mlb pitchers highest strikeouts per nine single season relievers

50 pitchers are tied for the best K/9 by a relief pitcher in a season, with 27.00 per nine innings. The first three are Joe La Sorsa and Yunior Marte this season and Jayvien Sandridge in 2025.

	NAME	K/9	SEASON	TM	G	W	L	GS	ERA	SO	CG	SHO	SV	IP	H	ER	R	HR	BB	HBP	GF	IBB	TBF	WP	BB/9	K/BB	HR/9	K%	BB%	WHIP	BABIP	RA	H/9
1	Joe La Sorsa J. La Sorsa	27.00	2026	BOS	1	0	0	0	27.00	1	0	0	0	0.1	1	1	1	1	0	0	1	0	2	0	0.00		27.00	50.0	0.0	3.00		27.00	27.00
2	Yunior Marte Y. Marte	27.00	2026	CIN	1	0	0	0	108.00	1	0	0	0	0.1	3	4	4	0	1	1	0	1	6	0	27.00	1.00	0.00	16.7	16.7	12.00	1.000	108.00	81.00
3	Jayvien Sandridge J. Sandridge	27.00	2025	NYY	1	0	0	0	27.00	2	0	0	0	0.2	1	2	2	1	2	1	0	0	6	0	27.00	1.00	13.50	33.3	33.3	4.50		27.00	13.50
4	Will Warren W. Warren	27.00	2024	NYY	1	0	0	0	27.00	3	0	0	0	1.0	2	3	3	1	1	0	1	0	6	0	9.00	3.00	9.00	50.0	16.7	3.00	1.000	27.00	18.00
5	Evan Justice E. Justice	27.00	2024	COL	1	0	0	0	0.00	1	0	0	0	0.1	0	0	0	0	1	0	1	0	2	0	27.00	1.00	0.00	50.0	50.0	3.00		0.00	0.00
6	Clayton Andrews C. Andrews	27.00	2024	NYY	1	0	0	0	27.00	1	0	0	0	0.1	1	1	1	1	0	1	0	0	3	0	0.00		27.00	33.3	0.0	3.00		27.00	27.00
7	Romy Gonzalez R. Gonzalez	27.00	2021	CWS	1	0	0	0	0.00	1	0	0	0	0.1	0	0	0	0	0	0	1	0	1	0	0.00		0.00	100.0	0.0	0.00		0.00	0.00
8	Kevin Quackenbush K. Quackenbush	27.00	2021	LAD	1	0	0	0	27.00	1	0	0	0	0.1	3	1	1	0	0	0	0	0	4	0	0.00		0.00	25.0	0.0	9.00	1.000	27.00	81.00
9	Nick Maton N. Maton	27.00	2021	PHI	1	0	0	0	0.00	1	0	0	0	0.1	0	0	0	0	0	0	1	0	1	0	0.00		0.00	100.0	0.0	0.00		0.00	0.00
10	Mike Freeman M. Freeman	27.00	2021	CIN	1	0	0	0	0.00	1	0	0	0	0.1	0	0	0	0	0	0	1	0	1	0	0.00		0.00	100.0	0.0	0.00		0.00	0.00
11	Wil Crowe W. Crowe	27.00	2021	PIT	1	0	0	0	13.50	2	0	0	0	0.2	1	1	1	0	2	0	0	0	5	2	27.00	1.00	0.00	40.0	40.0	4.50	1.000	13.50	13.50
12	Chaz Roe C. Roe	27.00	2021	TBR	1	0	0	0	27.00	2	0	0	0	0.2	1	2	2	0	1	0	0	0	4	0	13.50	2.00	0.00	50.0	25.0	3.00	1.000	27.00	13.50
13	Freddy Peralta F. Peralta	27.00	2021	MIL	1	0	0	0	0.00	6	0	0	0	2.0	2	0	0	0	3	0	0	0	11	0	13.50	2.00	0.00	54.5	27.3	2.50	1.000	0.00	9.00
14	Mike Brosseau M. Brosseau	27.00	2020	TBR	1	0	0	0	0.00	1	0	0	0	0.1	0	0	0	0	0	0	1	0	1	0	0.00		0.00	100.0	0.0	0.00		0.00	0.00
15	Jeremy Beasley J. Beasley	27.00	2020	ARI	1	0	0	0	0.00	1	0	0	0	0.1	2	0	0	0	0	0	1	0	3	0	0.00		0.00	33.3	0.0	6.00	1.000	0.00	54.00
16	Tommy Kahnle T. Kahnle	27.00	2020	NYY	1	0	0	0	0.00	3	0	0	0	1.0	1	0	0	0	1	0	0	1	6	0	9.00	3.00	0.00	50.0	16.7	2.00	.500	0.00	9.00
17	Dellin Betances D. Betances	27.00	2019	NYY	1	0	0	0	0.00	2	0	0	0	0.2	0	0	0	0	0	0	0	0	2	0	0.00		0.00	100.0	0.0	0.00		0.00	0.00
18	José Castillo J. Castillo	27.00	2019	SDP	1	0	0	0	0.00	2	0	0	0	0.2	0	0	0	0	1	1	0	0	4	1	13.50	2.00	0.00	50.0	25.0	1.50		0.00	0.00
19	Asher Wojciechowski A. Wojciechowski	27.00	2019	BAL	1	0	0	0	0.00	2	0	0	0	0.2	1	0	0	0	0	0	0	0	3	1	0.00		0.00	66.7	0.0	1.50	1.000	0.00	13.50
20	Jedd Gyorko J. Gyorko	27.00	2019	STL	1	0	0	0	0.00	1	0	0	0	0.1	0	0	0	0	0	0	1	0	1	0	0.00		0.00	100.0	0.0	0.00		0.00	0.00
21	Austen Williams A. Williams	27.00	2019	WSH	2	0	0	0	162.00	1	0	0	0	0.1	5	6	6	2	1	0	0	0	7	0	27.00	1.00	54.00	14.3	14.3	18.00	1.000	162.00	135.00
22	Adrian Sampson A. Sampson	27.00	2018	TEX	1	0	0	0	54.00	1	0	0	0	0.1	4	2	3	1	0	0	0	0	6	0	0.00		27.00	16.7	0.0	12.00	.750	81.00	108.00
23	Danny Valencia D. Valencia	27.00	2018	BAL	1	0	0	0	0.00	1	0	0	0	0.1	0	0	0	0	0	0	1	0	1	0	0.00		0.00	100.0	0.0	0.00		0.00	0.00
24	Jeremy Bleich J. Bleich	27.00	2018	OAK	2	0	0	0	54.00	1	0	0	0	0.1	2	2	2	0	0	1	0	0	4	0	0.00		0.00	25.0	0.0	6.00	1.000	54.00	54.00
25	Roenis Elias R. Elias	27.00	2017	BOS	1	0	0	0	0.00	1	0	0	0	0.1	0	0	0	0	1	0	1	0	2	0	27.00	1.00	0.00	50.0	50.0	3.00		0.00	0.00

