Few pitchers in Major League Baseball history have combined raw power and precision as effortlessly as Jacob deGrom. Over his career with the New York Mets, deGrom posted strikeout numbers that not only dwarfed league averages but also placed him in the same conversation as the most dominant arms to ever take the mound. By breaking down his strikeout ratios and comparing them to MLB norms, we can see why deGrom is considered a generational talent. His ability to miss bats at an elite rate, year after year, sets him apart even in an era of rising strikeouts. This deep dive examines the metrics that define his dominance—K/9, strikeout percentage, whiff rate, and strikeout-to-walk ratio—and puts them in context with both contemporary peers and all-time greats.

The Rise of a Strikeout Machine

Jacob deGrom debuted in 2014 as a relatively unheralded 26-year-old rookie. Initially relying on a mid-90s fastball and a sharp slider, he quickly established himself as a strikeout pitcher. His strikeout rate per nine innings (K/9) climbed steadily from 9.2 in 2015 to a career-best 13.8 in 2022, when he was limited to just 11 starts due to injury. Even in that small sample, his ability to miss bats was historically elite.

deGrom’s rise coincides with a broader trend in baseball: strikeout rates have been climbing league-wide for two decades. However, deGrom consistently outperformed the league average by a wide margin. In 2018, the first of his two Cy Young Award seasons, deGrom struck out 269 batters in 217 innings, good for an 11.2 K/9 against an MLB average of 8.6. That season, only Chris Sale and Max Scherzer had a higher K/9 among qualified starters. But unlike those two, deGrom did it with a delivery that seemed almost effortless, generating massive velocity and movement without sacrificing control.

His emergence as a strikeout artist was not immediate. In his rookie year, deGrom posted a 8.0 K/9—respectable but not elite. The turning point came in 2015, when he began to rely more heavily on his slider and developed a feel for elevating his fastball. By 2017, his K/9 had jumped to 10.2, and he never looked back. What makes his rise so impressive is that he became better at missing bats even as the league caught on to his arsenal.

K/9: The Standard Rate

The most commonly cited strikeout metric is K/9, or strikeouts per nine innings. deGrom’s career K/9 stands at 11.0 through 2023, while the MLB average for starting pitchers over the same period is approximately 8.3. That nearly three-strikeout gap per nine innings is massive—deGrom effectively added an extra third of a strikeout per inning compared to the typical starter.

It is worth noting that K/9 can be influenced by factors such as park dimensions, opponent quality, and umpire strike zones. Yet deGrom’s dominance holds up even when adjusting for these variables. In each season from 2015 to 2022, his K/9 never fell below 9.0, and in four of those seasons it exceeded 11.0. By contrast, the league average for starting pitchers during that span never rose above 8.9.

Digging deeper, deGrom’s K/9 numbers become even more impressive when looking at his peak years (2018–2022). During that five-season stretch, he averaged a 12.0 K/9, while the league averaged 8.7. That 3.3 difference is the largest gap between any qualified pitcher and the league average over a multi-year period since the steroid era ended. Only a handful of pitchers in history have sustained such a differential—names like Randy Johnson, Pedro Martinez, and Nolan Ryan. For a player who didn’t debut until age 26, that level of dominance is staggering.

“When you watch deGrom pitch, you see a guy who can throw a 99 mph fastball up in the zone and then drop a 93 mph slider that looks like a fastball until it’s too late. That combination is almost unfair.” — MLB scout, quoted in The Athletic

Even in his injury-shortened 2022 campaign, deGrom’s 13.8 K/9 was more than five strikeouts per nine innings higher than the league average of 8.6. That gap is almost unprecedented in the modern era. It’s not just that deGrom is good—it’s that he is operating on a completely different plane from his peers.

Strikeout Percentage (K%)

While K/9 is useful, sabermetricians prefer strikeout percentage (K%), which measures strikeouts as a percentage of total batters faced. This statistic is less influenced by walks and batters hit by pitch, offering a cleaner view of a pitcher’s ability to miss bats.

deGrom’s career K% is 32.5%, meaning nearly one in three batters he faces ends up walking back to the dugout after a strikeout. The MLB average for starting pitchers during his career is about 22.5%. That 10-percentage-point gap is enormous. For context, a 10% difference in K% between two pitchers translates to roughly 25–30 extra strikeouts per 200 innings. Over a full season of 200 innings, that gap is the difference between a good strikeout pitcher (say, 180 Ks) and an elite one (220+ Ks).

In his prime, deGrom posted K% numbers that peaked at 38.9% in 2022 and 36.5% in 2020. No other qualified starting pitcher in the last 50 years has sustained a K% over 35% across multiple seasons except for a select few like Randy Johnson, Pedro Martinez, and Clayton Kershaw at their peak. deGrom belongs in that pantheon of swing-and-miss artists. What’s more, his K% didn’t just spike in a few games—it was consistent month after month. In 2019, for example, his K% was 33.8%; in 2020, 36.5%; in 2021, 34.5%; and in 2022, 38.9%. That kind of sustained dominance is unheard of in the modern game.

