Grading past performance and projecting future performance, especially for relief pitchers, can be a difficult task because bullpen success can often times be very random. It’s very common to see relievers and bullpens perform very well one year, and then regress to league average or even below league average from what the numbers show the following year. With pitchers entering games just to record a few outs and then sometimes being bailed out by the next reliever can really skew how we view their overall statistics. When deciding which of the 30 MLB bullpens are the best, I’m not necessarily looking at their performance in 2024, but the structure of their bullpen. I think what makes a bullpen set up for success is:

An established above average closer
Multiple pitchers that can throw multiple quality innings in one outing
A healthy mix of left handed and right handed pitchers

With that being said, here are the five teams that I believe fit that criteria, but also saw a lot of success in 2024 and are building on it heading into the 2025 season.

Kicking off the top 5 is a bullpen that was one of the best in 2024 from a numbers standpoint, that also goes into 2025 with a strong outlook. The Braves had 20 different pitchers log an inning out of the bullpen for them, six of which threw 50+. This group is headlined by the closer Rasiel Iglesias who recorded a career-high 34 saves behind a career-low 1.95 ERA, both of which ranked at least top 15 among qualified relievers. Iglesias is the established closer and foundational piece to this bullpen. Although the Braves will be without Joe Jimenez and are potentially losing A.J. Minter to free agency, some other names that have provided in big ways for Atlanta are Dylan Lee, Pierce Johnson, and Aaron Bummer. Lee is the key left handed arm in this group, logging a 2.11 ERA, 1.11 WHIP, and a 24.6 K-BB% over 59.2 innings. Daysbel Hernandez is an intriguing pitcher that can be the x-factor in this bullpen in 2025. He only threw 18 innings in 2024 but posted a 35.1 K% in the meantime, without allowing a single homerun. Collectively, this bullpen ranked 3rd in ERA (3.32), 2nd in FIP (3.41), 2nd in K% (26.6), and 1st in K-BB% (18.9). They should be projected to rank in the top tier of bullpens once again in 2025.

The Astros come in as the fourth best bullpen going into 2025 after another impressive season along a multi-year stretch of dominance. The bullpen success in Houston is large in part due to the three-headed monster at the back end, that being Josh Hader, Ryan Pressly, and Bryan Abreu. The numbers don’t show that Hader was as good as he’s been in years past, but he still managed to log 34 saves behind a 37.8 K%, 0.96 WHIP, and a .171 BAA. Heading into his age 31 season, I expect him to continue to pitch at a high level. His teammate Pressly is entering his age 36 season but hasn’t really missed a step yet. His numbers have regressed a little with the aging curve, but with Hader taking over the closer role, Pressly doesn’t have to throw in as many high leverage innings. Bryan Abreu also kept up his run of success, throwing a career high in innings to the tune of a 3.10 ERA. This trio of relievers really helps the Astros shorten games. Bryan King is another left handed arm to watch for in 2025 after an impressive showing over 26.1 innings as a rookie. He posted a 2.39 ERA and a 2.71 FIP, while left handed hitters recorded just one extra base hit off of him.

It was hard to leave the Yankees off this list after they acquired who I believe to be the best reliever in all of baseball, that being Devin Williams of course. With former closer Clay Holmes leaving in free agency and taking 30 saves and 63 innings with him, Williams replaces Holmes after his third straight season with a sub-2 ERA. Williams only logged 21.1 innings in 2024 due to injury, but maintained a level of success right in line with his career averages, posting a 1.25 ERA, 2.06 FIP, 0.97 WHIP, and a 43.2 K%. Since the start of 2022 among qualified relievers, Williams ranks 1st in ERA (1.66) and top 3 in FIP (2.29), K% (39.5), and K-BB% (27.2). Before adding him, the Yankees ranked as a top 10 bullpen in ERA (3.62), WHIP (1.24), and BAA (.223). Williams joins Luke Weaver who stepped in as the closer while Clay Holmes struggled towards the end of 2024, and emerged as one of the top arms for the Yankees, posting a 2.89 ERA, 0.93 WHIP, and a 31.1 K% over a whopping 84 innings. Weaver will be able to slot back into the 8th inning setup role and leaving the closing duties to Williams. The addition of Fernando Cruz is one that has flown under the radar as his numbers don’t pop out to you at first, until you see that he has struck out over 35% of the hitters he has faced in each of the last two seasons, and has all the makings of a back end reliever.

It’s hard to make any top 5 list and not include the Dodgers, so I know it’s probably not all that exciting seeing them here, but I have to give credit where credit is due. The interesting thing about this Dodgers bullpen is that they don’t really have the established closer that I’m looking for. However, they have multiple relievers that very well could be that guy. In 2024, they didn’t have one pitcher record at least 20 saves, but they had 14 different pitchers record at least one. Evan Phillips, arguably the best pitcher in the pen, led the way with 18 saves, while Daniel Hudson collected 10. As a group, their 50 saves were the 5th most in baseball. They’ll be missing Brusdar Graterol for at least the first half of the season after his surgery on his torn labrum, but with the depth of this bullpen, his innings will be replaced very well. Perhaps the biggest addition to this staff was Michael Kopech who the Dodgers acquired at last year’s deadline. Since joining the Dodgers, he posted a 1.13 ERA and a 0.79 WHIP over 29 innings, including a solid postseason performance as well. Other pitchers such as Blake Treinen and Alex Vesia continue to pitch at a high level, while resurgences from guys like Anthony Banda and Brent Honeywell have gone a long way. All of these names will be impact arms out of the bullpen in 2025.

Based off of their success in 2024 and what they are bringing into 2025, there was no doubt in my mind that the Guardians would top this list. Since the turn of the century, the 2024 Guardians bullpen ranks 4th in ERA (2.57), 2nd in WHIP (1.05), and 1st in BAA (.200). A large part of this success can be contributed to their closer Emmanuel Clase who just put up one of the best reliever seasons of this decade. Since 2020, Clase’s 2024 ranks 4th in both ERA (0.61) and WHIP (0.66), leading him to a third place finish in the American League Cy Young. He also leads all relievers in fWAR since 2020 with 8.5. Clase is obviously the cornerstone in this bullpen, but don’t overlook the performances from other guys in this group. The rookie Cade Smith had an incredible season, logging a 1.91 ERA, 1.40 FIP, 0.90 WHIP, and a 29.8 K-BB% over a team leading 75.1 IP. He is a great option to take on the setup role for Clase, among other pitchers. Aside from Clase and Smith, two more guys put in 70+ quality innings, that being Pedro Avila and Hunter Gaddis, both of which had outstanding seasons. Tim Herrin also casually put up a 1.92 ERA and a 0.97 WHIP over 65.2 innings. Health will play a factor in whether the Guardians can repeat this or not. It’s not a normal thing to get this kind of quality volume from a bullpen, and they are going to be without Sam Hentges, but will get Trevor Stephan back in the mix sometime in 2025. Regardless, if this core group of guys stays healthy, I like for Cleveland to remain at the top of the pack.

The top 5 bullpens in MLB right now

5. Atlanta Braves

4. Houston Astros

3. New York Yankees

2. Los Angeles Dodgers

Cleveland Guardians