Understanding WAR and Its Significance

Wins Above Replacement (WAR) is the most comprehensive single-number metric in baseball, designed to estimate a player’s total contributions in wins relative to a theoretical replacement-level player—essentially a freely available minor leaguer or bench player. For pitchers, WAR combines innings pitched, earned run average (ERA), strikeouts, walks, home runs allowed, fielding-independent pitching, and park/league adjustments into one value. The two most widely used versions—Baseball Reference’s bWAR and Fangraphs’ fWAR—differ slightly in their inputs: bWAR uses runs allowed (actual runs) while fWAR uses FIP (fielding independent pitching). Despite these differences, both systems paint the same picture: Jacob deGrom’s peak seasons belong in the conversation for the greatest ever.

Through 2024, deGrom has accumulated 49.2 career bWAR, placing him 13th among active pitchers. But raw totals undersell his peak. From 2018 to 2021, he posted four of the top 25 single-season WAR marks by a pitcher this century. His ability to combine extreme strikeout rates (often above 11 K/9) with elite walk rates (below 2.0 BB/9) created a rare efficiency that WAR captures beautifully. By examining his highest-WAR campaigns, we can identify precisely why deGrom stood apart from even the best arms of his generation.

deGrom’s Top WAR Seasons

2018: The Breakout Year (bWAR: 8.8; fWAR: 8.9)

Jacob deGrom’s 2018 season is the gold standard of his career. He posted a 1.70 ERA over 217 innings, striking out 269 batters while walking just 46—a K/BB ratio of 5.85. His 8.8 bWAR was the highest by any National League pitcher since Clayton Kershaw’s 8.8 in 2014 and the best by a Mets pitcher since Dwight Gooden’s 12.2 in 1985. What made the season transcendent was a combination of dominance and futility: deGrom’s run support averaged a mere 3.5 runs per game, and the Mets scored two or fewer runs in 14 of his 32 starts. He went 10-9, the lowest win total for a Cy Young winner in a non-shortened season.

Digging deeper, his fastball averaged 96 mph and touched 99 with late life, but his slider was the true weapon. Opponents hit .153 against the slider and whiffed on nearly 48% of swings, generating an absurd 39.6% called-strike-plus-whiff rate. He allowed just 10 home runs all year (0.41 HR/9), second best in the NL. His WHIP of 0.915 led the majors and was the lowest by a qualifying pitcher since Pedro Martínez in 2000 (0.737). According to Baseball Savant, deGrom’s expected weighted on-base average (xwOBA) was .234, ranking in the 99th percentile. The 8.8 WAR ranks 15th all-time among single-season marks by a pitcher since 1901, tying him with Randy Johnson’s 1995 and ahead of Roger Clemens’ best.

2019: Continued Excellence (bWAR: 7.2; fWAR: 7.5)

Back-to-back Cy Young Awards cemented that 2018 was no fluke. In 2019, deGrom posted a 2.43 ERA across 204 innings with 255 strikeouts and 44 walks. His WHIP of 0.971 again led the majors, and his K/9 rose to 11.3 from 11.2 the year before. The subtle improvement came from his changeup. He increased its usage from 11% to 14%, and hitters managed just a .202 average and .299 slugging percentage against it. This third pitch kept opponents from keying on his fastball and slider, elevating his overall effectiveness even as the leaguewide home run spike surged—he allowed 18 homers, up from 10.

Only two NL pitchers have ever posted back-to-back seasons with at least 7.0 WAR and a sub-2.50 ERA: Jacob deGrom and Sandy Koufax (1965-1966). deGrom’s 2019 campaign also featured a 1.86 FIP from May onward, as he found another gear midseason. His 7.2 bWAR ranked second in the NL among pitchers, trailing only Jacob deGrom’s own 2018 mark—a testament to his consistency. Fangraphs credited him with 7.5 fWAR, noting his FIP of 2.67 was actually higher than his ERA, suggesting even better peripherals.

2020: Short but Stellar (bWAR: 4.9; fWAR: 4.3 in 68 IP)

The pandemic-shortened 2020 season saw deGrom produce a 4.9 bWAR in just 68 innings over 11 starts. That equates to a 162-game pace of roughly 11.6 WAR—a level never reached in a full season. His 2.38 ERA, 104 strikeouts, and 0.956 WHIP were exceptional, but the underlying metrics are even more staggering. His strikeout-to-walk ratio of 8.7 was the best in baseball, and his FIP of 1.94 indicated he was even better than his ERA. His fastball averaged 98.5 mph, the hardest among all starters, and his slider generated a 56% whiff rate—one of the highest ever recorded for any single pitch type.

