MLB Single-Season Strikeouts / 9 Record Progression

Every season that raised the bar, and the leader in every season between.

The MLB single-season strikeouts / 9 record is 14.20, set by Shane Bieber in 2020. It has stood for 5 years. The mark has been raised 11 times since 1871.

ERA W SO SV WHIP IP K/9 BB/9 K/BB SHO CG GS G L BB W-L%

Record Holders

12 marks since 1871

Year	Player	K/9	Stood for
2020	Shane Bieber	14.20	still standing
2019	Gerrit Cole	13.82	1 year
2001	Randy Johnson	13.41	18 years
1999	Pedro Martinez	13.20	2 years
1998	Kerry Wood	12.58	1 year
1884	Henry Porter	12.53	114 years
1883	Jim Whitney	6.04	1 year
1878	Bobby Mitchell	5.74	5 years
1877	Bobby Mitchell	3.69	1 year
1875	Jack Manning	2.12	2 years
1872	Cherokee Fisher	1.64	3 years
1871	Al Pratt	1.36	1 year

The earliest marks here are records only in the sense that nobody had done better yet. Season length, schedule and the rules themselves have all changed, so a figure from the 1870s is not comparable with a modern one and is not offered as though it were.

Every Season

155 seasons

Year	Leader	K/9
2025	Dylan Cease	11.52
2024	Chris Sale	11.40
2023	Spencer Strider	13.55
2022	Carlos Rodon	11.98
2021	Corbin Burnes	12.61
2020	Shane Bieber	14.20	new record
2019	Gerrit Cole	13.82	new record
2018	Gerrit Cole	12.40
2017	Chris Sale	12.93
2016	Jose Fernandez	12.49
2015	Chris Sale	11.82
2014	Clayton Kershaw	10.85
2013	Yu Darvish	11.89
2012	Max Scherzer	11.08
2011	Zack Greinke	10.54
2010	Tim Lincecum	9.79
2009	Tim Lincecum	10.42
2008	Tim Lincecum	10.51
2007	Erik Bedard	10.93
2006	Jake Peavy	9.56
2005	Mark Prior	10.15
2004	Oliver Perez	10.97
2003	Kerry Wood	11.35
2002	Randy Johnson	11.56
2001	Randy Johnson	13.41	new record
2000	Randy Johnson	12.56
1999	Pedro Martinez	13.20	new record
1998	Kerry Wood	12.58	new record
1997	Randy Johnson	12.30
1996	John Smoltz	9.79
1995	Randy Johnson	12.35
1994	Randy Johnson	10.67
1993	Randy Johnson	10.86
1992	Randy Johnson	10.31
1991	Nolan Ryan	10.56
1990	Nolan Ryan	10.24
1989	Nolan Ryan	11.32
1988	Roger Clemens	9.92
1987	Nolan Ryan	11.48
1986	Mike Scott	10.00
1985	Sid Fernandez	9.51
1984	Dwight Gooden	11.39
1983	Steve Carlton	8.73
1982	Mario Soto	9.57
1981	Steve Carlton	8.48
1980	Mario Soto	8.61
1979	J. R. Richard	9.64
1978	Nolan Ryan	9.97
1977	Nolan Ryan	10.26
1976	Nolan Ryan	10.35
1975	Frank Tanana	9.41
1974	Nolan Ryan	9.93
1973	Nolan Ryan	10.57
1972	Nolan Ryan	10.43
1971	Tom Seaver	9.08
1970	Sam McDowell	8.97
1969	Tom Griffin	9.56
1968	Sam McDowell	9.47
1967	Luis Tiant	9.22
1966	Sam McDowell	10.42
1965	Sam McDowell	10.71
1964	Sam McDowell	9.19
1963	Jim Maloney	9.53
1962	Sandy Koufax	10.55
1961	Sandy Koufax	9.47
1960	Sandy Koufax	10.13
1959	Herb Score	8.23
1958	Sam Jones	8.10
1957	Bob Turley	7.76
1956	Herb Score	9.49
1955	Herb Score	9.70
1954	Billy Pierce	7.06
1953	Vinegar Bend Mizell	6.94
1952	Vinegar Bend Mizell	6.92
1951	Mickey McDermott	6.65
1950	Ewell Blackwell	6.48
1949	Tommy Byrne	5.92
1948	Bob Romby	6.88
1947	Bob Romby	8.00
1946	Hal Newhouser	8.46
1945	Luis Tiant	8.68
1944	Satchel Paige	9.61
1943	Lefty Boone	10.12
1942	Leon Day	8.33
1941	Eugene Smith	8.23
1940	Hilton Smith	8.95
1939	Luis Tiant	8.22
1938	Frank McAllister	8.50
1937	Hilton Smith	6.84
1936	Johnny Taylor	8.80
1935	Luis Tiant	8.04
1934	Satchel Paige	9.39
1933	Satchel Paige	8.81
1932	Red Ruffing	6.60
1931	Ted Trent	7.02
1930	Army Cooper	8.75
1929	Satchel Paige	8.67
1928	Satchel Paige	8.25
1927	Satchel Paige	8.60
1926	Dazzy Vance	7.46
1925	Dazzy Vance	7.50
1924	Dazzy Vance	7.65
1923	Nip Winters	7.25
1922	Dave Brown	5.98
1921	Dave Brown	6.82
1920	Bullet Rogan	7.09
1919	Eric Erickson	5.52
1918	Guy Morton	5.16
1917	Hippo Vaughn	5.94
1916	Larry Cheney	5.91
1915	Pete Alexander	5.76
1914	Dutch Leonard	7.05
1913	Walter Johnson	6.32
1912	Walter Johnson	7.39
1911	Rube Marquard	7.68
1910	Walter Johnson	7.61
1909	Orval Overall	6.47
1908	Rube Waddell	7.31
1907	Rube Waddell	7.33
1906	Red Ames	6.90
1905	Rube Waddell	7.86
1904	Rube Waddell	8.20
1903	Rube Waddell	8.39
1902	Rube Waddell	6.84
1901	Tom Hughes	6.57
1900	Rube Waddell	5.61
1899	Cy Seymour	4.76
1898	Cy Seymour	6.03
1897	Cy Seymour	4.90
1896	Buttons Briggs	3.90
1895	Amos Rusie	4.60
1894	Amos Rusie	3.95
1893	Amos Rusie	3.88
1892	Brickyard Kennedy	5.09
1891	Amos Rusie	6.06
1890	Toad Ramsey	6.63
1889	Jack Stivetts	6.71
1888	Tim Keefe	6.94
1887	Toad Ramsey	5.70
1886	Matt Kilroy	7.92
1885	Lady Baldwin	6.78
1884	Henry Porter	12.53	new record
1883	Jim Whitney	6.04	new record
1882	Bobby Mathews	4.83
1881	George Derby	3.86
1880	Larry Corcoran	4.50
1879	Bill McGunnigle	4.65
1878	Bobby Mitchell	5.74	new record
1877	Bobby Mitchell	3.69	new record
1876	Tommy Bond	1.94
1875	Jack Manning	2.12	new record
1874	Bobby Mathews	1.57
1873	Bobby Mathews	1.60
1872	Cherokee Fisher	1.64	new record
1871	Al Pratt	1.36	new record