Over the past few seasons, much of the discourse regarding the analysis of Major League pitchers has revolved around analyzing the quality of a pitcher’s “stuff”. The advent of pitch quality models, such as Stuff+, which evaluate pitches solely based on their velocity, spin, and movement characteristics, has spearheaded this trend, largely due to the predictive power of these models. While Stuff+ models are incredibly powerful tools to evaluate a pitcher’s performance and to predict their production moving forward, these models do not fully describe how well a pitcher performs in a given outing. For this reason, models such as Pitching+ and PLV also take into account the final location of each pitch in addition to the pitch’s “stuff” characteristics. While less predictively powerful than location-agnostic models, due to the inherent difficulty in commanding a baseball, the final location of each pitch tends to be the most important feature as it pertains to awarding a pitch a given pitch quality value.
Displaying the ability to effectively locate your offerings is a particularly important attribute for a starting pitcher, as they have to face a lineup multiple times and can’t rely solely on their “stuff” the same way max-effort relievers can without increased risk of fatigue and/or injury. While displaying premium “stuff” is still quite valuable as a starting pitcher (with the best starting pitchers in Major League Baseball such as Tarik Skubal and Jacob deGrom displaying above-average stuff and location ability) it is possible for a starting pitcher to still provide significant value to their rotation by displaying consistent high levels of location ability, while displaying “stuff” around league-average.
An example of a pitcher who has fit this archetype so far this season has been Janson Junk of the Miami Marlins. Signed by Miami as a minor league free agent in February, Junk has done nothing but produce in his 13 appearances at the Major League level (8 as a starter, 5 as a “bulk” reliever). Over 65.1 innings pitched in 2025, Junk has produced an 18.3% strikeout rate, 2.3% walk rate, and a 3.86 ERA, accumulating 2.0 fWAR for the Marlins so far this season. Junk’s 2.40 FIP ranks as the 2nd-lowest in all of Major League Baseball among pitchers with at least 60 innings pitched, alongside Tarik Skubal (1st with a 1.95 FIP) and Paul Skenes (3rd with a 2.40 FIP). Junk’s extraordinarily low walk rate is a reliable surface-level indicator that he possesses excellent command that allows him to throw his pitches to ideal locations, however; an under-the-hood look at Junk’s arsenal appears necessary to fully understand how he has achieved this level of production so far this season.
As shown by the tables above, Junk’s arsenal consists of five pitches: a four-seam fastball, a slider, a sweeper, a curveball, and a changeup. Against right-handed hitters, Junk predominantly utilizes the four-seam, sweeper, and slider, while against left-handed hitters, Junk toggles up the usage of the curveball and changeup while rarely utilizing the sweeper. Junk has been more effective against right-handed hitters this season, producing a 20.6% strikeout rate, 1.5% walk rate, and 2.14 FIP against right-handed hitters while producing a 15.7% strikeout rate, 3.1% walk rate, and 2.71 FIP against left-handed hitters. Nearly all of his pitches grade exceptionally well by location models, with PLVLoc+ awarding each pitch besides his changeup an above-average grade. FanGraphs’ Location+ concurs with that assessment, with Junk’s 116 Location+ grading as the highest among pitchers with at least 60 innings pitched so far this season.
While Junk’s excellent ability to locate his pitches has been a major factor in his success so far this season, his pitches grade out around-average by pitch quality models such as Stuff+, StuffBot, and aStuff+, suggesting that Junk isn’t merely surviving on command despite poor stuff. Each model grades Junk’s curveball as his best pitch, with the offering displaying an 82.5 MPH average velocity with ~12 inches of drop. aStuff+ and StuffBot assess Junk’s stuff quality as league-average, while FanGraphs’ Stuff+ is a bit more bearish on the quality of Junk’s arsenal, with a 95 Stuff+.