Unlock 2x data

StatMuse has game-level data for K/9 going back to the 1901 season.

Some of the information used here was obtained free of charge from Retrosheet.

More MLB News

Nootbaar's leadoff homer, 3 hits spark Diamondbacks in 10-6 victory over Giants

Aug 29, 2026

Mayo, Encarnacion-Strand lift the Orioles past the Athletics, 4-3 in 10 innings

Aug 29, 2026

Edmundo Sosa's pinch-hit grand slam in 9th propels Phillies to a wild 5-3 win over Angels

Aug 29, 2026

Red Sox run themselves into 1-0 loss at Yankee Stadium in series opener

Aug 29, 2026

Freddie Freeman’s late single lifts Dodgers past Tigers in Skubal’s return

Aug 29, 2026

Braves' Ronald Acuña has 3 hits and scores 3 runs in his 1st game hitting cleanup since 2022

Aug 29, 2026

More Red Sox Stats

Team Batting Leaders

26

Contreras

RBI

78

Contreras

AVG

.287

Rafaela

Team Pitching Leaders

16

Gray

141

Tolle

ERA

2.82

Gray

Team Rankings

136

24th

600

16th

1,150

11th

ERA

3.46

3rd

2026 Division Standings

TEAM	W	L	PCT	GB
Rays	80	54	.597
Yankees	76	58	.567	4.0
Red Sox	73	61	.545	7.0
Orioles	66	69	.489	14.5
Blue Jays	66	70	.485	15.0

Schedule

DATE	MATCHUP			TIME (ET)
Sat 8/29	BOS	@	NYY	1:05 PM
Sat 8/29	BOS	@	NYY	7:15 PM
Sun 8/30	BOS	@	NYY	1:35 PM
Mon 8/31	SEA	@	BOS	6:45 PM
Tue 9/1	SEA	@	BOS	6:45 PM

