When scouting pitching prospects, evaluators are tasked with giving a pitcher a grade on the 20-80 scale for each of their pitches. At the beginning, it was standard to only judge a pitcher on their velocity when looking at their pure “stuff”, but now, that appears to be changing. With more teams focusing on different aspects of pitch data, it’s clear that there is much more of a distinction between what they are looking for in a pitcher. Today, we’ll be looking at different aspects of pitching – velocity, spin rates, pitch usage – and try to identify the ideal traits that teams should covet with their pitchers.

For this study, I utilized Baseball Savant’s custom leaderboard tool, and compared different variables’ relationship to expected-weighted-on-base average allowed (xwOBA); the goal of this study is to find a common trait that most successful pitchers share. After doing so, here were my main takeaways:

• 4-Seam Fastball Velocity and Vertical Movement each had a coefficient of determination of 0.21 when compared to xwOBA allowed, meaning that both are equally important in projecting future success.
• Interestingly, there wasn’t much of a trend between any of the variables with off speed pitches besides a small correlation for a slider’s vertical break. Obviously, having adequate off-speed pitches is important, but it’s clear that their main significance is how to play off of a fastball.
• In general, there isn’t any optimal pitch usage model for pitchers to follow. Different pitchers should attack hitters in different ways, which is where having a progressive organization looking at a hitter’s strengths and weaknesses, as well as a pitcher’s feel for pitching, comes into play.

However, what I found most intriguing was how sinker and cutter usage correlates to xwOBA allowed. Several organizations have really de-emphasized those pitches in favor of a rising fastball at the top of the zone, and it’s clear to see why:

Graphs Provided By Baseball Savant

Not only do cutters and sinkers not generally correlate with future success, but, although it isn’t by a convincing margin, throwing those pitches more may actually correlate with a lack of success. Although this may appear to be strange on the surface, it actually makes a lot of sense. At this point, most baseball fans are well aware of the growth of launch-angle-oriented swings, which have played a part (among other factors) in the increased rate of home runs- more fly balls are being hit, thus there are more opportunities for more power production. Therefore, rather than pitching down in the zone and working right into the wheelhouse of the modern-day swings, pitchers really need to be working up in the zone. As a result, unless you can guarantee perfect command, sinkers and cutters don’t tend to be effective pitches.

So, by now, we’ve discovered that a vertical-moving fastball with off speed pitches that can complement it is the ideal pitch mix, while sinkers and cutters should be de-emphasized. Taking that into account, we can specifically identify pitchers who have untapped potential, should they change their pitch usages. There isn’t a perfect pitch usage model that each player should follow, but generally, it’s common sense that you should throw your better pitches more, and your worse pitches less. With that mind, there are 35 pitchers that fit the bill we’re looking for.

Before we examine these 35 pitchers, let’s place them into specific categories;

1. Pitchers Who Need To Go From Down To Up: These pitches are relying too much on sinkers/cutters and have the traits needed to adopt a fastball that works at the top of the zone. As we’ve seen with Justin Verlander, Gerrit Cole, and Tyler Glasnow, these pitchers generally have the most upside, though they also may be the most risky group, since you’d be asking pitchers to do something they may not be able to do.
2. Pitchers Who Have One Elite Pitch They Need To Use More: If all goes well, these pitchers can rely more on a specific pitch that they have a lot of success using and not lose any efficiency. At the same time, there is a chance that if hitters anticipate the pitch more, it’ll lose its effectiveness.
3. Pitchers Who Need To Rely on Off-Speed More/Less: This group of pitchers have the least amount of room to improve, but they also may be able to make subtle improvements to increase their production. They have the arsenal of pitches to succeed, but just have to use them in a different way to be more successful.

Some pitchers fall into two categories, so when that’s the case, I classified them with the group that they identified the most with. In general, those types of pitchers probably have the most room to improve, but since there are multiple moving parts associated with them maximizing on their abilities, they are probably at the greatest risk of “failing”.

