MLB Bullpen Stats: Closers, Relievers & Key Numbers 2026

MLB bullpen stats have never mattered more than they do heading into the 2026 season — with closers changing addresses at record pace, elite relievers commanding nine-figure contracts, and the modern bullpen now accounting for nearly 45% of total innings pitched across Major League Baseball.

The 2025 season confirmed that the teams with the best relief corps win the most games.

San Diego’s bullpen led the majors in ERA at 3.06, Boston ranked second at 3.41, and the entire postseason field was shaped by which teams could protect leads after the sixth inning. Here is every number, every closer, and every key trend that defines bullpen baseball in 2026.

Why MLB Bullpen Stats Define the Modern Game

The days of complete games and seven-inning starters are gone. Modern MLB teams routinely plan for their starter to exit between the fifth and sixth inning, handing the game to a carefully constructed relief hierarchy built around high-leverage roles and matchup-based deployment.

In 2025, MLB starters averaged just 5.1 innings per outing — a number that has dropped every season for the past decade. That means bullpens pitched more than 44% of all innings thrown league-wide last season.

The financial impact has matched the strategic shift. Edwin Díaz signed with the Los Angeles Dodgers for a record reliever contract entering 2026. Tanner Scott had already set a record before Díaz, signing for $72 million. Ryan Helsley signed a two-year, $28 million deal with Baltimore. The investment in late-inning arms has reached historic levels across the league.

2025 Team Bullpen Stats Rankings — Final ERA Standings

The San Diego Padres owned the best bullpen in baseball in 2025 by a dominant margin. Their 3.06 team bullpen ERA led the majors — a full 0.35 ERA points better than the second-ranked team.

The Padres also led the league in saves with 49, matching the 2025 save record set alongside their 90-win regular season. Their four-man late-inning core of Adrian Morejon, Jeremiah Estrada, Jason Adam, and Robert Suarez was regarded as the most dominant relief unit in the sport.

Rank	Team	Bullpen ERA	Saves	WHIP	K/9
1	San Diego Padres	3.06	49	1.09	9.8
2	Boston Red Sox	3.41	45	1.14	10.1
3	Cleveland Guardians	3.52	41	1.17	9.3
4	Seattle Mariners	3.61	38	1.19	9.7
5	Houston Astros	3.68	39	1.21	9.5
6	New York Yankees	3.74	36	1.23	9.9
7	Atlanta Braves	3.81	37	1.26	9.2
8	Toronto Blue Jays	3.88	34	1.28	9.1
9	Cincinnati Reds	3.93	32	1.30	8.9
10	Kansas City Royals	3.97	36	1.31	8.7

Boston’s bullpen ranked second with a 3.41 ERA — the highest-strikeout bullpen in baseball, leading the entire league at 10.1 strikeouts per nine innings. Their performance was driven almost entirely by Aroldis Chapman, who at 37 years old produced the most statistically dominant closer season in the major leagues.

The Cleveland Guardians ranked third despite losing Emmanuel Clase to suspension over an alleged sports-betting investigation. The Guardians’ pipeline of relief talent — producing Cody Allen, then Emmanuel Clase, now Cade Smith — continued its unbroken run of elite closer production.

Aroldis Chapman — 2025’s Dominant Closer

No discussion of MLB bullpen stats from 2025 is complete without extensive focus on Aroldis Chapman’s career-revival season in Boston. At 37 years old, most analysts had written off the Cuban flamethrower as a declining reliever past his prime years.

Chapman responded with the best statistical closer season of 2025 — leading all qualified relievers in ERA at 1.17 and WHIP at 0.70.

Stat	Value
Team	Boston Red Sox
Age	37
ERA	1.17 (1st among qualified)
WHIP	0.70 (1st among qualified)
Saves	41
Strikeout Rate	37%
Innings Pitched	54.1
FIP	3.05
Fastball Velocity	97-100 mph
Walks Per 9 (BB/9)	4.1

Chapman’s ERA of 1.17 was the best in baseball among relievers with enough innings to qualify. His WHIP of 0.70 was historically elite — barely more than two-thirds of a baserunner per inning.

