Since the Atlanta Braves moved him to the starting rotation at the beginning of the 2022 season, Spencer Strider has been one of the best pitchers in all of Major League Baseball. With an electric four-seam fastball and devastating slider, Strider was a strikeout machine in 2022 and 2023, posting a strikeout rate of at least 36% in each season, while finishing 4th in the National League Cy Young Award voting in 2023. While he was hoping to build upon his impressive 2023 results with a strong 2024 campaign, Strider injured his UCL in his second start of the season, resulting in an internal brace operation and an end to his 2024 season. Upon returning from injury in 2025, Strider has struggled, with a sharp decline in his strikeout and walk rates driving a regression in his overall level of production. This article will take a look at the differences in Strider’s arsenal since his 2023 season, identify potential areas of improvement, and attempt to discern whether Strider’s slow start is a temporary blip or a sign that he has lost his stride.
Overview
Since leaving the bullpen at the beginning of the 2022 season, Strider has been one of the best pitchers in all of Major League Baseball. In 2022, his first season as a starter, Strider produced a 38.3% strikeout rate, 8.5% walk rate, and 1.83 FIP over 131.2 innings pitched, leading all of Major League Baseball in K-BB% (minimum 130 innings pitched) and producing 4.9 fWAR. Strider built upon this impressive debut with a 36.8% strikeout rate, 7.6% walk rate, and 2.85 FIP, producing 5.5 fWAR and finishing 4th in the National League Cy Young Award voting.
So far this season, Strider has been off to a slow start, currently producing a 22.4% strikeout rate, 10.3% walk rate, and 5.55 FIP over his first 25.0 innings pitched. While a decline in performance can be expected after returning from a long-term injury such as a UCL injury, and 25 innings is a small sample size, the sharp decline in production that Strider has experienced this season has raised concerns regarding whether he will be able to reclaim his prior levels of success moving forward. Let’s dive into how Strider’s pitch mix has evolved since his stellar 2023 season, and whether those changes might explain his sudden drop in effectiveness.
Arsenal
As mentioned previously, Strider’s arsenal is built around an electric fastball-slider mix, which has historically been extremely effective at generating swing-and-miss and producing strikeouts. Evaluated as an 80-grade pitch upon graduation from prospect status in 2022, Strider has relied heavily on his four-seam fastball throughout his Major League career, utilizing the pitch 67% of the time in 2022, and 58.9% of the time in 2023. On the macro level, Major League Baseball has been trending away from four-seam fastball usage over the past couple of seasons, however, the high quality of Strider’s fastball historically allowed him to rely heavily on the offering and still be effective.
As shown by the movement plot above, Strider displayed the definition of a plus-plus fastball in 2023, with 18.4 inches of induced vertical break and 6.1 inches of arm-side movement at a 48-degree arm angle. When combined with his low release height, -4.5 degree VAA, and 1.5 adjusted VAA, Strider’s fastball was nearly untouchable when located at the top of the strike zone, as these factors combine to create a “rising” effect, resulting in opposing hitters to swing under the pitch. At 85.6 MPH and 5.6 inches of glove-side movement, Strider’s slider displayed above-average shape and was able to “play up” due to tunneling and deception effects likely created by opposing hitters frequently anticipating Strider’s fastball. When hitters were anticipating 98 at the top of the zone and instead got an 85 MPH slider at the bottom of the zone, the results were devastating, with the pitch generating a 55.3% whiff rate in 2023.
The table above depicts how Strider’s arsenal graded out in two major pitch quality models (FanGraphs’s Stuff+ and StuffBot) during the 2023 season, alongside his current stuff grades (presented as 2023 grade / 2025 grade). Stuff+ and StuffBot were both big fans of Strider’s fastball in 2023, with the pitch grading as a 118 Stuff+ and 67 StuffBot, nearly two standard deviations above average. The models differed in their opinions on Strider’s slider, with Stuff+ grading the pitch as a 120 and StuffBot grading the pitch as a 52. The models also differ in their opinion of Strider’s changeup, with the pitch being awarded a 96 Stuff+ and 62 StuffBot in 2023.
While Strider’s 2023 arsenal featured some of the most dominant pitches in Major League Baseball, this high level of pitch quality has not carried over into 2025. Across the board, Strider’s stuff metrics have declined since returning from his internal brace surgery, with, most notably, the four-seam fastball declining from a 118 Stuff+ in 2023 to a 94 so far in 2025. StuffBot agrees with this regression, dropping its grade from 67 to 50. Similarly, Strider’s slider has declined from a 120 Stuff+ to 99, and from 52 to 42 according to StuffBot.
Why has Strider experienced such a sharp regression in pitch quality in 2025? The table above depicts Strider’s movement plots from the 2023 and 2025 seasons, displaying the primary difference in the quality of Strider’s pitches which has been the all-around decline in average velocity. The average velocity on his four-seam fastball has declined from 98.1 MPH in 2023 to 95.5 MPH in 2025, while his slider’s average velocity has also declined from 85.6 MPH to 83.6 MPH so far this season. This decline in velocity has allowed opposing hitters to better “time up” his offerings, minimizing his ability to generate swing-and-miss, and reducing his strikeout rate.
Returning from a serious injury, such as a UCL tear, is a difficult task for any pitcher, and perhaps the most difficult part of recovery for a pitcher is attempting to regain their prior levels of velocity. While the rate of success for UCL operations has increased over time, research suggests that it typically takes most pitchers a couple of seasons to return to “full form” post-operation. This makes depending on pitchers to return to their pre-injury level of performance immediately after returning from the injured list particularly risky, as they are likely to experience a decline in pitch quality upon return, negatively impacting their on-field results.
