Early Years: The Fastball-Slider Foundation

When Jacob deGrom debuted with the New York Mets on May 15, 2013, he presented a simple but devastating two-pitch mix. His four-seam fastball sat around 94 mph with explosive late life, while his slider hovered in the mid-80s with sharp two-plane break. According to FanGraphs pitch data, deGrom threw his fastball on roughly 70% of his pitches during his first two seasons. This heavy reliance worked because his fastball generated whiff rates above 10% and consistently induced weak contact. The slider, used about 20% of the time, posted a whiff rate near 40% against right-handed hitters. This early pairing made deGrom effective but also predictable—opposing hitters knew they could sit fastball early in counts and adjust for the slider with two strikes.

The 2014 season highlighted both the strengths and limits of this approach. deGrom won the National League Rookie of the Year Award with a 2.69 ERA and 144 strikeouts in 140.1 innings. Yet his strikeout rate (9.2 K/9) was solid rather than elite. Opponents batted .278 against his fastball when he threw it in the zone, suggesting that a one-pitch-dominant approach had an inherent ceiling. The blazing velocity created early success, but savvy hitters began timing his fastball more effectively as they saw him multiple times. This early phase set the stage for the most consequential shift in deGrom’s career: the slow, deliberate expansion of his repertoire.

The Addition of the Changeup: A Game-Changing Third Pitch

In 2015, deGrom began incorporating a changeup more frequently, though it took time for the pitch to develop. Early in his career, the changeup was used less than 5% of the time and lacked consistency. By 2016, usage had climbed to roughly 12%, and the results were immediate. The changeup gave deGrom a weapon against left-handed hitters that his slider never provided. Against lefties, a slider away often backs up or stays flat, but a changeup with arm-side fade creates an opposite look. Statcast data from 2016 shows deGrom’s changeup generated a whiff rate over 42%, making it one of the most effective changeups in baseball that season.

The changeup’s development coincided with a noticeable improvement in deGrom’s strikeout numbers. His K/9 jumped from 9.2 in 2014 to 11.2 in 2016, then to 11.3 in 2017. More importantly, his walk rate remained under 2.5 per nine innings, indicating that the new pitch did not compromise his command. The changeup also reduced opponent batting average against left-handed hitters from .240 in 2014 to .195 in 2016. This evolution demonstrates a key principle: adding a quality third pitch doesn't just improve a pitcher’s ability to get strikeouts—it forces hitters to account for another dimension, making the fastball and slider more effective by association.

By the end of 2016, deGrom’s pitch mix had shifted to approximately 58% fastball, 22% slider, 16% changeup, and 4% curveball. The curveball was still a seldom-used fifth option, but its occasional appearance kept hitters honest. The real story was the changeup’s rise from a show-me pitch to a legitimate put-away offering. This period represents the first major structural change in deGrom’s arsenal, and it’s no coincidence that it came immediately before his peak Cy Young run.

Refinement of the Curveball and Four-Pitch Arsenal

Between 2017 and 2019, deGrom transformed from a three-pitch pitcher into a four-pitch maestro. The curveball, which he threw only 4-5% of the time early in his career, saw usage climb to 12-14% by 2018. This wasn’t a new pitch—deGrom had always had a curveball in his back pocket—but it became a weapon he trusted in crucial counts. According to MLB.com analysis, deGrom’s curveball in 2018 averaged 82 mph with over 2,600 rpm of spin, placing it among the highest-spin curves in the game. The pitch generated a whiff rate above 45% and limited opponents to a .147 batting average.

The expansion to a four-pitch mix had a compounding effect. With a fastball at 97 mph, a slider at 90 mph with late bite, a changeup at 89 mph with fade, and a curveball at 82 mph with depth, deGrom now owned four distinct velocity bands. Hitters could no longer simply tee off on the fastball because they had to respect the changeup and curveball in different zones. This diversity allowed deGrom to manipulate at-bats more effectively, especially against elite hitters who might otherwise adjust to a two-pitch plan.

