Top 20 Relief Pitchers for the 2025 MLB Season

The 2024 season showed us a lot, but one of the key storylines that stood out was the impact that high-caliber relief pitchers had on their teams’ success.

The Cleveland Guardians were the prime example of this, as they sported a three-headed monster with Emmanuel Clase, Cade Smith and Hunter Gaddis in the backend on route to a top-ranked bullpen across the board that guided them to an ALCS appearance.

Then the Dodgers and the Yankees were led by the likes of Blake Treinen and Luke Weaver, and they rode their bullpen’s momentum all the way to the World Series.

While relief pitching may be a volatile position, there are plenty of arms that have displayed a remarkable amount of skill to ensure the position remains a hot-bed of talent year after year, despite the higher rate of turnover than any other position in baseball.

With all that said, let’s dive into the top relievers for the 2025 season.

Honorable Mentions:

Jeff Hoffman (TOR)
A.J. Puk (ARI)
Jeremiah Estrada (SD)
Michael Kopech (LAD)
Lucas Erceg (KC)
Orion Kerkering (PHI)

The honorable mentions list for relief pitching is as star-studded as any, with the likes of All-Stars, postseason closers and some of the better young talent the game has to offer.

Jeff Hoffman is the first name on this list, fresh of his first-career All-Star appearance after posting a 2.17 ERA, 2.52 FIP, 0.96 WHIP and .195 AVG against. He’s an elite strikeout arm ranking in the 96th percentile in K-rate, whiff rate and chase rate, according to Baseball Savant.

However, Hoffman struggles when it comes to the quality of contact he surrenders. In 2024, his hard-hit rate fell in the 21st percentile, his barrel rate the 48th percentile and he only kept balls on the ground at a 22nd-percentile rate.

A.J. Puk looked like a new man after being acquired mid-season by the Arizona Diamondbacks. In 27.1 innings in the desert, he posted a 1.32 ERA, 1.63 FIP, 0.73 WHIP, .155 AVG against, 41.7% K-rate and 4.9% walk rate.

However, he was a mid-4.00s ERA arm in Miami prior to the deal and has never been better than 3.12 ERA in his five-year MLB career. A small sample size of elite performance is what holds him off this list.

Few arms in baseball struck hitters out that rate Jeremiah Estrada did in 2024, as he ranked in the 99th percentile of league arms in K-rate.

The issue with Estrada is the fact there’s not much to go off of other than this season, as he has just 16.1 innings under his belt in the two seasons prior to last combined, both of which were uninspiring. Another season like the one he just had would put him in a better spot to crack the 2026 rendition of this list.

Michael Kopech found new life with the World Champion Los Angeles Dodgers after the trade deadline. Here he would post a 1.13 ERA, 2.54 FIP, 0.79 WHIP, .115 AVG against and a 33.0% K%.

This past year though was Kopech’s first season back in a relief role after two underwhelming seasons in 2022 and 2023 in the White Sox’s rotation. We also have to keep in mind that prior to the trade he was a high-4.00 ERA guy in Chicago, so in order to make a better case to crack the Top 20, he’ll need to show that the Dodgers version of him is sustainable.

Before being dealt to Kansas City, Lucas Erceg was a strong right-hand man to Mason Miller in Oakland. After the trade though, Erceg finally got his shot as closer with the Royals and ran with it, posting a 2.88 ERA, 1.17 FIP, 0.84 WHIP, .191 AVG against and 11.16 K/9 with 11 saves.

Sample size is once again the issue here, as 2024 as a whole was a breakout year for Erceg. If he can prove he’s the guy in Kansas City as they firmly enter their postseason contention window, it would go a long way to receiving more legitimate Top 20 consideration.

Orion Kerkering put together a very solid campaign for the Phillies in 2024. In 63.0 innings of work, he posted a 2.29 ERA, 2.42 FIP, 1.08 WHIP, .220 AVG against and a 28.8% K%.

It’s a sample size thing for Kerkering as well, as while he showed glimpses of great things in ’23, this past season was the one where he put himself on the map. However, now that Hoffman and Carlos Estévez are out of the picture in Philadelphia, there’s a potential for a higher volume of high-leverage innings for the near 24-year-old to better make his case to be amongst the Top 20 in a year’s time.

20. Hunter Gaddis (Cleveland Guardians)

2024 Stats: 78 G, 74.2 IP, 1.57 ERA, 0.76 WHIP, .165 BAA, 2.82 FIP, 8.0 K/9, 1.7 BB/9

Finkelstein	Morgenstern	Treuden	Appel	Leighton	McMullen
RANK: 24	RANK: 30	RANK: 18	RANK: 20	RANK: 21	RANK: 23

The 2024 season was one of career revitalization for Hunter Gaddis, as his first season as a relief option seemingly went as well as it possibly could have gone.

