Early Foundations: The Development of deGrom’s Curveball

Jacob deGrom’s ascent from a low‑90s fastball reliever at Stetson University to a two‑time Cy Young Award winner with a historically dominant arsenal is a story of relentless pitch development. When the New York Mets drafted him in the ninth round in 2010, his curveball was an afterthought—a loopy, inconsistent offering that rarely forced a swing‑and‑miss. Scouts noted his fastball command and a developing slider, but the curveball lacked the tight rotation and late break needed to generate whiffs against professional hitters. Recognizing this shortcoming, both deGrom and the Mets’ player development staff made refining the curveball a priority during his minor‑league years.

After Tommy John surgery in 2012, deGrom returned with a changed perspective on grip and mechanics. He spent long hours at Double‑A Binghamton and Triple‑A Las Vegas working with pitching coaches to increase the pitch’s spin rate. The biggest breakthrough came when he switched from a standard four‑seam curveball grip to a modified knuckle‑curve, placing his index fingertip directly on the seam. This subtle change drastically increased revolutions per minute (RPM): his curveball’s average spin rate climbed from roughly 2,400 RPM to over 2,700 RPM during his minor‑league stint. By the time of his MLB debut on May 15, 2014, the curveball had already become a reliable third pitch—batters swung and missed at it more than 40% of the time in his first few starts. Still, it was used mainly as a change‑of‑pace offering to keep hitters from sitting on his fastball and slider.

The real transformation from solid third pitch to elite weapon occurred over the next several seasons. deGrom studied the pitch’s behavior in different counts, learned to adjust finger pressure for different situations, and worked to eliminate any mechanical tells. A critical moment came during spring training in 2017, when he adopted a grip that placed more pressure on the middle finger’s seam, creating a tighter 12‑6 to 11‑5 break depending on release point. He also began varying his grip based on the game situation: a slightly tighter grip for strike‑one curveballs to avoid over‑spinning, and a looser grip for two‑strike putaway sequences to maximize depth and horizontal movement. By 2018, his curveball averaged over 2,800 RPM with roughly 50 inches of vertical break from release to home plate—elite marks that consistently placed him among the top five starting pitchers in curveball whiff rate.

Refinement Through Data: Mechanics, Spin Axis, and Release Tunneling

From 2016 onward, detailed Statcast data illuminated how deGrom’s curveball actually worked. The pitch was not simply a high‑spin offering; it benefited from a well‑tuned spin axis and a release point that nearly perfectly matched his four‑seam fastball. This tunneling effect made it nearly impossible for hitters to differentiate the two pitches early in flight, forcing them to commit too early or hold back and risk a called strike.

Spin Axis and Break Optimization

deGrom’s curveball typically has a spin axis that tilts toward 12‑6 to 11‑5, meaning it drops almost straight down with a subtle arm‑side tail. In 2020, his average spin axis was around 11:00 on the clock (with 12:00 being pure over‑the‑top vertical break). This tilt, combined with high spin efficiency (over 95%), produces a pitch that dives hard at the bottom of the zone and can be thrown in or out of the strike zone. He and the Mets’ analysts worked to keep that tilt consistent regardless of grip variations; any deviation would give hitters a clue. By pairing his curveball’s spin axis with his fastball’s (which tilts to about 1:30), deGrom forces batters to process two very different movement profiles that start from the same release point.

Release Point Consistency

One of deGrom’s most underrated talents is his ability to replicate his release point across all pitches. By 2018, the horizontal and vertical release points for his fastball and curveball were within 0.5 inches of each other. That extreme consistency means a hitter’s first glimpse of the pitch—the initial 20 feet—gives no sign of what’s coming. Only after the ball has traveled 30–40 feet does the curveball’s downward break become apparent. This delayed recognition is why even elite hitters have trouble squaring up the pitch; they either start their swing too early and miss under it, or they hold up too late and take a called strike. In 2020, deGrom’s curveball produced a whiff rate of 48.6%, the highest among all pitchers who threw at least 100 curveballs, and his called‑strike rate on curveballs in the zone was over 70%.

Strategic Deployment: How the Curveball Makes the Rest of the Arsenal Better

deGrom’s curveball is not thrown simply to change speeds; it is a tactical weapon deployed with specific intent based on batter handedness, count, and game situation. Its role has evolved from a situational get‑me‑over pitch to a primary strikeout weapon that magnifies the effectiveness of his fastball and slider.

Breaking Hitter Timing and Pattern Recognition

The velocity differential between deGrom’s 98–100 mph four‑seam fastball and his 82–84 mph curveball—a gap of roughly 16 mph—alone creates enormous timing disruption. But deGrom goes further: he will throw back‑to‑back curveballs, or a curveball after a slider, to prevent batters from establishing any rhythm. In at‑bats where he throws a first‑pitch curveball, his strikeout rate jumps to over 35%, compared to about 28% when he starts with a fastball. The pitch is equally effective when thrown in the zone for strikes or just out of the zone to induce chase. Left‑handed batters are especially vulnerable, as the curveball breaks away from them; their whiff rate against deGrom’s curveball from 2018–2021 was over 50%. He attacks them with the pitch as a chase offering low and away, knowing they struggle to lay off the hard, late break.