Strider’s predominantly two-pitch mix has also left him vulnerable to this level of volatility upon returning from injury. In recent seasons, a common trend throughout baseball has been that pitchers have been widening their arsenals, diversifying their pitch mixes to utilize multiple pitches that perform better against hitters of a specific handedness. One benefit of possessing a wide arsenal is that if the quality of one pitch declines, the pitcher can more easily “mask” this weakness by increasing the usage of the other pitches in their arsenal. While having two plus-plus pitches in your arsenal as a starting pitcher (as Strider did in 2023) can lead to some gaudy strikeout totals, it can also increase the volatility of a pitcher’s arsenal, as once one pitch begins to decline, there are few backup options to rely on to “mask” this newfound weakness. While this decline in four-seam fastball has a negative effect on Strider’s arsenal in a vacuum, his inability to rely on a different fastball and/or throw multiple fastballs has compounded this issue, forcing Strider to throw a sub-optimal fastball which hitters can more easily “time up”.
Strider has attempted to diversify his arsenal in the past and, as shown by the table above, has added a curveball to his pitch arsenal. This offering was added to his arsenal before the 2024 season in an attempt to provide him with an offering that he could utilize early in the count to generate called strikes. While it was a reasonable idea for him to proactively attempt to diversify his arsenal, Strider has experienced difficulty locating the curveball, with the pitch currently generating a 55 Location+ and a 20-grade score by CommandBot.
While this decline in velocity had led to a broader decrease in overall production, Strider has especially struggled against left-handed hitters so far this season. As shown by the table above, Strider is currently producing a 16.7% strikeout rate, 10% walk rate, and 6.8% K-BB against hitters of the opposite handedness in 2025.
This decline in strikeout ability can largely be attributed to the fastball’s inability to generate swing-and-miss, as the whiff rate on Strider’s four-seamer has declined against left-handed hitters from 27.3% in 2023 to 14.3% in 2025. Strider has continued to rely heavily on his four-seam fastball to left-handers as he did in 2023, with the pitch’s usage rate > 50%, and the declining velocity of the offering has allowed for left-handed hitters to “sit on” and produce damage against the offering. Strider has also been generating fewer chases on his slider against left-handed hitters, reducing the offering’s whiff rate from 48.2% in 2023 to 36.7% in 2025. As a result of these worsening splits, opposing teams may now feel more confident stacking left-handed hitters in the lineup against Strider, further increasing the exposure of his most vulnerable offerings.
As mentioned earlier, Strider’s ability to locate his curveball has been underwhelming to begin 2025, and this trend has continued across the entirety of his arsenal to begin 2025. As shown by the table above, Strider has featured declined Location+ and CommandBot scores across this season, a major contributor to his > 10% walk rate against hitters of both handedness. Location grades can display variance within a season and are less stable than stuff grades, providing optimism that Strider could potentially experience some positive regression in this area, however, the combination of decline in stuff and command ability has led to a substantial decline in overall production to begin the season, and it appears that Strider will need to make a major adjustment to his current arsenal or approach to reclaim his prior levels of success.
Moving Forward
To return to his pre-injury self, Strider will need to either increase his average velocity to his pre-injury levels or he needs to diversify his pitch arsenal and add multiple fastballs to “mask” the current vulnerability he is displaying on his four-seam fastball. Increasing average velocity during the season is incredibly difficult, as this would require targeted training, with such an improvement likely waiting until the offseason and not being able to materialize on-field until 2026, at the earliest. In my opinion, adding multiple fastballs to his arsenal would be the best course of action to take, particularly a cutter, which would provide him with an offering that he can utilize to generate sub-optimal contact against left-handed hitters, and allow for his fastball to “play up”, as hitters would have to distinguish between multiple fastballs in Strider’s arsenal. A main challenge to adding an additional fastball to his arsenal is that Strider has displayed pronation bias throughout his career, and pitchers with this bias tend not to effectively add cutters and/or sinkers to their arsenals due to the difficulties they experience in generating seam-shifted wake. Perhaps Strider could still attempt to add these pitches to his arsenal, however, his inability to effectively add additional pitches to his arsenal throughout his career, points to this being an unlikely solution.
Frankly, Strider’s outlook for the remainder of the 2025 season does not look bright. Taking a look at “traditional” indicators of future regression, Strider is currently producing a .254 BABIP, a 69.0% LOB, and a 14.7% HR/FB, indicating that, if anything, he has been slightly “lucky” on balls in play and slightly “unlucky” with runners left on base and home runs allowed. Strider’s next start is on Saturday at home against the Colorado Rockies, and this outing will either boost his confidence that he can reclaim his prior levels of success with a good outing, or raise even more “red flags” about his rest of season performance with an underwhelming outing. In addition, the struggles that Strider has experienced so far this season raise questions about how well pitchers with smaller arsenals return from UCL injury, and perhaps further research into this topic would suggest that pitchers with larger arsenals are better prepared to withstand the declines in velocity that occur post-injury.
In conclusion, Spencer Strider has had a difficult start to his 2025 season. Strider may regain his velocity with more time and a healthy offseason, potentially making this article look premature, however, based on his 2025 performance to date, with diminished velocity, reduced pitch quality, and an unclear blueprint for improvements moving forward, it’s fair to say that, at least for now, Spencer Strider has lost his stride.
Statistics as of the end of play on June 11th, 2025.
Photos by David J. Griffin/Icon Sportswire and Annie Spratt/Unsplash | Featured Image by Ethan Kaplan (@djfreddie10.bsky.social on Blue Sky and @EthanMKaplanImages on Instagram)