The key to deGrom’s high K% is his ability to get strikeouts in two-strike counts. He leads the league in called strike three rate and swing-and-miss on pitches outside the zone. When he has a batter 0-2 or 1-2, he attacks with pitches that are almost impossible to hit. According to Baseball Savant, deGrom’s put-away percentage—the rate at which he finishes off a batter after two strikes—has often exceeded 25%, while the MLB average is around 18%. That extra edge is what pushes his K% into historic territory.

Whiff Rate and Swing-and-Miss Ability

Another key insight into deGrom’s strikeout dominance is his whiff rate—the percentage of swings that miss the ball. deGrom’s whiff rate on all pitches (including swings outside the zone) has consistently ranked among the league’s elite. In 2020, for example, his whiff rate of 38.4% was the highest among starters with at least 50 innings, according to FanGraphs. That means nearly two out of every five swings against him resulted in a miss.

The secret lies in his repertoire. deGrom throws a four-seam fastball that averages 98–99 mph and rides up in the zone, producing a whiff rate above 30%. He complements it with a slider that has elite vertical and horizontal break, generating whiff rates near 50%. When batters can’t catch up to the fastball and can’t lay off the slider, the result is a strikeout—or weak contact that keeps runners off base. The combination of pitch movement and deception is what makes deGrom so difficult to square up.

Furthermore, deGrom’s changeup, though used less frequently, has been devastating against left-handed hitters, with a whiff rate of over 40% in 2021. That third pitch prevents batters from timing his fastball, making his strikeout arsenal even more dynamic. In 2021, he threw his changeup about 15% of the time against lefties, and they managed a .179 batting average and a 43% whiff rate. The pitch nearly mirrors his fastball arm speed but drops off the table, leaving hitters lunging.

Whiff rate is a direct indicator of a pitcher’s stuff, and deGrom’s is among the best ever recorded. Among pitchers with at least 500 batters faced since 2015, only two have a higher whiff rate than deGrom: Aroldis Chapman and Josh Hader—both relievers who face hitters only once. Among starters, deGrom is the clear leader. His ability to generate swinging strikes in the zone and out of it makes him a nightmare for opposing hitters.

Strikeout-to-Walk Ratio (K/BB)

Strikeouts alone don’t tell the full story; a pitcher’s control is equally important. deGrom’s strikeout-to-walk ratio (K/BB) is among the best in modern history, especially during his Cy Young seasons. In 2018, he posted an 8.9 K/BB ratio—far above the league average of 3.2. That means deGrom struck out nearly nine batters for every one he walked. Such dominance with command is rare; most power pitchers struggle with walks, but deGrom has elite control to go with his elite stuff.

In 2021, deGrom’s K/BB peaked at 10.3, albeit in a shortened season due to injuries. To put that in perspective, the league average for starting pitchers that year was 3.0. A ratio above 5 is considered excellent; above 8 is elite. deGrom’s career K/BB stands at 5.6, while the average starter over his career has a ratio near 2.8. This combination of high strikeouts and low walks is what makes deGrom so difficult to score against. He doesn’t beat himself, and he rarely gives free passes that can turn into big innings.

One reason for his low walk rate is his ability to throw strikes with all three pitches. deGrom’s zone rate—the percentage of pitches thrown in the strike zone—has consistently been above 45%, while the league average for starters is around 44%. That might not seem like a big difference, but when you consider that his pitches are already very hard to hit, throwing them in the zone makes him almost unhittable. Batters know that if they don’t swing, they risk being called out on strikes; if they do swing, they risk missing and striking out.

Comparison to MLB Averages

Here is a quick snapshot of deGrom’s career strikeout metrics compared to the average MLB starting pitcher (2014–2023):

  • deGrom K/9: 11.0
  • MLB average K/9: 8.3
  • deGrom K%: 32.5%
  • MLB average K%: 22.5%
  • deGrom K/BB: 5.6
  • MLB average K/BB: 2.8
  • deGrom whiff rate: ~30% (peak years above 35%)
  • MLB average whiff rate: ~24%

These numbers illustrate a pitcher who operates in a different realm from his contemporaries. When healthy, deGrom doesn’t just outperform the average—he redefines what is possible on the mound. The gap between him and the typical starter is wider than the gap between that starter and a replacement-level pitcher. That’s the mark of a legend.

Historical Context: deGrom vs. All-Time Greats

To truly appreciate deGrom’s strikeout ratios, we must compare them to the all-time greats. Pedro Martinez posted a career K/9 of 10.0, Randy Johnson 10.6, and Nolan Ryan 9.5. deGrom’s 11.0 career K/9 is above all of them. Among pitchers with at least 1,500 innings, only Chris Sale (11.0) matches deGrom, while Max Scherzer (10.8) is close but behind. According to Baseball Reference, deGrom’s career K/9 ranks third all-time among starting pitchers with at least 1,000 innings, behind only Sale and Scherzer—and he is essentially tied with Sale.