In 74.2 innings across 78 appearances, the 26-year-old posted a shimmering 1.57 ERA, 0.76 WHIP, .165 AVG against, along with a 92nd percentile 5.0% walk rate.

This was a stark contrast from his 2023 big league campaign when he made 11 appearances, seven of which were starts, and pitched to the tune of 4.50 ERA and 1.31 WHIP.

As much success as Gaddis has found as a reliever, there are a few reasons as to why he ranks at the bottom of this Top 20 list.

He’s not much of a strikeout arm, with just a 55th percentile K-rate (23.7%) and a 45th percentile whiff rate (25.0%), which in the type of higher leverage innings that he threw in last season holds a fair amount of importance.

His hard contact metrics leave a bit to be desired as well, as he fell in just the 68th percentile in hard-hit rate (36.6%) and the 58th percentile in AVG exit velocity (88.5 mph).

Some relievers that give up a fair amount of hard contact and aren’t necessarily strikeout arms can get away with this if they can induce their fair share of groundballs, but at a 22nd percentile clip (37.6%) last season, Gaddis doesn’t do that.

While relief pitching may be extremely volatile and Gaddis has his vulnerabilities over a small sample size, we have to evaluate based on what we’ve seen. In 2024 he showed us little to no reason not to rank him within the Top 20 with the masterclass set-up performance he displayed.

19. Ben Joyce (Los Angeles Angels)

2024 Stats: 31 G, 4 SV, 34.2 IP, 2.08 ERA, 1.15 WHIP, 3.19 FIP, 8.6 K/9, 3.6 BB/9

Finkelstein	Morgenstern	Treuden	Appel	Leighton	McMullen
RANK: 13	RANK: 30	RANK: 20	RANK: 30	RANK: 23	RANK: 11

Ben Joyce might be one of, if not the biggest, freaks of nature on this list, thanks to his incredible fastball.

His 102.1 mph four-seamer (which he threw 45.7% of the time in 2024) caused hitters extreme headaches, as they could only muster a .194 AVG and .268 SLG against it.

This played a significant role in the very impressive 2.08 ERA, 1.15 WHIP and .210 AVG against season he put together with the Angels.

Now the caveat is the control, as Joyce still struggled with giving up free passes with a 9.9% walk-rate, and doesn’t have the strongest strikeout rate to help mitigate that.

It is important to note though his 3.63 BB/9 was the lowest clip he’s had since his stop in Double-A in 2022, meaning further improvement in this area could bump him up next season. At the end of the day though, we have to evaluate what he did on the field, and improvement aside, his walk rate wasn’t great.

And as good as his four-seamer is, his sinker didn’t manage to miss bats very well as hitters managed to get to it for a .286 AVG.

That being said, if you look at his quality of contact metrics as a whole, while he skews more average in hard-hit rate, hitters only barrel his stuff 4.4% of the time and ground out nearly 60% of the time (59.3%).

With how good the fastball is and how he has managed to be solid enough in the quality of contact he gives up, Joyce has the makings of a big-time late-inning reliever that’s built to last, despite his current flaws.

18. Blake Treinen (Los Angeles Dodgers)

2024 Stats: 50 G, 46.2 IP, 1.93 ERA, 0.94 WHIP, 2.99 FIP, 10.8 K/9, 2.1 BB/9

Finkelstein	Morgenstern	Treuden	Appel	Leighton	McMullen
RANK: 19	RANK: 25	RANK: 19	RANK: 9	RANK: 25	RANK: 22

It was a special year for Blake Treinen in 2024, as not only did he win the World Series, but he picked up right where he left off in 2021, after injury-riddled 2022 and 2023 campaigns.

He managed to post yet another sub-2.00 ERA in 2024 (1.93), so if you included the 5.0 innings pitched in 2022, it would be Treinen’s third straight season under that threshold.

In the process of achieving that mark, he also managed to add his third straight season with a sub-1.00 WHIP and sub-.200 AVG against.

He’s truly an arm that has little flaws, as he generates his fair share of strikeouts with a 30.4% K-rate in 2024; he doesn’t walk hitters much with a 6.0% walk rate; and he limits hard contact with a 33.9% hard-hit rate, 5.2% barrel rate and 87.6 mph AVG exit velocity.

He might also have one of the most lethal pitches in all of baseball in his sweeper. Last season opponents managed to hit just .120 off of it and slug just .173. In his last full season before that, in 2021, the sweeper garnered just a .067 AVG and .067 SLG.

He pairs his sweeper with a sinker, and while it may not have the video-game numbers his sweeper has, it still caused hitters problems with a .222 AVG against and .365 SLG against in 2024.

While his numbers may be great and are too good not to have within the Top 20, it’s hard to push him significantly higher than this on account that he’ll be 37 by the time the 2025 season is over and he’s not far removed from missing nearly two full seasons with a major shoulder injury.