In one memorable start against the Phillies in August, deGrom struck out 14 over eight innings of one-run ball, throwing 97 pitches. He had four starts with at least 12 strikeouts and zero starts with fewer than seven. The 4.9 WAR in 11 starts translates to the highest per-inning rate of any pitcher in major league history for a season of at least 60 innings. While the small sample size invites skepticism, it also reinforces that deGrom was capable of historical dominance even under unprecedented circumstances.

2021: A Peak Cut Short (bWAR: 7.2; fWAR: 7.0 in 92 IP)

Though not originally in the list, the 2021 season demands inclusion because deGrom reached a 7.2 bWAR in only 92 innings (15 starts) before an elbow injury ended his season. He posted a 1.08 ERA, 146 strikeouts, 11 walks, and a 0.554 WHIP—numbers so absurd they looked like a video game set on rookie. His FIP was 1.23, and his strikeout rate of 14.3 K/9 was the highest ever for a single season (minimum 90 innings). The 7.2 bWAR tied his 2019 total but in half the innings, meaning he produced 0.078 WAR per inning, the highest single-season rate in history.

Breaking down the dominance: deGrom allowed two or fewer runs in every start. He struck out at least 10 in eight of his 15 starts, including a 15-strikeout game against the Nationals on June 16. His fastball sat at 99 mph, touching 102, and his slider held hitters to a .116 batting average. The question of “what if he had stayed healthy” looms large over his legacy—a full 30-start season at that pace would have produced roughly 14.4 WAR, shattering the modern single-season record of 11.7 set by Pedro Martínez in 2000.

The Factors Behind His Dominance

Elite Pitch Arsenal

deGrom’s success is built on a four-pitch mix, all of which play off a fastball with elite velocity and unusual movement. His four-seam fastball averages 98–99 mph with a vertical approach angle (VAA) that makes it appear to rise as it reaches the plate. Hitters consistently swing under it, leading to a whiff rate around 25% in his peak years. His slider is a wipeout pitch: thrown at 89 mph with two-plane break, it generated whiff rates above 50% from 2018–2021. The changeup, thrown at 88–89 mph with heavy arm-side fade, holds left-handed hitters to a .200 batting average. His curveball, used roughly 8% of the time, adds a different vertical look that keeps hitters from timing his release point.

According to Baseball Savant, deGrom ranked in the 99th percentile or better in run value, whiff rate, and expected weighted on-base average from 2018 to 2021. No other pitcher during that span dominated with so many distinct offerings at such high efficiencies. His ability to elevate his fastball to the top of the zone and bury his slider below the zone made his strike zone one of the most difficult to cover in history.

Unmatched Control and Command

Elite control (limiting walks) combined with elite command (placing pitches exactly where intended) separates deGrom from flamethrowers who rely solely on velocity. From 2018 to 2020, his walk rate stood at 2.0 BB/9, while the league average hovered around 3.0. In 2021, he walked just 11 batters in 92 innings—an absurd 1.1 BB/9, the lowest among all qualified pitchers since 1919 (minimum 90 innings). This precision allowed him to expand the strike zone with breaking pitches while using his fastball to paint the corners.

His sequencing also sets him apart. deGrom rarely falls into predictable patterns; he mixes fastballs early in counts to get ahead, then expands with sliders and changeups once he has two strikes. The result is a pitcher who can generate swings and misses without sacrificing efficiency. In 2018, he threw 65.2% first-pitch strikes, ranking among league leaders. That combination of overpowering stuff plus surgical precision is the hallmark of his best seasons.

Mental Fortitude and Adversity

deGrom’s peak seasons coincided with periods of extraordinary adversity. In 2018, the Mets offense ranked 12th in the NL in runs scored while deGrom was on the mound, yet he never pressed. He maintained a stoic demeanor, refusing to let a lack of run support affect his execution. In 2020, he navigated the pandemic’s disrupted schedule and the mental toll of playing in empty ballparks. In 2021, despite four straight rainouts that broke his routine, he returned to strike out 15 over seven innings in a July start against the Braves.