Pitchers Who Need To Go From Down To Up

• Tanner Roark, Toronto Blue Jays: Roark’s fastball hasn’t had much success in the past, but neither has his sinker. He has the vertical movement pattern necessary to work more at the top of the zone, though he also would benefit by throwing his curveball, his most effective pitch, more often.
• Zack Wheeler, Philadelphia Phillies: Wheeler may be the pitcher in this article that I’m the most excited about. He throws a hard fastball that is meant to work at the top of the zone, yet is throwing it nearly as much as his sinker, which wasn’t an effective pitch when he was with the Mets. However, after signing a five-year contract with the Phillies, a more progressive organization, he’s in a good position to change his pitching strategy.
• Martin Perez, Boston Red Sox: Perez is an exception to the “cutter rule”, as he actually throws an effective cutter. In general, though, his main problem is his sinker, which he’d be better off getting rid of entirely.
• Marco Gonzales, Seattle Mariners: Gonzales is known as a sinker-baller, but it’s by far his worst pitch. He has shown the traits to be more of a vertical pitcher, and becoming that would be best for him.
• Mike Soroka, Atlanta Braves: He’s coming of an excellent rookie season, but Soroka’s peripherals didn’t match up with his ERA, and continuing to rely on his sinker would be an ill-fated decision. He’d be best off embracing his spectacular breaking pitches, while also becoming more of a 4-seam-centric pitcher.
• Dakota Hudson, St.Louis Cardinals: Similarly to Soroka, Hudson’s peripherals don’t match up with his ERA at all, and his sinker got absolutely ambushed last season.
• Sandy Alcantara, Miami Marlins: Alcantara needs to use his slider more, but with his high-90s velocity, he theoretically should also be working at the top of the zone more than he currently is.

Pitchers Who Have One Elite Pitch That They Need To Use More

• Trent Thornton, Toronto Blue Jays: Thornton is coming off of a poor rookie season, but I believe that he some potential that hasn’t been tapped into. His slider has excellent movement, but he didn’t utilize it enough.
• Zack Davies, San Diego Padres: After being traded to the Padres, perhaps Davies can make the changes he needs to make. His curveball was a strong pitch for him in 2018, but he de-emphasized it in 2019, and even though hitters mashed it the 3% of the time he threw it, he should go back to relying on the curveball more.
• Brad Keller, Kansas City Royals: Keller has an elite slider, yet he doesn’t use it enough. More sliders and less sinkers- simple enough, right?
• Joey Luchessi, San Diego Padres: Luchessi is an interesting case study. His changeup is incredible, but he doesn’t have any other pitches to complement it. Building off of the changeup more with an actual fastball or breaking ball will be the key for future success.
• Julio Teheran, Los Angeles Angels: Teheran is one of the few pitchers who have actually done better with a sinker than 4-seam fastball, as he lacks vertical movement on the latter pitch. It’d be risky to increase his usage of that pitch however, so I’d prefer if he altered his pitch mix with more changeups.
• Marcus Stroman, New York Mets: Stroman’s sinker-cutter combination is really holding him back. He’s about to be a free agent, and if I were a team considering signing him, I would have him rely on his slider, which is an exceptional pitch, as well as implement a curveball to complement it.
• Mike Fiers, Oakland A’s: Although he’s a veteran without great peripherals, Fiers could be even better if he utilizes his curveball more. Both from the metrics and the eye test, it’s a really nice pitch.
• Mike Mikolas, St.Louis Cardinals: Mikolas has a five-pitch mix, but it isn’t working as well as it could. His curveball is clearly his best pitch, so he should use it more.
• Steven Matz, New York Mets: Matz throws his sinker 50.6% of the time, and it’s a bad pitch. Meanwhile, he has a curveball has had an xwOBA allowed of .237 or lower in each of the past two seasons, yet is only throwing it at a 14.9% rate.
• Patrick Corbin, Washington Nationals: Corbin has had plenty of success thanks to his slider, which is one of the best pitches in the MLB. However, since all of his other pitches he has are well-below-average, he may want to either use the slider more, or work on a way for his pitches to better complement the slider.
• Madison Bumgarner, Arizona Diamondbacks: Similarly to Zack Wheeler, I actually think Madison Bumgarner will be altering his pitch usage- he signed with a very progressive organization in the Diamondbacks this offseason. If he throws his curveball more, he could increase his strikeout rate further.
• Jon Lester, Chicago Cubs: Just like with Bumgarner, Lester should be throwing all of his other pitches less, and his curveball more.
• Mike Leake, Arizona Diamondbacks: Leake’s xwOBA allowed on sinkers last season was nearly .500 last season, which is absurdly bad. Throwing his curveball more, and doing whatever it takes to throw the sinker less, is a necessity for him.
• Merrill Kelly, Arizona Diamondbacks: Yet another Diamondback pitcher on this list, Kelly’s curveball was his best pitch last year, so he should use it more often.