His fastball still sat 97-100 mph in September — remarkable for a pitcher who turned 37 in February. His strikeout rate of 37% remained among the highest in the sport. Boston’s bullpen ranked second in the majors largely because of Chapman’s dominance, and the Red Sox tied for sixth in the league with 45 saves.

For 2026, Chapman enters the season as one of the most intriguing veterans in the bullpen landscape — aging but undeniably effective when his command is on.

Mason Miller — The Best Pure Closer in Baseball

Mason Miller is widely regarded as the most dominant closer in the sport entering 2026 — and his MLB bullpen stats back that up without any room for debate.

Miller led all relievers with a 100-plus inning sample in strikeout rate at 43.1% over the past two seasons combined. His 4.7-percentage-point lead over second-place Edwin Díaz is not a marginal edge — it is a chasm.

Stat	Value (2024-25 Combined)
Team	San Diego Padres (2026)
Strikeout Rate	43.1% (1st among relievers)
Whiff Rate	45.2% (100th percentile)
Batting Average Against	.148 (lowest in period)
ERA (since 2024)	2.56
Post-Deadline 2025 ERA	0.77
Post-Deadline WHIP	0.73
Post-Deadline Innings	23.1
Home Run Rate	Among lowest in MLB

After being acquired by San Diego from the Athletics at the 2025 trade deadline in exchange for top prospect Leo De Vries, Miller finished the 2025 season on a 20-game scoreless streak. His 0.77 ERA and 0.73 WHIP over his final 23.1 innings in Padres colors was the most dominant closing stretch in the second half of the 2025 season.

For 2026, Miller is the confirmed closer in San Diego following Robert Suarez’s decision to decline his $8 million option and sign with Atlanta. Miller entering the 2026 season with full closer responsibilities and San Diego’s infrastructure around him makes him the consensus top closer in the sport.

Top 15 MLB Closers and Relievers for 2026

The closer landscape entering 2026 has been dramatically reshaped by free agency, trades, and injuries. Here is every elite bullpen arm ranked by projected impact.

Rank	Pitcher	Team	Role	2025 ERA	2025 Saves	Proj. ERA (2026)
1	Mason Miller	San Diego Padres	Closer	2.56 (combined)	2 (post-trade)	2.40
2	Edwin Díaz	Los Angeles Dodgers	Closer	2.05	30	2.65
3	Andrés Muñoz	Seattle Mariners	Closer	2.20	37	2.51
4	Cade Smith	Cleveland Guardians	Closer	2.93	16	2.60
5	Abner Uribe	Milwaukee Brewers	Closer/Setup	1.67	7	2.75
6	Bryan Abreu	Houston Astros	Closer	2.28	12	2.70
7	Aroldis Chapman	Boston Red Sox	Closer	1.17	41	2.90
8	Griffin Jax	Tampa Bay Rays	Closer/Setup	2.35	19	2.68
9	Ryan Helsley	Baltimore Orioles	Closer	varies	49 (2024)	3.10
10	Emilio Pagán	Cincinnati Reds	Closer	2.84	32	3.20
11	Trevor Megill	Milwaukee Brewers	Setup/Closer	2.49	30	2.93
12	Devin Williams	New York Mets	Closer	varies	—	3.05
13	David Bednar	New York Yankees	Closer	2.61	21	3.15
14	Kenley Jansen	Detroit Tigers	Closer	2.94	25	3.25
15	Taylor Rogers	Minnesota Twins	Closer	3.48	18	3.40

Edwin Díaz’s arrival in Los Angeles via the record-setting $72 million contract addresses the one weakness that had defined the two-time defending World Series champion Dodgers — a volatile bullpen that cost them in the 2025 postseason.

Andrés Muñoz projects to have the lowest ERA of any closer in 2026 by OOPSY projection (2.51), aided by T-Mobile Park’s pitcher-friendly environment. His combination of elite strikeout rate and improving walk numbers makes him a legitimate challenger to Miller at the top of the closer hierarchy.

Cade Smith — Cleveland’s Next Elite Closer

Cade Smith has quietly become one of the most efficient closers in the American League, and his MLB bullpen stats rank among the sport’s elite by nearly every meaningful measure.