17. Bryan Abreu (Houston Astros)

2024 Stats: 78 G, 78.1 IP, 3.10 ERA, 1.16 WHIP, 3.49 FIP, 11.8 K/9, 3.7 BB/9

Finkelstein	Morgenstern	Treuden	Appel	Leighton	McMullen
RANK: 16	RANK: 23	RANK: 20	RANK: 17	RANK: 22	RANK: 14

After lighting the league up in both 2022 and 2023 with sub-2.00 ERAs, Bryan Abreu found himself coming back down to earth slightly in 2024.

While his stat line was nothing to dismiss by any means, a 3.10 ERA, 3.49 FIP, 1.16 WHIP and .206 AVG against doesn’t have that same oomph that his 1.75 ERA, 2.98 FIP, 1.04 WHIP and .174 AVG against had the year prior.

While his strikeout ability may’ve declined last season as well, by no means was he suddenly not a strikeout-oriented arm, as his 31.7% K-rate placed him in the 93rd percentile of league arms while his 34.0% whiff rate landed in the 95th percentile.

Abreu also found a way to control the walks to a better degree last season. It still was not a great clip, but dipping below 10% for the first time in the last four seasons has to be worth something.

While his slider remained an effective weapon last season, with a .166 AVG and .227 SLG, his secondary four-seamer took a hit in 2024, with opponents hitting .262 and slugging .500 against it as opposed to the .163 AVG and .256 clips it produced in ’23.

If Abreu can continue to remain one of the league’s top strikeout-oriented arms, continue to show improvements in his walk rates and reign in his four-seamer, there’s no reason why he can’t climb this list come 2026 as one of the league’s premier set-up men.

16. Luke Weaver (New York Yankees)

2024 Stats: 62 G, 4 SV, 84.0 IP, 2.89 ERA, 0.93 WHIP, .173 BAA, 3.33 FIP, 11.0 K/9, 2.8 BB/9

Finkelstein	Morgenstern	Treuden	Appel	Leighton	McMullen
RANK: 18	RANK: 30	RANK: 16	RANK: 16	RANK: 15	RANK: 16

After Clay Holmes pitched his way out of the closer’s role in 2024, Luke Weaver took the ball and ran with it, anchoring the Yankees’ pennant-winning ‘pen down the stretch.

There was a lot to love about Weaver’s game in 2024 after converting to a full-time relief role, such as a sub-3.00 ERA, a sub-1.00 WHIP and a sub-.200 AVG against.

And how could we forget about the postseason masterclass he put together for the Yankees? He pitched to a 1.76 ERA and 0.65 WHIP with 16 Ks and just two walks in 15.1 innings of work.

He was also one of the league’s premier strikeout arms, as his 31.1% K-rate and 33.5% whiff rate all ranked well above the 90th percentile and his 84th percentile 31.9% chase rate was nothing to breeze over either.

Everything Weaver threw at hitters was virtually unhittable, as his four-seamer, changeup and cutter all produced sub-.200 AVG against marks.

That being said though, when hitters did connect on Weaver’s offerings, they did so in a loud way. He produced a very pedestrian-looking 38.4% hard-hit rate placing him just in the 52nd percentile. On top of that, his 89.1 mph AVG exit velocity ranked in the 41st percentile and his 8.6% barrel rate fell within just the 30th percentile.

He left a lot to be desired as well when it came to limiting walks, as a 7.9% walk rate placed him in just the 51st percentile.

The fact he likely won’t be closing games for New York now that Devin Williams is in the picture also hurts his value as a reliever to a certain degree, but he remains one of the league’s premier back-end arms and is ranked accordingly amongst MLB’s top set-up arms.

15. Jason Adam (San Diego Padres)

2024 Stats: 74 G, 4 SV, 73.2 IP, 1.95 ERA, 0.86 WHIP, .158 BAA, 3.03 FIP, 9.9 K/9, 2.8 BB/9

Finkelstein	Morgenstern	Treuden	Appel	Leighton	McMullen
RANK: 14	RANK: 30	RANK: 14	RANK: 19	RANK: 11	RANK: 18

Next, we move to, dare I say, one of the top acquisitions of last summer’s trade deadline: Jason Adam.

It’s pretty hard to get better than the 2.98 ERA, 1.01 WHIP and .181 AVG against season he put together in Tampa in 2023, but he managed it with a sub-2.00 ERA, a sub-1.00 WHIP and a sub-.160 AVG against.

Looking at how he adjusted to his new surroundings in San Diego was remarkable as well, as in 26.2 innings of post-trade deadline work, the 33-year-old posted a 1.01 ERA, 2.45 FIP, 0.79 WHIP and .152 AVG against.

Adam not only has the ability to sit guys down, with a 28.7% K-rate, but he has the ability to make them look overmatched, with a 99th percentile whiff rate of 38.4%.

Now as good as he has been, there are some areas in which he isn’t as strong as others, such as the quality of contact he surrenders.