Complementing Fastball and Slider

Perhaps the most important strategic role of deGrom’s curveball is how it elevates his other pitches. The fastball sets up the curveball, and the curveball makes the fastball look faster. Additionally, his slider (89–91 mph) and curveball create a high‑low, left‑right conundrum. When a batter is looking for a slider low and away, deGrom can drop a curveball that tunnels similarly but breaks more vertically. According to Baseball Savant, in 2020, deGrom’s curveball had a run value of -7 (saving seven runs compared to an average pitch), placing him in the 98th percentile among starters. That same year, his fastball and slider also had elite run values, showing how the curveball made the entire repertoire more deadly. The Fangraphs pitch value leaderboards further show that from 2018–2020, deGrom’s curveball ranked among the top three in value per 100 pitches among starting pitchers.

Impact on Career Milestones and Legacy

Jacob deGrom’s curveball has been a cornerstone of his two Cy Young Award‑winning seasons (2018, 2019) and his historically dominant 2020 campaign. In 2018, his curveball was thrown 18.5% of the time, yielding a .190 batting average against and a 36.7% whiff rate. He struck out 269 batters in 217 innings with a 1.70 ERA. The next year, usage jumped to 22.3%, and the pitch produced a staggering 46.4% whiff rate—the highest of his career to that point, and 62 of his 255 strikeouts came on the curveball. In 2020, despite pitching through latissimus dorsi tightness, deGrom posted a 2.38 ERA and a 14.1 strikeouts‑per‑nine‑innings rate. The curveball accounted for 36 of his 94 strikeouts in 12 starts.

The pitch’s performance even when his fastball velocity dipped—as it did in 2020 and during the 2021 season when he posted a 0.55 ERA before injury—highlights how robust the curveball had become. It was not reliant solely on arm strength but on mechanics, spin, and location. Historical comparisons underline the rarity: only a handful of pitchers in the modern era have combined a high‑90s fastball with a curveball that consistently yields a whiff rate above 45%. Clayton Kershaw’s legendary curveball has a slightly different shape (more horizontal break), while Gerrit Cole’s curveball spins fast but does not generate the same vertical drop. deGrom’s ability to maintain elite curveball metrics even while battling significant injuries further cements his standing. A MLB.com feature from 2023 noted that his curveball spin rate and movement remained elite even after moving to Texas, underscoring the pitch’s enduring effectiveness.

Future Trajectory: Adaptation and Longevity

As deGrom enters his late 30s, his curveball will likely remain a vital component of his success, especially as his fastball velocity inevitably declines. After signing with the Texas Rangers, he has shown a willingness to experiment: reports from spring training in 2023 indicated he was tinkering with two curveball grips—one with more vertical drop (12‑6) and one designed for more horizontal movement (a sweeping curve). This adaptive mindset ensures that even if his arm speed slows slightly, he can still generate weak contact and swings‑and‑misses. Modern Rapsodo data and biomechanical analysis allow him to fine‑tune spin axis and finger pressure on a daily basis, which is particularly valuable as he manages minor tightness and workload.

The curveball is a pitch that historically ages well: it relies more on spin, grip, and release point than on raw arm strength. As long as deGrom maintains his healthy shoulder mechanics and release consistency, there is every reason to believe his curveball will remain elite. It may become his primary weapon as he relies on it more heavily, possibly with an increase in usage from the 20–25% range to over 30% in later years. For younger pitchers, deGrom’s curveball journey serves as a masterclass—proof that persistent refinement, data‑driven adjustments, and strategic integration can transform a mediocre offering into one of the most feared pitches in baseball history.

Conclusion: A Pitch That Defined a Peak

Jacob deGrom’s curveball is a masterpiece of mechanical refinement, data‑driven adjustment, and intelligent deployment. Its evolution from a basic, unreliable offering to a pitch that consistently ranks among the best in baseball reflects the dedication and adaptability of its creator. More than just a strikeout tool, the curveball magnifies the effectiveness of his fastball and slider, providing a three‑pitch arsenal that has produced some of the highest strikeout rates and lowest ERAs in modern history. For fans and analysts, deGrom’s curveball is a case study in how a pitcher can develop a secondary pitch into a primary weapon—and for aspiring pitchers, it is a reminder that talent is only the starting point. Consistent work, a willingness to experiment, and an obsessive focus on mechanical precision separate the good from the all‑time greats. The pitch’s legacy is secure, as is deGrom’s place among the elite arms of the 21st century.