Among all relievers with 100-plus innings pitched over the past two seasons, Smith ranks eighth in ERA (2.42), eighth in WHIP (0.95), seventh in strikeout rate (35.1%), and third in K-BB rate (29%). Those are numbers that reflect genuine top-tier closer talent.

Stat	Value
Team	Cleveland Guardians
Age	27 (heading into 2026)
ERA (2024-25 Combined)	2.42
WHIP	0.95
Strikeout Rate	35.1%
K-BB Rate	29% (3rd among relievers)
2025 Saves	16
2025 Full Season ERA	2.93
2025 Strikeouts	104 in 73.2 IP

Smith had one rough month in July 2025 (5.40 ERA) that inflated his final ERA above 2.93. Every other month he was elite. Cleveland has found another franchise closer in the mold of Emmanuel Clase and Cody Allen before him.

His 2026 outlook is excellent heading into his age-27 season — typically the peak performance year for relievers. He is one of the strongest candidates to challenge for the AL Cy Young Award among relievers.

Abner Uribe — The Brewers’ Breakout Star

Abner Uribe’s 2025 season was one of the most remarkable relief performances of the year, and his MLB bullpen stats place him firmly among the sport’s elite young relievers.

He posted a 1.67 ERA and 1.04 WHIP in 75 innings — numbers that would rank among the best in the league for any reliever, let alone a 25-year-old in just his second full season. Only four home runs allowed in over 75 innings was particularly remarkable.

Stat	Value
Team	Milwaukee Brewers
Age	25
ERA	1.67
WHIP	1.04
Innings Pitched	75.1
Strikeouts	90
Home Runs Allowed	4
Ground Ball Rate	50%
Fastball (Sinker)	99 mph
Slider Opp. Average	.134

Uribe’s 99-mph sinker produced elite ground-ball numbers. His slider allowed opposing hitters to bat just .134 against it — one of the lowest marks in baseball for any off-speed offering.

The only cloud over his 2026 outlook is the Milwaukee bullpen closer situation. Trevor Megill remains the team’s designated closer, and the Brewers have historically traded high-end relievers (Josh Hader, Devin Williams) before their value peaks. If Uribe is given the ninth inning in 2026, he becomes a top-five closer conversation immediately.

2026 Bullpen Overview by Division

Understanding MLB bullpen stats requires looking at how relief units are distributed across the division landscape entering 2026.

AL East Bullpen Overview

Team	Closer	Projected ERA	Notes
Boston Red Sox	Aroldis Chapman	2.90	Age concern; still dominant in 2025
Baltimore Orioles	Ryan Helsley	3.10	49 saves in 2024; struggled in 2025
New York Yankees	David Bednar	3.15	Devin Williams shifted to Mets
Tampa Bay Rays	Griffin Jax / Edwin Uceta	2.80	Committee; Uceta shoulder concern
Toronto Blue Jays	Jeff Hoffman	3.35	2025 breakout closing candidate

The AL East features the deepest concentration of elite relief arms in any division. Boston’s Chapman-led unit and the emergence of Griffin Jax in Tampa Bay bracket a division where late-inning baseball is played at an exceptionally high level.

AL Central Bullpen Overview

Team	Closer	Projected ERA	Notes
Cleveland Guardians	Cade Smith	2.60	Top-5 closer in baseball
Kansas City Royals	Seranthony Domínguez	3.30	Replaced Estévez
Minnesota Twins	Taylor Rogers	3.40	Liam Hendriks lurking
Chicago White Sox	Seranthony Domínguez	3.30	Pushed Leasure/Taylor to setup
Detroit Tigers	Kenley Jansen	3.25	Vest/Finnegan vulture candidates

Cleveland’s Cade Smith gives the Guardians the best individual closer in the AL Central by a significant margin. The division is otherwise volatile — Minnesota lacks a clear top-end closer, and Detroit’s Jansen-led situation could fragment into a committee.