In 2024 Adam ranked in just the 58th percentile in both hard-hit rate (37.8%) and AVG exit velocity (88.5%) while only inducing groundballs at 54th percentile clip (43.0%).

Walks were another element of mediocrity for Adam, as his 8.2% walk rate landed in just the 47th percentile of league arms.

This might be nitpicking though as he still trended average in these areas and his stat line was nothing short of dominant.

The same argument goes for Adam as it does for the majority of guys already mentioned to this point, he’s one of the game’s top non-closing backend arms and is ranked as such.

14. Edwin Díaz (New York Mets)

2024 Stats: 54 G, 20 SV, 53.2 IP, 3.52 ERA, 1.04 WHIP, .187 BAA, 3.02 FIP, 14.1 K/9, 3.4 BB/9

Finkelstein	Morgenstern	Treuden	Appel	Leighton	McMullen
RANK: 17	RANK: 6	RANK: 15	RANK: 8	RANK: 19	RANK: 17

Now we really start to enter the closer’s realm with arms like Edwin Díaz, who made nothing short of an admirable return to the mound in 2024 after missing the entirety of the season prior.

Was the blaring of Timmy Trumpet ahead of the ninth as fear-inducing as it was at the peak of his powers in 2022? No.

However, a season with a 1.04 WHIP and .187 AVG against is nothing to dismiss by any means, as it’s a testament to how he continued to keep hitters on their toes.

While 2024 may not have rendered the same 50.2% strikeout rate that 2022 did, a 38.9% mark last season still placed him in the 100th percentile of league arms, only trailing the Athletics’ Mason Miller.

Díaz was also extremely successful in his pursuit of limiting hard contact, ranking in the 97th percentile in both hard-hit rate (30.3%) and AVG exit velocity (85.9%).

There were some concerns in 2024 that limited such a traditionally dominant arm like Díaz to a lower-half ranking on this year’s list.

One of which was his walk rate, as he rose from a 7.7% mark in 2022 to a 9.3% mark in 2024.

Díaz’s barrel rate was also cause for concern, as it went from an undoubted strength in 2022 at a 93rd-percentile 4.4% clip to just a 59th-percentile 7.3% posting in 2024.

This resulted in a hike in his HR/9 totals, as his 1.17 HR/9 clip ranked him 126th among qualified relievers, and marked a stark contrast with the 0.44 HR/9 total he posted in ’22 that placed him 25th in the league.

Even though he showed a few more holes in his game than he had in years past, there’s still no denying that he’s one of the league’s most difficult arms to face out of the ‘pen.

13. Ryan Walker (San Francisco Giants)

2024 Stats: 76 G, 10 SV, 80.0 IP, 1.91 ERA, 0.85 WHIP, .177 BAA, 2.52 FIP, 11.1 K/9, 2.0 BB/9

Finkelstein	Morgenstern	Treuden	Appel	Leighton	McMullen
RANK: 15	RANK: 12	RANK: 13	RANK: 12	RANK: 14	RANK: 15

Last season marked the changing of the guard in the closing role in San Francisco, as Ryan Walker broke through and established himself as their clear-cut bullpen anchor over Camilo Doval.

While his sub-2.00 ERA and sub-1.00 WHIP season looked fantastic overall, when Walker assumed the closer’s role after his first save on Aug. 10, he was on a new level entirely.

In 19.2 innings across 17 appearances from that point onwards, he posted a 0.92 ERA, a 0.76 WHIP, and a .145 AVG against with 10 saves.

Looking at 2024 in its entirety again, Walker’s success came from having no real weakness.

From a strikeout perspective, he posted a 94th percentile K-rate (32.1%) and a 74th percentile whiff rate (28.6%).

From a control standpoint, he avoided issuing free passes to opposing hitters, posting a respectable 5.8% clip.

All the while he also limited quality contact against him to a high degree, ranking in the 98th percentile in hard-hit rate (30.2%), the 94th percentile in AVG exit velocity (86.4 mph) and the 81st percentile in barrel rate (6.0%).

He achieved all of this with a successful sinker/slider combination, where his sinker saw hitters post just a .201 AVG and .264 SLG against it, while his slider boasted a .157 AVG and .269 SLG against.

The fact that he’s yet to have a full year occupying the ninth inning at the major league level is a reason as to why he’s not amongst the league’s best closing arms on this list. However, he’s demonstrated all the required skills to be a prime candidate to rise on this list in next year’s rendition of it.

12. Justin Martínez (Arizona Diamondbacks)

2024 Stats: 64 G, 8 SV, 72.2 IP, 2.48 ERA, 1.31 WHIP, 2.59 FIP, 11.3 K/9, 4.5 BB/9

Finkelstein	Morgenstern	Treuden	Appel	Leighton	McMullen
RANK: 12	RANK: 14	RANK: 12	RANK: 15	RANK: 12	RANK: 10

The next guy on our list is the 23-year-old Justin Martínez, who has some of the best stuff in all of baseball.