In 2018, deGrom posted a 1.70 ERA with 269 strikeouts in 217 innings, winning his first Cy Young Award. His pitch mix that season was roughly 49% fastball, 22% slider, 20% changeup, and 9% curveball. The fastball usage had dropped significantly from his rookie year, but the quality remained elite. The data suggests that deGrom’s fastball actually became more effective as he threw it less, because hitters could no longer predict when it would come. This phenomenon—where reducing usage of a primary pitch increases its effectiveness—is well-documented in baseball analytics and was a hallmark of deGrom’s peak years.

2019: The Near-Perfect Season

In 2019, deGrom’s pitch mix stabilized. He threw his fastball 48% of the time, slider 25%, changeup 19%, and curveball 8%. The consistency allowed him to repeat his Cy Young performance with a 2.43 ERA and 255 strikeouts in 204 innings. One subtle change: deGrom began using his fastball and slider almost interchangeably early in counts, making it impossible for hitters to guess fastball. According to Pitcher List breakdowns, deGrom’s first-pitch strike percentage climbed to 70% in 2019, up from 66% the year before. Starting at-bats with strikes from different pitch types gave him control of the count and reduced deep counts that lead to walks.

The 2020s: Velocity Adjustments and Injury Adaptation

The 2020 season brought unprecedented challenges with the shortened schedule. deGrom threw only 68 innings but posted a 2.38 ERA with 104 strikeouts. Notably, his fastball velocity peaked at 99.1 mph average, the highest of his career. Yet his pitch mix remained nearly identical to 2019, suggesting that he had reached an optimal mix. The real disruption came in 2021, when deGrom produced arguably the best half-season in baseball history (1.08 ERA, 14.3 K/9 in 92 innings) before an elbow injury cut his season short.

Injuries forced further adjustments. From 2021 onward, deGrom has missed significant time due to shoulder and elbow issues. In his return to the Texas Rangers in 2023, his fastball velocity dipped to an average of 96.5 mph, down from 99 mph in 2021. This drop altered his approach. deGrom leaned more heavily on his slider (30% usage) and changeup (22%) while reducing fastball usage to about 42%. The curveball remained around 6%. This shift acknowledged that his fastball, while still elite, no longer had the same overpowering quality. By prioritizing secondary offerings, deGrom maintained a high strikeout rate (12.5 K/9) despite the velocity decline.

The Rangers saw a different deGrom in 2024: a pitcher who relied less on pure heat and more on sequencing and location. His fastball usage fell to 40% for the first time in his career, while his slider usage exceeded 32%. According to Baseball-Reference, deGrom’s contact rate against his fastball dropped from 78% in 2021 to 72% in 2024, suggesting that even a reduced-velocity fastball, when used sparingly and placed precisely, can remain a swing-and-miss weapon. This evolution from a power pitcher to a crafty power pitcher illustrates the importance of adapting as physical tools change.

Pitch Mix Changes by Year (2014-2024)

A decade of data reveals clear trends in deGrom’s arsenal:

  • Fastball usage dropped from 70% to 40% over his career, while its average velocity peaked at 99.1 mph in 2020 and later settled around 96.5 mph.
  • Slider usage increased from 20% to 30%, becoming his primary secondary pitch. The slider's horizontal movement increased by 2.5 inches from 2014 to 2024, making it sharper.
  • Changeup usage climbed from 5% to 22%, establishing it as an essential weapon against lefties. Its whiff rate has never fallen below 38% in any season since 2016.
  • Curveball usage peaked at 9% in 2018 and has since settled around 6-7%. Despite lower usage, its spin rate and vertical movement remain elite.
  • Four-seam fastball location shifted up from middle-middle early in his career to the upper third of the zone in recent years. This vertical adjustment—throwing higher in the zone—allowed his slider and changeup to play up by creating a larger vertical contrast.