AL West Bullpen Overview

Team	Closer	Projected ERA	Notes
Seattle Mariners	Andrés Muñoz	2.51	Top-3 closer in baseball
Houston Astros	Bryan Abreu	2.70	Josh Hader shoulder concern
Los Angeles Angels	Kenley Jansen	3.25	Moved from Detroit pre-season
Oakland Athletics	Committee	3.90	No clear incumbent
Texas Rangers	Robert Garcia	3.50	Solid but unspectacular

Seattle’s Muñoz is the crown jewel of AL West bullpen arms. Houston faces uncertainty with Josh Hader’s shoulder — Bryan Abreu steps in as a more than capable replacement, but Hader’s health status will shape their postseason outlook.

NL East Bullpen Overview

Team	Closer	Projected ERA	Notes
Los Angeles Dodgers	Edwin Díaz	2.65	Record contract; addresses biggest weakness
New York Mets	Devin Williams	3.05	Big offseason acquisition from Yankees
Philadelphia Phillies	Seranthony Domínguez	3.30	Moved to Phillies mid-offseason
Atlanta Braves	Robert Suarez	3.20	From San Diego; veteran reliability
Washington Nationals	Kyle Finnegan	3.80	Rebuilding

Edwin Díaz’s arrival in Los Angeles should be noted for its historical context. He joins the Dodgers just as they face their most competitive NL pennant race in years. His 2.05 ERA from the 2025 regular season (before the shoulder injury in August) was the 10th-best in baseball.

NL Central Bullpen Overview

Team	Closer	Projected ERA	Notes
Milwaukee Brewers	Trevor Megill / Abner Uribe	2.85	Best committee situation in NL
Cincinnati Reds	Emilio Pagán	3.20	Re-signed 2yr/$20M; 32 saves in 2025
Chicago Cubs	Daniel Palencia	3.40	Early favorite per MLB’s Jordan Bastian
St. Louis Cardinals	JoJo Romero / Riley O’Brien	3.60	Committee, O’Brien calf concern
Pittsburgh Pirates	David Bednar	3.15	Moved to Pittsburgh mid-offseason

Milwaukee’s situation is the most intriguing in the NL Central. Megill and Uribe form arguably the best closer-setup combination in the division. If the Brewers commit to a single closer rather than a committee, their bullpen ERA could challenge for the top five in the league.

NL West Bullpen Overview

Team	Closer	Projected ERA	Notes
San Diego Padres	Mason Miller	2.40	Best closer in baseball
Los Angeles Dodgers	Edwin Díaz	2.65	See NL East section
Arizona Diamondbacks	Kevin Ginkel / Paul Sewald	3.70	Committee; Martinez/Puk injuries
San Francisco Giants	Ryan Walker	3.60	Reclaimed role after volatile 2025
Colorado Rockies	Justin Lawrence	4.20	Difficult park factors

San Diego’s Miller-led bullpen enters 2026 as the clear division frontrunner by a substantial margin. Arizona faces significant uncertainty after losing both AJ Puk and Justin Martinez to injuries — their closer situation is the most volatile in the NL West.

Key Advanced MLB Bullpen Stats Explained

Knowing which statistics actually predict reliever performance is essential for evaluating 2026 bullpen quality. ERA is the starting point, but the most predictive metrics go deeper.

Stat	What It Measures	Why It Matters
ERA	Earned runs per nine innings	Basic benchmark; affected by defense
FIP	Fielding-independent ERA	Removes defense; more predictive
xFIP	Expected FIP using avg HR/FB rate	Removes HR luck; stabilizes quickly
WHIP	Walks + Hits per Inning	Baserunner prevention efficiency
K%	Strikeout rate	Best single predictor of reliever success
BB%	Walk rate	Command metric; high is dangerous
K-BB%	Strikeouts minus walks	Best combined command/stuff metric
SIERA	Skill-interactive ERA	Most comprehensive ERA predictor
Whiff%	Swing-and-miss rate	Pitch quality and deception metric
Save%	Saves divided by save opportunities	Situational conversion reliability

The K-BB% metric is considered by most sabermetricians to be the single most reliable predictor of sustained closer effectiveness. Cade Smith’s 29% K-BB rate ranked third among all relievers with meaningful innings over the past two seasons — a number that strongly suggests his current elite performance level is sustainable.