After not even making the Diamondbacks’ Opening Day roster in 2024, Martínez took the league by storm with a sub-2.50 ERA. This marked a stark contrast from the 10.0-inning cameo he had in ’23 where he posted a very inflated 12.60 ERA.

Strikeouts and the avoidance of hard contact were the recipe for success for the crafty righty.

Martínez sat in the 89th percentile in K-rate (29.5%) and the 96th percentile in whiff rate (34.5%) last season.

Then from a quality of contact standpoint, he ranked above the 94th percentile or higher in hard-hit rate, barrel rate, AVG exit velocity and groundball rate.

As I alluded to earlier, this was all on the back of one of the best pitch arsenals in all of baseball.

His primary sinker is blisteringly quick, averaging out at 100.2 mph. Pair that with a less utilized four-seam fastball that also reaches triple-digits and it’s easy to see why he’s ranked within the 100th percentile in fastball velocity.

Going back to sinker though, as fast as it runs, it’s also his kryptonite, as hitters managed to post a .325 AVG against it last season. That’s quite high for a pitch used more than 40% of the time.

He makes up for that though with a pair of elite secondary offerings in his splitter and his slider.

His splitter saw hitters manage just a .098 AVG and .122 SLG off it while inducing an astronomical 54.0% whiff rate. His slider also kept hitters at bay, with a .178 AVG, .289 SLG and a 45.1% whiff rate.

Looking to 2025, if Martínez can control his fastball a bit more and lower his walk rate from a 10th-percentile 11.7% mark, while still leaning on his stellar secondary offerings, there’s no reason to believe that he’s not a prime candidate to exceed expectations once again.

11. Josh Hader (Houston Astros)

2024 Stats: 71 G, 34 SV, 71.0 IP, 3.80 ERA, 0.96 WHIP, .171 BAA, 3.50 FIP, 13.3 K/9, 3.2 BB/9

Finkelstein	Morgenstern	Treuden	Appel	Leighton	McMullen
RANK: 11	RANK: 11	RANK: 11	RANK: 13	RANK: 13	RANK: 12

Then there’s Josh Hader, who may’ve fallen from grace a bit from his top-end status in years past, but is still more than worthy of being a fixture in this Top 20 list.

Hader remained one of the top strikeout-geared relievers in baseball in 2024, with a 37.8% K-rate, a 40.5% whiff rate and a 33.4% chase rate.

He also managed to lower his WHIP in 2024, despite a hike in ERA, dipping below 1.00 for the first time since 2021.

His sinker/slider combination proved to be tough for hitters to generate anything against, as both saw AVG against clips under .200.

Where the concerns come into play is the quality of contact he induces when he’s not mowing hitters down.

Last season Hader fell in just the 49th percentile of league arms in hard-hit rate at 38.8%. Meanwhile posted some putrid marks in AVG Exit Velocity (25th percentile), barrel rate (ninth percentile) and groundball rate (second percentile).

This resulted in Hader becoming more susceptible to homers again, going from a 0.48 HR/9 total in 2023 and reverting back to more of the 1.44 HR/9 arm he was in 2022 after posting a 1.52 HR/9, his highest mark since 2019.

All of this looks worse when you also consider the fact that Hader is not strong at limiting the free pass, with yet another season with a walk rate of 9.0% or higher, his seventh in his eight big league campaigns.

Consistency was also an issue with Hader in 2024, as he’d have months like May at a 1.35 ERA or August at 0.68 ERA, but he’d also have months like April at a 7.45 ERA or September at a 6.75 ERA.

If he can revert back to his better quality of contact form and gain a little more consistency from month to month, then the Top 10 conversation could be a possibility come 2026.

10. Raisel Iglesias (Atlanta Braves)

2024 Stats: 66 G, 34 SV, 69.1 IP, 1.95 ERA, 0.74 WHIP, .156 BAA, 2.65 FIP, 8.8 K/9, 1.7 BB/9

Finkelstein	Morgenstern	Treuden	Appel	Leighton	McMullen
RANK: 9	RANK: 16	RANK: 8	RANK: 14	RANK: 8	RANK: 13

Now we move into the top half of our reliever rankings, meaning less nit-picking and more appreciating just why these are the 10 best relievers in baseball.

Who better to kick it all off with than the closer for a Braves team synonymous with great bullpens in recent years, Raisel Iglesias?

After posting sub-3.00 ERAs, sub-1.20 WHIPs and sub-.215 AVGs against in seven of his previous eight seasons entering 2024, he took things to a new level last season when he threw to a sub-2.00, sub-0.80 WHIP and a sub-.160 AVG against.

He struck hitters out over 26% of the time and paired that with even more impressive whiff and chase rates (31.5% and 37.1% respectively).