Last Game

Red Sox

73 - 61

Final

Yankees

76 - 58

Fri 28 Aug 2026

MLB 2026 Batting Leaders

HR Leaders

40

Schwarber

37

Olson

36

Goodman

RBI Leaders

102

Stewart

99

Burleson

97

Walker

Batting Average Leaders

.320

Arraez

.318

Alvarez

.309

Simpson

Hit Leaders

163

Arraez

161

Lopez

154

Díaz

Run Leaders

100

Wood

93

Crow-Armstrong

92

Vargas

OBP Leaders

.435

Alvarez

.396

Kurtz

.393

Wood

SLG Leaders

.607

Alvarez

.557

García

.549

Goodman

SB Leaders

43

Nuñez

38

Chisholm

37

Simpson

MLB 2026 Pitching Leaders

Win Leaders

16

Sánchez

16

Gray

15

Griffin

Strikeout Leaders

222

Misiorowski

217

Cease

204

Williams

ERA Leaders

1.73

Misiorowski

2.06

Sale

2.09

Schlittler

WHIP Leaders

0.75

Misiorowski

0.89

Yamamoto

0.93

Rasmussen

K/9 Leaders

13.23

Misiorowski

12.99

Cease

11.77

Williams

K/BB Leaders

6.34

Misiorowski

6.32

Sale

5.72

Rasmussen

Walk Leaders

22

Martinez

25

Rasmussen

28

Sale

MLB Fantasy 2026

FanDuel Points Leaders

2,228.2

Ohtani

1,875.1

Crow-Armstrong

1,785.3

Alvarez

DraftKings Points Leaders

1,565.6

Ohtani

1,425

Crow-Armstrong

1,338

Alvarez

MLB 2026 Betting

Best Record ATS

81-53

78-59

76-59

74-60

75-61

74-61

Worst Record ATS

51-84

54-81

56-79

58-77

61-74

63-72

MLB 2026 Standings

NL East	W	L	PCT	GB
Braves	80	55	.593
Phillies	75	60	.556	5.0
Marlins	68	67	.504	12.0
Nationals	64	73	.467	17.0
Mets	60	75	.444	20.0
NL Central	W	L	PCT	GB
Brewers	84	51	.622
Cubs	76	59	.563	8.0
Cardinals	68	68	.500	16.5
Pirates	65	71	.478	19.5
Reds	64	71	.474	20.0
NL West	W	L	PCT	GB
Dodgers	81	54	.600
Padres	72	63	.533	9.0
Diamondbacks	72	64	.529	9.5
Giants	55	80	.407	26.0
Rockies	52	83	.385	29.0

AL East	W	L	PCT	GB
Rays	80	54	.597
Yankees	76	58	.567	4.0
Red Sox	73	61	.545	7.0
Orioles	66	69	.489	14.5
Blue Jays	66	70	.485	15.0
AL Central	W	L	PCT	GB
White Sox	71	63	.530
Guardians	68	67	.504	3.5
Twins	64	71	.474	7.5
Tigers	62	72	.463	9.0
Royals	61	75	.449	11.0
AL West	W	L	PCT	GB
Astros	68	67	.504
Rangers	66	69	.489	2.0
Mariners	64	71	.474	4.0
Athletics	53	82	.393	15.0
Angels	52	83	.385	16.0

MLB 2026 Scores & Schedule

Scores

DATE	MATCHUP			SCORE
Fri 8/14	STL	@	CHC	0-3
Fri 8/14	MIA	@	CIN	0-1
Fri 8/14	BOS	@	PIT	4-8
Fri 8/14	CWS	@	DET	9-5
Fri 8/14	SDP	@	CLE	7-5

Schedule

DATE	MATCHUP			TIME (ET)
Sat 8/29	BOS	@	NYY	1:05 PM
Sat 8/29	LAD	@	DET	1:10 PM
Sat 8/29	CWS	@	MIN	2:10 PM
Sat 8/29	PIT	@	STL	2:15 PM
Sat 8/29	CIN	@	CHC	2:20 PM

50 pitchers are tied for the best K/9 by a relief pitcher in a season, with 27.00 per nine innings. The first three are Joe La Sorsa and Yunior Marte this season and Jayvien Sandridge in 2025.

Related Searches

More MLB News

More Red Sox Stats

26

78

.287

16

141

2.82

MLB 2026 Batting Leaders

40

37

36

102

99

97

.320

.318

.309

163

161

154

100

93

92

.435

.396

.393

.607

.557

.549

43

38

37

MLB 2026 Pitching Leaders

16

16

15

222

217

204

1.73

2.06

2.09

0.75

0.89

0.93

13.23

12.99

11.77

6.34

6.32

5.72

22

25

28

MLB Fantasy 2026

2,228.2

1,875.1

1,785.3

1,565.6

1,425

1,338

MLB 2026 Betting

MLB 2026 Standings

MLB 2026 Scores & Schedule

Scores

Schedule