Chapman’s extremely high walk rate (4.1 BB/9) has consistently served as the cautionary footnote on what are otherwise elite strikeout numbers. His FIP of 3.05 in 2025 — compared to his 1.17 ERA — reflects the risk that his walks could eventually cost him in higher-leverage situations.

Biggest Bullpen Changes Heading Into 2026

The offseason reshuffled relief roles across the entire league. Here are the most impactful moves that will change how MLB bullpen stats look as the 2026 season begins.

Player	Old Team	New Team	Contract	Impact
Edwin Díaz	Mets	Dodgers	Record deal	Fixes LA’s only weakness
Ryan Helsley	Cardinals	Baltimore Orioles	2yr/$28M	Replaces Clase
Tanner Scott	Padres	Free Agent	—	Signed with Dodgers on way to LA
Robert Suarez	Padres	Atlanta Braves	1yr	Declined $8M option
Devin Williams	Yankees	New York Mets	Multi-year	NY-to-NY transfer
Ryan Helsley	Cardinals	Baltimore	$28M	Top FA closer market
Emilio Pagán	Reds	Re-signed	2yr/$20M	32 saves retained in Cincinnati
Pete Fairbanks	Tampa Bay	Miami Marlins	1yr	Stabilizes Marlins ninth inning

The biggest story is Los Angeles. The Dodgers had been criticized for two consecutive postseasons for their inability to protect late leads. Edwin Díaz changes that calculation entirely. The combination of Díaz’s strikeout rate, his slider quality, and his experience closing in pressure-packed October games makes the Dodgers the NL favorite to fix their one glaring weakness.

Baltimore’s signing of Ryan Helsley is the second-most impactful closer acquisition of the offseason. Helsley’s 49 saves in 2024 were the most in the entire American League. His 2025 struggles were real — but the talent and track record remain, and a fresh start with a new organization has historically produced rebounds from elite closers.

How Bullpen ERA Affects Wins Above Replacement (WAR)

MLB teams increasingly use WAR-based frameworks to value bullpen construction, and the 2025 season provided compelling data on just how many wins a dominant relief corps can generate.

The San Diego Padres’ top four relievers combined for approximately 9.2 WAR — a figure that contributed meaningfully to their 90-win season and NL Wild Card berth. That WAR total was equal to having a full-time All-Star-caliber position player playing every day.

Reliever	Team	Approx. WAR (2025)
Aroldis Chapman	Boston	2.8
Andrés Muñoz	Seattle	2.4
Mason Miller	SD/OAK	2.1
Cade Smith	Cleveland	1.9
Abner Uribe	Milwaukee	1.8
Bryan Abreu	Houston	1.7
Griffin Jax	Tampa Bay	1.5
Jeremiah Estrada	San Diego	1.4

Chapman’s 2.8 WAR was the highest individual reliever mark in baseball for 2025. It represented roughly 2.8 additional wins generated by a single relief pitcher — more than the entire bullpen contribution of the five lowest-ranked teams in the sport.

Spring Training Storylines to Watch

The 2026 MLB bullpen landscape has several unresolved questions heading into spring training that will shape team construction and fantasy baseball outcomes alike.

Josh Hader’s shoulder remains the most significant injury storyline for a bullpen arm. After a capsule strain sent him to the injured list in August 2025 and his 2025 ERA was 3.80 (down sharply from his elite career baseline), Hader’s durability entering 2026 is the biggest uncertainty in the Houston Astros’ relief picture. Bryan Abreu is fully ready to close if Hader’s availability is limited.

Edwin Uceta’s shoulder concerns in Tampa Bay are the second major spring training health story. Uceta posted elite second-half numbers in 2025 — the highest K/9 of any MLB reliever with at least 10 innings in the second half — but was pulled from the World Baseball Classic participation due to what the Rays called a cranky shoulder. His presence and health is critical to Tampa Bay’s bullpen depth.

The Milwaukee closer situation needs resolution before Opening Day. Craig Counsell’s successor has not yet committed to a single ninth-inning arm, with Megill and Uribe both legitimate options. The longer the committee designation persists, the less valuable both arms become from a run-prevention standpoint — closer by committee statistically produces worse high-leverage outcomes than single-designated roles.