He doesn’t walk hitters much, only doing so 5.0% of the time, and he doesn’t surrender much quality contact at all, with 95th percentile marks or better in hard-hit rate, barrel rate and AVG exit velocity.

To add another feather to his cap, regardless of which pitch he threw from his fairly evenly split four-pitch-mix, odds are opponents weren’t hitting it. Each of his four offerings held AVG against totals below .180, and just one of his pitches saw a SLG above .300 (his four-seam fastball at .328).

With no holes to poke in his game and such a consistent track record of high-level production in relief, the 35-year-old is still more than worthy of a Top 10 spot, even as he presumably is on the back-nine of his MLB career.

9. Griffin Jax (Minnesota Twins)

2024 Stats: 72 G, 10 SV, 71.0 IP, 2.03 ERA, 0.87 WHIP, .181 BAA, 1.94 FIP, 12.0 K/9, 1.9 BB/9

Finkelstein	Morgenstern	Treuden	Appel	Leighton	McMullen
RANK: 10	RANK: 9	RANK: 10	RANK: 11	RANK: 10	RANK: 9

Griffin Jax went from really good, to flat-out great in 2024, following two very solid campaigns in 2022 and 2023 that put him on the map.

He elevated himself from a guy comfortably in the mid-to-low 3.00s in ERA, low 1.00s in WHIP and mid-to-low .200s in AVG against, to a low 2.00s ERA, sub-1.00 WHIP and sub-.200 BAA arm last season.

He raised his K-rate nearly 10%, going from a 24.8% clip to a 34.4% clip and paired that with insane 98th and 99th percentile rates in whiff% and chase% respectively.

He walked hitters just 5.4% of the time, down 1.5% from his 2023 mark, and did his best to keep whatever contact hitters managed to get off of him on the ground, with a groundball rate above 50.0% (52.1%).

While he did surrender higher hard-hit rates, barrel rates and AVG exit velocities, it didn’t coincide with a rise in HR/9, as that stat actually went down for him in 2024 from a 0.69 mark in ’23 to 0.51.

With Twins closer Jhoan Duran (who we’ll discuss momentarily) looking easier to solve than we’ve become accustomed to in recent years, Jax will inevitably have an even more critical role to play for the squad in 2025.

8. Jhoan Durán (Minnesota Twins)

2024 Stats: 58 G, 23 SV, 54.1 IP, 3.64 ERA, 1.16 WHIP, 2.85 FIP, 10.9 K/9, 2.5 BB/9

Finkelstein	Morgenstern	Treuden	Appel	Leighton	McMullen
RANK: 8	RANK: 7	RANK: 9	RANK: 7	RANK: 9	RANK: 6

I spoiled this one a bit already, but Jhoan Durán is next on our list, and despite some slightly worse numbers in certain areas in 2024, he still holds a firm place among the best bullpen arms in baseball.

While his ERA may’ve jumped into the mid-3.00s and his fastball looked more hittable – with a .296 AVG in ’24 compared to a .213 AVG in ’23 – many of his underlying metrics remained top-tier.

Even with a four percent drop in K-rate from 2023, his 28.9% posting still placed him within the 88th percentile of the league, paired with an even more impressive 93rd percentile whiff rate.

Durán also saw a notable decline in his walk rate, as he went from walking guys at a 9.8% mark, to reverting back to the BB% in and around 6.0%.

He was a master at avoiding barrels, only surrendering them at a 3.5% clip, which in turn resulted in a 99th percentile ground ball rate of 61.7%.

And while he may’ve seen more struggles with his fastball last year than in seasons past, his secondary pitches were more than adequate. His splitter reduced hitters to just a .238 AVG and a sub-.400 SLG, while his curveball went a third consecutive season under a .200 AVG.

Despite the rise in some surface-level numbers, the underlying metrics tell a story of an arm that is as strong as any elite MLB reliever.

7. Ryan Helsley (St. Louis Cardinals)

2024 Stats: 65 G, 49 SV, 66.1 IP, 2.04 ERA, 1.10 WHIP, 2.41 FIP, 10.7 K/9, 3.1 BB/9

Finkelstein	Morgenstern	Treuden	Appel	Leighton	McMullen
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Ryan Helsley certainly left the “saves-truthers” satisfied in 2024, leading the major leagues in saves at 49.

However, this past season was more than just saves for the 30-year-old righty, as he turned in yet another impressive stat line with some strong underlying metrics to go along with it.

His 2.04 ERA and 2.41 FIP marked the third straight campaign that he’s gone sub-2.50 in both stats, while his 1.10 WHIP and .206 AVG against constituted the highest marks he posted in the same three-year span.

Helsley remained one of the toughest relievers to touch last season, sitting within the 90th percentile rate or higher in strikeout, chase and whiff rates.

Opponents also found getting solid contact off of him a challenge, as his hard-hit rate sat in the upper quarter of league arms and he missed barrels at a 97th percentile clip.