In terms of K%, deGrom’s 32.5% is the highest in MLB history among starting pitchers with at least 1,000 innings, surpassing Sale (31.2%) and Scherzer (30.0%). This stat alone places him above Hall of Famers like Bob Gibson (25.2%) and Sandy Koufax (25.5%), though eras were different. deGrom’s dominance is not just a product of the modern high-strikeout era; he leads even his own contemporaries. When you adjust for league average, deGrom’s K%+ (which standardizes strikeout rate to league and park) is among the best ever—even better than peak Pedro or Randy Johnson.

But perhaps the most telling comparison is with the pitcher who many consider the most dominant of all time: Pedro Martinez. In his prime (1997–2003), Martinez had a K/9 of 10.8 and a K% of 31.5%. deGrom’s peak (2018–2022) saw him at 12.0 K/9 and 35.6 K%. While Martinez had the advantage of pitching in the height of the steroid era, deGrom’s numbers are still remarkable. The difference is that Martinez maintained his dominance for a longer period; deGrom’s career has been interrupted by injuries. But in terms of pure strikeout rate per inning, deGrom stands alone.

“Jacob deGrom has the best stuff I’ve ever seen from a starting pitcher. The combination of velocity, movement, and command is unlike anything this generation has witnessed. He’s the closest thing to Pedro Martinez I’ve ever seen.” — Hall of Famer John Smoltz, during a 2021 broadcast

Impact on ERA and Value

Strikeout ratios directly influence a pitcher’s run prevention. deGrom’s career ERA of 2.52 is lower than his peers, and his FIP (Fielding Independent Pitching) is even better at 2.48. FIP focuses on outcomes a pitcher can control: strikeouts, walks, and home runs. deGrom’s elite strikeout numbers, combined with low walk rates, give him a FIP that is consistently among the league’s best. In fact, from 2018 to 2021, his FIP was below 2.00 in each season—a feat achieved only by a handful of pitchers in history.

In 2018, deGrom’s ERA of 1.70 was supported by a 1.99 FIP. That season, he had a 36.5% K% and a 3.9% walk rate. The Mets scored just 3.5 runs per game that year, but deGrom’s strikeout ability kept him in games. He won the Cy Young award despite a win-loss record of 10-9, a testament to how valuable strikeouts are in preventing runs. Without those strikeouts, his ERA would have been much higher, and the Mets would have lost even more games.

Wins Above Replacement (WAR) also rewards strikeout-heavy performances. deGrom’s 9.4 bWAR in 2018 is the highest by a starting pitcher in the 21st century, matching peaks of Pedro Martinez and Randy Johnson. That season, his strikeout contributions alone accounted for roughly 40% of his total value, according to MLB.com’s WAR explanation. It’s no exaggeration to say that deGrom’s strikeout ratios are the engine behind his run prevention and his overall value to his team.

Injury Concerns and Recent Performance

No discussion of deGrom’s strikeout ratios is complete without acknowledging his recent injury history. Since 2021, deGrom has been sidelined by forearm and shoulder issues, then underwent Tommy John surgery in 2023. When he has pitched, his strikeout numbers have remained elite—13.8 K/9 in 2022—but the sample sizes have been small (26 innings in 2023, 64 in 2022). The question for the remainder of his career is whether he can sustain those ratios while staying on the mound.

The league average K/9 for 2023 was 8.6, so even a diminished version of deGrom would still be well above average. But replicating his 12+ K/9 peaks may be difficult as he ages and recovers from surgery. The velocity and movement that made him unhittable could decline slightly, which might lower his whiff rates. However, deGrom has always had exceptional command and pitchability, which could help him remain effective even if his stuff regresses.

Another factor is his recovery timeline. deGrom is expected to return in mid-2024 or 2025 with the Texas Rangers, his new team. If he can stay healthy, he could still post elite strikeout numbers. Even a 10.5 K/9 and 28% K% would be excellent—well above league average. The key is whether his body can handle the workload. His mechanics have been described as violent, which may contribute to his injuries. Nevertheless, his strikeout ratios from 2014–2022 are locked in as one of the best stretches in baseball history.

Conclusion: A Legacy of Dominance

Jacob deGrom’s strikeout ratios—K/9, K%, K/BB, and whiff rate—are among the best ever recorded. Compared to MLB averages, they reveal a pitcher who consistently operated at a level 30–50% better than the typical starter. His ability to miss bats, combined with pinpoint control, made him the most feared pitcher in the game for a half-decade. When he was healthy, batters knew they were facing a pitcher who could dominate them with pure stuff and precision.

While injuries have limited his innings, the numbers he produced are indelible. For fans and analysts, deGrom’s strikeout ratios serve as a benchmark for future generations. They also remind us that, at his best, Jacob deGrom was not just an All-Star or a Cy Young winner—he was a strikeout artist in the truest sense. His 2018 and 2019 seasons, in particular, will be remembered as some of the most dominant campaigns by a pitcher in the modern era.

To explore more of deGrom’s career splits, check his Baseball Reference page and FanGraphs profile. For a deeper dive into strikeout trends across MLB, MLB.com’s strikeout rate glossary is a helpful resource. And for those interested in deGrom’s pitch movement, Statcast data is available at Baseball Savant. These tools allow fans to appreciate just how exceptional his strikeout ratios truly are.