This mental toughness is a critical but often overlooked component of WAR—the metric doesn’t measure attitude, but results. deGrom’s ability to compartmentalize allowed him to throw strikes consistently, even when the team behind him was struggling. His best seasons saw him lead the league in quality start percentage and avoid the multi-inning blowups that plague less focused pitchers.

Historical Comparisons

To appreciate deGrom’s best seasons in context, we can compare his peak WAR totals to other legendary pitchers. Since 2000, the highest single-season bWAR marks are:

  • Pedro Martínez (2000): 11.7 bWAR in 217 innings – the gold standard, with a 1.74 ERA, 284 strikeouts, and 0.737 WHIP.
  • Randy Johnson (2001): 9.9 bWAR in 249.2 innings – a 2.49 ERA with 372 strikeouts.
  • Jacob deGrom (2018): 8.8 bWAR in 217 innings – the highest in the NL since 1997.
  • Justin Verlander (2011): 8.4 bWAR in 251 innings – Cy Young and MVP season.
  • Clayton Kershaw (2014): 8.0 bWAR in 198.1 innings – a 1.77 ERA and 239 strikeouts.

deGrom’s 8.8 WAR ranks sixth among all pitchers since 2000, trailing only Martínez (twice), Johnson, Clemens, and Verlander. If we adjust for innings, deGrom’s 2021 pace (7.2 in 92 innings) would equate to about 12.6 WAR over a full 200-inning season—surpassing Pedro’s mythical 2000 season. The Fangraphs WAR leaderboard confirms that only Martínez, Johnson, and Verlander have exceeded deGrom’s peak in the last two decades using fWAR as well.

What separates deGrom from his peers is not just the height of his peaks but the consistency of his underlying skills. His walk rate, whiff rate, and hard-hit rate in his best seasons all rank among the top 10 in MLB history. Even when his ERA rose slightly, his FIP stayed elite, suggesting sustainable dominance rather than luck.

Legacy and Future Outlook

Jacob deGrom’s career has been defined by injury as much as dominance. After 2021, he missed most of 2022 and 2023 due to a stress reaction in his right scapula, a forearm strain, and eventually Tommy John surgery (his second, having had it in 2010 as a minor leaguer). In 2024 with the Texas Rangers, he returned for 18 starts, posting a 3.40 ERA and 4.1 bWAR in 85 innings—a solid season but a far cry from his peak. His fastball still averaged 97.5 mph, and his strikeout rate was 11.2 K/9, but command wavered (3.3 BB/9), and he missed time with groin and hamstring issues.

At 36 years old, the question is whether deGrom can recapture the magic of 2018–2021 for one more run. Historically, pitchers who rely on extreme velocity often fade in their mid-30s. deGrom has already beaten those odds in maintaining raw stuff, but durability remains the enemy. If he can make 28–30 starts in 2025, even with a slightly higher ERA (3.00–3.50), he could add a third Cy Young to his resume and push his career WAR past 55, strengthening his Hall of Fame case.

His peak seasons (2018, 2019, 2020 short, and 2021 truncated) collectively represent a stretch of pitching excellence that rivals any in baseball history. The WAR numbers back it up: from 2018 to 2021, deGrom accumulated 28.1 bWAR across just 75 starts and 581 innings. No other pitcher in that span reached even 20 WAR in so few appearances. For more on his career totals and advanced stats, Baseball Reference provides comprehensive data, and MLB.com’s official player page tracks his ongoing journey with the Rangers.

Conclusion

Jacob deGrom’s best seasons by WAR—2018 (8.8), 2019 (7.2), 2020 (4.9 in short season), and 2021 (7.2 in 92 innings)—showcase a pitcher operating at a level few have ever reached. His combination of elite velocity, command, and pitch diversity allowed him to generate swings and misses while limiting walks and hard contact. Factors such as his evolving arsenal, mental toughness, and ability to perform in adverse circumstances set these seasons apart. His 2018 campaign remains one of the most dominant in the modern era, and his 2021 half-season is arguably the most brilliant half-season ever thrown. As he continues his journey with the Texas Rangers, deGrom’s WAR peaks will stand as benchmarks for future generations, a reminder of what happens when overpowering stuff meets surgical precision.