The data demonstrates a pitcher who not only added new pitches but also refined how he deployed each one. deGrom’s ability to change his approach year over year—sometimes subtly, sometimes drastically—sets him apart from pitchers who peak early and then decline because they cannot adapt.

Why deGrom’s Pitch Mix Evolution Matters

Understanding deGrom’s pitch mix evolution offers lessons that go beyond his personal achievements. His career arc shows that top-tier success requires constant reinvention. The pitcher who won the Rookie of the Year award in 2014 would be a different, and weaker, pitcher in 2024 if he never developed his changeup or curveball. Hitters adjust; a two-pitch pitcher can dominate for a season or two, but longevity demands expansion.

deGrom’s approach also highlights the importance of pitch tunneling. Despite having four pitches, deGrom ensures that they all look identical out of his hand until the last possible moment. His release point has remained almost perfectly consistent across all pitches throughout his career. This consistency, combined with overlapping movement profiles early in the pitch’s flight, creates deception that makes his elite stuff even more effective. According to Sports Info Solutions, deGrom’s four-seam fastball and slider share nearly identical vertical approach angles for the first 20 feet of flight. That means a hitter must decide whether to swing at a pitch that looks like a fastball, only to find it diving toward the dirt as a slider.

Injury-Triggered Adjustments

The injuries that have plagued deGrom since 2021 forced him into his most significant adaptation. Losing velocity often marks the end for many pitchers, but deGrom compensated by elevating his fastball and leaning on his slider. The result: in 2024, he posted a 2.87 ERA with an 11.8 K/9 across 120 innings—elite numbers for any pitcher, let alone one in his late 30s with multiple arm surgeries. This resilience stems directly from the deep, diverse pitch mix he developed in his prime. A pitcher with a two-pitch arsenal and declining velocity would have been much more vulnerable.

Statistical Comparison: deGrom Then vs. Now

A side-by-side comparison of deGrom’s 2014 and 2024 seasons reveals the full scope of his evolution:

  • 2014: 2.69 ERA, 3.53 FIP, 9.2 K/9, 2.2 BB/9, 48.2% GB rate, fastball 91.2% of pitches in the zone, whiff rate vs. fastball 16.3%.
  • 2024: 2.87 ERA, 2.91 FIP, 12.2 K/9, 1.9 BB/9, 44.5% GB rate, fastball 42% of pitches in the zone, whiff rate vs. fastball 26.8%.

The most striking change is the whiff rate on the fastball, which improved by over 10 percentage points despite a 2.5 mph velocity drop. This dramatic improvement is entirely attributable to the changed pitch mix: with less fastball usage and better sequencing, hitters struggle to ambush the fastball as they once did. The same phenomenon appears with the slider, which generated a whiff rate of 38% in 2014 and 48% in 2024, again with a slight velocity drop.

The Future of deGrom’s Pitch Mix

As deGrom enters the twilight of his career, questions remain about how much longer his body can hold up. But his pitch mix evolution suggests he may continue to adapt. Some scouts believe he could eventually rely on an even higher percentage of secondary pitches, pushing his fastball usage below 35% as he ages. Others argue that his elite command of the fastball—even at reduced velocity—will keep it as an effective pitch when used sparingly.

What is clear is that deGrom has set a template for modern pitchers: build a foundation with a plus fastball, add a quality secondary pitch early, then expand the arsenal gradually while always maintaining pitch tunnel and deception. His willingness to change his approach—sometimes mid-career, sometimes mid-season—has allowed him to remain among baseball’s elite even as injuries have taken their toll. The evolution from a raw fastball-slider pitcher to a sophisticated multi-pitch tactician is one of the most instructive arcs in recent baseball history.

For fans and analysts, deGrom’s journey underscores a simple truth: in baseball, as in life, those who adapt survive. The pitcher who threw 70% fastballs in 2014 is now a pitcher who throws 40% fastballs, 30% sliders, 22% changeups, and a sprinkling of curveballs—and he’s better for it. His career is a case study in necessary evolution, and it’s far from over.