Pitchers Who Need To Use Their Off-Speed Pitches More/Less

• Yu Darvish, Chicago Cubs: Darvish is cited to have as many as ten different pitches, but how he uses them is still not 100% correct. He’d be better off relying on his breaking pitches more.
• Kyle Gibson, Texas Rangers: With a poor sinker, Gibson could classify in the first tier, but he doesn’t really have the velocity or movement to be a candidate to work in the top of the zone. At the very least, he can improve by becoming a breaking ball-centric pitcher.
• Hyun-Jin Ryu, Toronto Blue Jays: Although he had an excellent ERA last season, a change in pitch usage could elevate Ryu’s strikeout rate. He needs to throw less cutters and sinkers, and replace them with more breaking balls.
• Trevor Bauer, Cincinnati Reds: Considering how smart of a pitcher he is, it’s surprising to see Bauer is on this list. His cutter is an ineffective pitch, and considering how strong of an offering his slider is, it isn’t really a useful pitch.
• Jakob Junis, Kansas City Royals: Junis is another Royals pitcher who throws his sinker a lot, and just like with Brad Keller, it isn’t working. Luckily for Junis, though, his changeup and slider are tremendous pitches.
• Joe Musgrove, Pittsburgh Pirates: All of Musgrove’s off-speed pitches grade out well, so he simply needs to throw his fastball less.
• Walker Buehler, Los Angeles Dodgers: Buehler is thought of as one of the top young pitchers in the MLB, but even he could be better. By throwing less sinkers and cutters in favor of more breaking balls, he may finally become a true ace.
• Kyle Hendricks, Chicago Cubs: Although his command is really strong, Hendricks still hasn’t gotten optimal results from his sinker recently. He should be throwing more curveballs and changeups.
• Matthew Boyd, Detroit Tigers: Boyd’s fastball got absolutely demolished last season, but his slider and changeup grade out really well. He’s an intriguing trade target for a progressive organization that can help him alter his pitch usage.
• Dylan Bundy, Los Angeles Angels: Due to a unsustainably poor HR/9 in Baltimore, many see Bundy as a bad pitcher. Yet, I actually think he’s a quality option, especially if he throws his fastball a lot less. He was a nice addition by the Angels.
• Max Fried, Atlanta Braves: The peripherals suggest that Max Fried is already the best young starting pitcher on the Braves. However, he has a true gift with an exceptional curveball, as well as a slider that plays off of it, so he should use both pitchers more often.
• Sonny Gray, Cincinnati Reds: The Yankees tried to make Sonny Gray a fastball-reliant pitcher, and the results were terrible. He improved his pitch usage with the Reds, but he still could throw the fastball less- his breaking balls are terrific strikeout pitches.
• Aaron Nola, Philadelphia Phillies: Nola is trying to become more breaking-ball centric based on the changes in his pitch mix, but he could become even more extreme in that area.
• Jose Berrios, Minnesota Twins: Berrios has never seemed to take the next step to becoming a true frontline starter, but utilizing his curveball and changeup more often would help him in that regard.
• Eduardo Rodriguez, Boston Red Sox: Rodriguez is the one young pitcher that the Red Sox can build around, and Chief Officer Chaim Bloom taking over, hopefully the organization can assist him in relying more on his off-speed pitches.

There isn’t a standard pitch frequency chart that players can follow, but for these 35 pitchers, they’re currently leaving potential upside on the table with the current pitch usages. In general, though, it appears that teams should be looking for pitchers who are capable of working at the top of the zone, and with off-speed pitches that can complement it. Of these 35, Zack Wheeler, Trent Thornton, Marcus Stroman, Brad Keller, Jakob Junis, Steven Matz, Max Fried, Matthew Boyd, and Dylan Bundy are the nine pitchers that intrigue me the most, especially if they can either somehow find their way to a more progressive organization, or make necessary adjustments on their own; all are definitely intriguing, however. Although it’s very difficult to have the perfect pitching arsenal, while also having a 100% correct pitch frequency mix, pitchers should try to follow the new golden rule for pitching: don’t work down in the zone.