One benefit of displaying excellent command ability is that it provides the pitcher with more confidence to locate their offerings in ideal locations that will maximize the pitch’s effectiveness. As shown by the location plots above, Junk has been consistent in locating his slider and sweeper down-and-away to right-handed hitters, and has also kept his curveball down in the zone where it can be utilized for swing-and-miss and sub-optimal contact, rather than leaking out towards the heart of the zone for damage. Junk’s four-seamer and changeup have been effective in their current locations so far this season; however, I believe there could be some more swing-and-miss upside present if Junk were able to locate his four-seamer up in the zone and his changeup more consistently down in the zone.
Another benefit of displaying plus command ability is the ability to get ahead in counts, forcing opposing hitters to stay defensive rather than sitting on a pitch they can produce damage on in hitter’s counts. Junk has been excellent at maximizing count leverage so far this season, and his ability to not get behind in counts has been a major contributor to his success so far this season. The table above displays how well Major League hitters have performed when they have been in different count states this season. For reference, early counts are 0-0, 0-1, 1-0, 1-1, leverage counts (“ahead” for the hitter, “behind” for the pitcher) are 2-0, 2-1, 3-0, 3-1, and two-strike counts are 0-2, 1-2, 2-2, 3-2. Opposing hitters swing the bat faster, make harder contact, and produce more damage when they are in leverage counts, indicating that there is value in a pitcher’s ability to avoid falling into these count states. The first step to avoid falling behind in the count is to throw a first-pitch strike, and Junk currently displays the 5th highest first-pitch strike rate in Major League Baseball at 70%.
Not only does Junk display an ability to throw first pitch strikes, but he has also demonstrated an ability to locate his pitches in the strike zone early in counts, with his 60.8% early-zone rate ranking as the 3rd highest in all of Major League Baseball this season. This combination of throwing first-pitch strikes and landing his early count pitches in the strike zone has allowed Junk to avoid falling behind in counts this season, with only 6.5% of his pitches thrown this season being in leverage count states, the lowest in all of Major League Baseball. Count leverage has been favoring Junk in a large proportion of his matchups so far this season, and this subtle advantage has allowed for Junk’s arsenal to “play up” above his surface-level pitch quality as a result.
Janson Junk’s mini-breakout has been an intriguing development to follow so far this season, and underscores the importance of command and location ability in the modern pitching analysis environment, which is dominated by “stuff”. While the on-field results Junk has displayed so far this season have been impressive, his peripheral metrics provide some insight into how sustainable Junk’s success will be moving forward. While Junk is currently underperforming his FIP (2.40 FIP, 3.86 ERA), ERA estimators indicate that his production has been aligned with his expected results, with Junk currently producing a 3.82 xERA and 3.83 SIERA. Junk figures to experience some positive regression as his 60.4% left-on-base percentage regresses closer to the league-average, while Junk’s extraordinarily low 2.6% HR/FB ratio figures to inflict some negative regression on Junk’s production, although I would imagine his plus count leverage abilities will allow him to maintain a low HR/FB ratio.
Projection systems are notably mixed when prognosticating Junk’s rest of season production, with ZiPS projecting Junk for a 3.97 ERA and OOPSY projecting Junk for a 4.51 ERA over the final two months of the season. I’m going to hedge my bets and ballpark Junk’s rest-of-season ERA to be between these two projections. Location ability is less predictive and experiences more start-to-start variability than stuff ability (hence the value of Stuff+ models), and I would imagine that Junk will have a start or two in the future where his location ability struggles and he falls behind in counts, leaving himself vulnerable to damage. With that being said, Junk has consistently demonstrated above-average command ability throughout his Major League career, indicating that his high Location+ scores are likely not a fluke. I believe that his ability to consistently get ahead in counts will allow him to continue providing serviceable innings to the Marlins rotation moving forward, a valuable attribute as a back-of-the-rotation starter, and a reminder of the power of command in a stuff-obsessed era.
Statistics as of the end of play on August 5th, 2025.
Photo by Icon Sports Wire | By Carlos Leano