He’s got an ideal pitch makeup for a reliever, with a seemingly untouchable slider (.171 AVG and 51.0% whiff rate) and a blistering fastball sitting at 99 mph comfortably. Then he can drop an intermittent curveball to throw hitters off (6.2% usage rate with .125 AVG and 47.1% whiff).

He could stand to keep the ball on the ground more often (37.2%), especially with a 32nd percentile AVG exit velocity. Walking less batters wouldn’t hurt either (8.6% BB%).

That being said though, he’s found immense success for three straight seasons now, showing his shortcomings aren’t debilitating in the slightest.

6. Cade Smith (Cleveland Guardians)

2024 Stats: 74 G, 75.1 IP, 1.91 ERA, 0.90 WHIP, .190 BAA, 1.40 FIP, 12.3 K/9, 2.0 BB/9

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Now we add a bit of Canadian contingency to the list with Cade Smith, fresh off as strong a rookie season as anyone could’ve imagined.

The 25-year-old right-hander went from a seemingly last-minute choice to break camp to a pivotal backend reliever for a Cleveland Guardians squad that was just a few wins away from a World Series appearance in 2024.

His sterling stat line, along with his major league-leading 2.7 fWAR amongst relief pitchers, resulted in a ninth-place finish in AL Cy Young voting and a fifth-place finish in AL Rookie of the Year voting.

Smith’s combination of a 35.6% strikeout rate and a 5.9% walk rate truly makes him one of the toughest outs in the game with a K/BB rate of 6.06, the 10th best clip among all qualified major league relievers.

His outstanding ALDS performance against the Tigers was the prime example of this, as he struck 12 and walked just one in 6.1 innings of work.

He’s aided by the successful four-seam/splitter combo at the top of his three-pitch arsenal, accounting for nearly 90% of his pitches and both holding sub-.200 AVGs and sub-.300 SLGs.

While he’ll have to continue to put up performances like these moving forward to retain such high regard in the relief pitching community, a 97th percentile xERA of 2.55 and a 94th percentile xBA of .193 leaves a lot of hope that this wasn’t simply a “flash-in-the-pan” type season for Smith.

5. Tanner Scott (Los Angeles Dodgers)

2024 Stats: 72 G, 22 SV, 72.0 IP, 1.75 ERA, 1.13 WHIP, .175 BAA, 2.92 FIP, 10.5 K/9, 4.5 BB/9

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There’s no better way to describe Tanner Scott, other than one of the best relievers MLB has seen in the past two seasons.

His 2.04 combined ERA ranks fourth amongst qualified relievers and he’s accumulated the highest fWAR amongst his bullpen compatriots in that span.

Looking at the 2024 season in particular, it was a special year for the 30-year-old southpaw when you focus on that glimmering stat line.

His underlying metrics also tell the story though of his sheer dominance across the board.

He’s one of the best at avoiding hard contact, as his 27.5% hard-hit rate last season landed him in the 99th percentile of league arms, while his 4.7% barrel rate fell in the 92nd percentile and his 84.3 mph AVG exit velocity was in the 100th percentile.

That stands alongside his elite ability to sit hitters down, with an 86th percentile K-rate (28.6%), a 92nd percentile whiff rate (32.7%) and an 84th percentile chase rate (31.9%)

With relief pitching being so stuff-oriented, his four-seam fastball was yet again a consistent source of immense success for him. He accompanied it with a very solid slider.

His four-seamer left hitters helpless, with a .134 AVG against and a .179 SLG, while his slider held its own with a .231 AVG and .316 SLG against it.

He now takes his talents to Los Angeles with a Dodgers organization that time and time again finds ways to get the absolute best out of their bullpen arms, meaning the good times could keep on rolling for this top-tier arm.

4. Devin Williams (New York Yankees)

2024 Stats: 22 G, 14 SV, 21.2 IP, 1.25 ERA, 0.97 WHIP, 2.06 FIP, 15.8 K/9, 4.6 BB/9

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Moving into our top four now, we get into the guys who were all consensus top five relief arms amongst our panel of voters. We start this group with the air-bender himself in Devin Williams.

Williams returned from injury in 2024 and put together yet another season on par with the insane stretch of top-notch seasons he’s strung together in recent years.

It was his third straight season with a sub-2.00 ERA and sub-3.00 FIP for the 30-year-old, and his second straight season with a sub-1.00 WHIP and sub-.150 AVG against.

While he’s walked hitters at a more than 12.0% clip in his last four seasons, he’s made up for that with an over 37% K-rate in each of those years, including two seasons above a 40.0% clip.

He also continued the trend of being a tough arm for opposing hitters to generate solid contact against, as in 2024 he posted a 32.4% hard-hit rate, a 5.4% barrel rate and an immaculate 84.2 mph AVG exit velocity.

It wouldn’t be an analysis of Williams without discussing his disgusting pitch mix, with a changeup and four-seam fastball that have held hitters to sub-.200 AVGs and sub-.300 SLGS in each of the last three seasons.

