits 87 on the slider, with more drop than average
• He sits 82 on the curveball, with good two-plane movement
• His 89 mph changeup gets 13 inches more drop than his four-seamer

The movements on his pitches on Baseball Savant are not bright red, but the fact that he’s near average at all on vertical movement, with a low 29 degree arm slot, makes him funky to hitters. His fastball has the same approach angle, from almost the same arm slot, as the one thrown by Jacob deGrom.

Two breaking balls that rate well, two good fastballs with disparate shapes — Abel has everything he needs from a stuff angle. Despite some comically low command grades, and inconsistent walk rates in the minors, so far this has been the best stretch of his career when it comes to placing the ball. Until his last start, when he told reporters that “fastball command in general” was the problem. I think he’ll figure it out.

Kumar Rocker, Rangers

Last year, Rocker fit all the requirements we set forth and still had a really tough time. That was because his fastball had a sinker shape to it that made it vulnerable to lefties. The Ranger starter had no answer for southpaws, allowing an 18 percent walk rate to them. This year, he’s got that walk rate down to a manageable nine percent thanks to a new pitch he wasn’t considering as recently as this spring: a cutter.

“It’s a feel pitch for me,” he said in March, “and I don’t have the feel for it yet.”

In his last three starts, he’s thrown it more than a third of the time, and it’s shown above-average Stuff+ with good locations, to boot. Looks like he’s got the feel for the pitch. Lefties have still slugged .467 against him, but that’s progress. And now you can say that he not only has an elite breaking ball but he has an above-average fastball *no matter the handedness of the hitter at the plate,* which might have to be an addendum to our list of requirements.

Rocker is still risky because his best secondary is a breaking ball, and lefties are still seeing him well, but he took a huge step towards consistency by adding the cutter.

Didier Fuentes, Braves

After starting the season in High-A, Fuentes has rocketed through the Atlanta system all the way to the top. Some portion of that is need, as injuries have piled up around him, but not all of it. He’s moved past previously well-regarded prospects like Hurston Waldrep, and a lot of that probably has to do with his tantalizing combination of stuff and command. Having the best location numbers of the top ten Triple-A starters in stuff is a great start.

Not only does the righty bring the gas (96 mph on the fastball), but the funk is there too. Because he gets 17 inches of vertical movement on his fastball from a 32 degree arm angle, he has a whopping 2.8 inches of movement above expected (AKA dead zone), which is more than deGrom, and a little less than Hunter Greene. Here, the concern is that the secondaries — a sweeper and a two-plane curveball — would both work better against same-handed hitters, and he doesn’t seem to trust the split-finger.

That might be more of a theoretical weakness, though. Lefties so far don’t have a hit off of the 12 curveballs they’ve seen. They also don’t have a whiff. Can this pitch be his out-pitch against lefties?

With command like that, maybe!

Michael McGreevy, Cardinals

Another pitcher throwing on Tuesday as this article is written, at least McGreevy has given us some major league sample to work with. And so far the models are hand in glove with what prospect analysts had in store for him. FanGraphs had only the slider as an above-average pitch, but with 60 future command. Keith Law pointed out that his slider is good but that the change needs work if he’s going to get lefties out. Stuff+ says he’s got below-average stuff but Location+ says he has excellent command (123 Location+, which would easily lead all qualified starters if it held up).

Despite his good results so far, that’s a tough profile to pull off. He doesn’t have a secondary with a Stuff+ over 100. There have been 293 qualified pitcher seasons in the Stuff+ era and only 42 of them shared that concern. 16 of those 42 had an ERA over four and a half. Only José Berrios, José Quintana, Brady Singer, Robbie Ray and Pablo López managed the feat twice without having a disaster season on their record. With a sinker as his best fastball, it’s possible that Singer is the comp here, but there’s no obvious pathway forward for the young righty when seen through these terms.

The lefty concern is real, too. They are slugging .484 against him so far and his plan seems to be to throw mostly four-seamers and cutters with a mix of his poorly-performing changeup and curveball. When you look at those pitchers, they mostly throw four-seamers or have decent changeups or do both.

With command as good as McGreevy’s none of this impossible. But it’s also important to look past the surface-level results, because this is going to be a tougher road to hoe than it first appears.

Noah Cameron, Royals

Velocity isn’t everything. The whole point of stuff models is to account for the importance of shapes. Strangely enough, though, Cameron features below-average movement in a lot of ways:

• His fastball has less ride and fade than the average fastball
• His changeup has less drop and fade than the average changeup
• His slider has less velocity and less cut than the average slider
• His curveball has much less sweep than the average curve

He throws from over the top, so it’s not surprising that he doesn’t get any side-to-side wiggle, but then you’d expect more ride.

And then there’s the velocity. While 92 mph doesn’t sound bad, of the 175 qualified pitcher-seasons in the last three years, only 23 have had velo that low. The good news is that fellow lefties Shota Imanaga and Justin Steele are on that list, the bad news is that Patrick Corbin is on the list repeatedly.

There’s some value to just being a lefty, though. Lefty starters are rarer than ever, and only two lefties throw from a higher angle, so he’ll get some weird looks from the box. Despite below-average strikeout rates (19 percent), his lefty velocity comps have put up a 4.27 ERA. That’s about what I’d expect long-term for Cameron.

Jacob Lopez, Athletics

This 27-year-old lefty sits 91 from a low slot: only six lefties throw from a lower slot, so there’s some rarity for you. Otherwise, though, everything is mostly east-west in a way that hitters would expect from the slot. A cutter with a little more ride than expected still comes in at 88, and the changeup has a little more drop this year, but the velocity really limits the upside, as we just heard. Lastly, Lopez pitches in Sutter Health Park, in which the environmental factors are adding 11.5 feet on batted balls, second only to Coors Field — and this is before it’s really getting hot there. “Coors California” is not going to be kind to middling stuff in July and August.

(Photo of Misiorowski: Patrick McDermott / Getty Images)