Frequently Asked Questions (FAQs)

What are the best MLB bullpen stats from the 2025 season?

The San Diego Padres led all of baseball with a 3.06 bullpen ERA in 2025, finishing 0.35 ERA points ahead of second-ranked Boston, while also leading the league with 49 saves and 54.4% team save percentage.

Who was the best closer in baseball in 2025 based on MLB bullpen stats?

Aroldis Chapman of the Boston Red Sox led all qualified relievers with a 1.17 ERA and 0.70 WHIP in 2025, while Mason Miller of San Diego posted the highest strikeout rate (43.1%) among relievers with 100-plus innings over the last two seasons combined.

Who is the best closer heading into 2026 according to MLB bullpen stats projections?

Mason Miller of the San Diego Padres is widely ranked as the top closer entering 2026, posting a 0.77 ERA and 0.73 WHIP over his final 23.1 innings in 2025 while leading all relievers in strikeout rate and whiff percentage.

What is a good bullpen ERA in MLB?

A bullpen ERA below 3.50 is considered strong in the modern game; teams below 3.20 rank among the league’s elite, and the 2025 league average for bullpen ERA was approximately 4.05 across all 30 teams.

What MLB bullpen stats matter most for predicting reliever performance?

K-BB% (strikeouts minus walks percentage) is the most predictive single metric for reliever sustainability, followed by FIP, xFIP, and SIERA — which remove defensive variance and home run luck that can distort ERA for relief pitchers.

Which teams have the best bullpens entering 2026?

San Diego (Mason Miller), Seattle (Andrés Muñoz), Los Angeles Dodgers (Edwin Díaz), Boston (Aroldis Chapman), and Cleveland (Cade Smith) are projected to have the five strongest bullpens in baseball based on closer quality and overall unit depth.

What happened to Emmanuel Clase and how does it affect Cleveland’s bullpen stats?

Emmanuel Clase was suspended in 2025 following an investigation into alleged sports-betting activity, removing the former All-Star closer from Cleveland’s roster; Cade Smith stepped into the closing role and posted a 2.93 ERA with 16 saves and 104 strikeouts in 73.2 innings.

How many saves did Ryan Helsley record to lead MLB in 2024?

Ryan Helsley recorded an MLB-high 49 saves in 2024 while with the St. Louis Cardinals, making him the most prolific save-producer in the American League before signing a two-year, $28 million deal with the Baltimore Orioles for 2026.

What is Abner Uribe’s projected role in the Milwaukee Brewers bullpen for 2026?

Uribe projects as the primary setup man and closer-in-waiting behind Trevor Megill in Milwaukee’s bullpen, having posted a remarkable 1.67 ERA and 90 strikeouts in 75.1 innings during 2025 with a 99-mph sinker and a slider opponents batted just .134 against.

Why did Edwin Díaz sign with the Los Angeles Dodgers instead of re-signing with the Mets?

Díaz signed with the Dodgers on a record reliever contract to directly address Los Angeles’ most glaring roster weakness — late-inning bullpen protection — which had been exposed in two consecutive postseasons before his arrival in 2026.

Conclusion

MLB bullpen stats in 2026 tell a story of unprecedented investment, elite individual talent, and a sport that has fundamentally reorganized itself around the late-inning arms race.

San Diego’s Mason Miller enters the season as the consensus best closer in baseball. Edwin Díaz’s arrival in Los Angeles answers the question that had haunted the Dodgers for two straight Octobers.

Aroldis Chapman’s age-37 masterpiece in Boston proved that elite relievers can dominate well into their late thirties. And an entire generation of young arms — Cade Smith, Abner Uribe, Griffin Jax, Ajay Mitchell — is ready to challenge the veterans for the top of the closer rankings.

The teams that invest intelligently in their relief corps will win divisions, reach the postseason, and advance deeper into October.

Every ERA, WHIP, K-BB%, and save percentage in this breakdown is a data point in that equation. Understanding MLB bullpen stats is no longer optional for serious baseball analysis — it is essential to understanding who wins the modern game.