His biggest knock is that he hasn’t been the best performer in the postseason, however now that he’s on the Yankees, he’ll continue to have a chance to right those October wrongs.

3. Félix Bautista (Baltimore Orioles)

2024 Stats: DID NOT PITCH

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Even after missing all of 2024 due to Tommy John recovery, it’s hard not to look at Félix Bautista and not see a top-five MLB reliever.

Bautista’s 2023 All-Star campaign saw him lead the league in fWAR alongside Scott, while his 1.48 ERA, 1.88 FIP, 0.92 WHIP, .155 AVG against and 46.4% K-rate all ranked within the top five totals amongst qualified relievers.

Despite looking average in 2023 when it came to missing barrels (48th percentile at 8.1%) and limiting strong exit velos (58th percentile at 88.6 mph), he showed he was able to keep the ball in the ballpark to an admirable 0.59 HR/9 clip.

This was in large part thanks to the fact he struck out guys nearly half the time, but also limited his hard-hit rate to just 34.3%, placing him in the 81st percentile.

His four-seam/splitter combo accounted for over 95% of pitches in 2023, and both were elite offerings, holding hitters to sub-.160 AVGs and sub-.250 SLGs.

In his two major league seasons so far, he’s been able to noticeably been able to improve each season. So if he can return from injury in 2025 and look at least similar to what he was before he went down, he’ll have a serious case to give our unanimous top two relievers a run for their money.

2. Mason Miller (Athletics)

2024 Stats: 55 G, 28 SV, 65.0 IP, 2.49 ERA, 0.88 WHIP, .159 BAA, 2.18 FIP, 14.4 K/9, 2.9 BB/9

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While Smith may’ve bested Mason Miller in the fWAR race, Miller had the advantage in accolades in 2024, making an All-Star team and finishing one spot better than him in AL Rookie of the Year voting (4th).

It’s hard to look at Miller’s Baseball Savant page and not be blinded by red, as his excellent underlying metrics played a huge role in producing the elite stat line he did in 2024.

Miller’s stuff looked as unhittable as any, as opponents struck out 41.8% of the time (100th percentile), whiffed at a 40.1% rate (100th percentile) and chased pitches 37.4% of the time (92nd percentile).

When hitters did manage to make contact against him, they only did so 32.5% of the time (92nd percentile) and found the barrel at just a 5.7% clip (82nd percentile).

This all came from a stellar 1-2 combo at the top of his pitch mix. His primary four-seamer is blazingly fast and held hitters to just a .178 AVG and .319 SLG, while his secondary slider left hitters looking foolish with a .140 AVG, .186 SLG and 44.4% whiff rate.

It may have just been his official rookie season, but his 100th percentile xERA (1.77) and xBA (.150) make it easy to dream on Miller maintaining his pace as one of the league’s best relievers for years to come.

1. Emmanuel Clase (Cleveland Guardians)

2024 Stats: 74 G, 47 SV, 74.1 IP, 0.61 ERA, 0.66 WHIP, .151 BAA, 2.22 FIP, 8.0 K/9, 1.2 BB/9

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Emmanuel Clase is our unanimous No. 1 reliever for 2025 and it’s not difficult to see why after one of the best seasons for a relief pitcher in recent memory, resulting in a third-place finish in AL Cy Young voting.

He led the league in ERA by such a large margin that if you were to double his 0.61 ERA, it would only fall just 0.05 behind Kirby Yates’ second-best 1.17 ERA.

He also led the league in WHIP, sat top five in fWAR, saves, AVG against and BB/9, and ranked in the top 10 in FIP.

Looking at things from more of a macro lens, 2024 marked the third season in his last four in which he threw to a sub-1.50 ERA, sub-2.50 FIP, sub-1.00 WHIP and a sub-.200 AVG against.

Now Clase isn’t like the majority of arms on this list, where strikeouts dominate their game. He’s ranked under the 25% threshold in K-rate the past two seasons as a matter of fact.

However, he lives off of inducing weak contact, keeping the ball on the ground and avoiding issuing walks.

His hard-hit rate (29.7%), barrel rate (3.6%) and AVG exit velocity all ranked (86.5 mph) ranked in the 92nd percentile or better.

He kept the ball on the ground 57.8% of the time, which was good enough to place him within the 95th percentile of league arms.

Clase’s 3.7% walk rate was also amongst the league’s best, sitting in the 98th percentile in 2024.

It’s been his cutter/slider combination at the center of his success. Last season he threw his cutter over 77% of the time and held opposing hitters to just a .150 AVG and .209 SLG. Then he’d toss in a slider around 20% of the time to keep hitters on their toes, resulting in a .145 AVG and .161 SLG against it.

Clase is like no other reliever in baseball and has used that to his advantage, separating himself as the clear best bullpen arm in all of MLB entering 2025.