League Leaders Who Led?

MLB Single-Season Pitcher Range Factor Record Progression

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

All-time career leaders →

The MLB single-season pitcher range factor record is 5.24, set by Harry Howell in 1905. It has stood for 121 years. The mark has been raised 4 times since 1871.

SS ASS POSS DPSS FPCTSS RFSS GSS E2B A2B PO2B DP2B FPCT2B RF2B G2B E3B A3B PO3B DP3B FPCT3B RF3B G3B EC POC AC DPC FPCTC RFC GC E1B PO1B A1B DP1B FPCT1B RF1B G1B EOF POOF AOF FPCTOF RFOF GOF EP AP POP FPCTP RFP GP E

Record Holders

5 marks since 1871
Year Player P RF Stood for
1905 Harry Howell Harry Howell 5.24 still standing
1904 Harry Howell Harry Howell 4.97 1 year
1882 Will White Will White 4.56 22 years
1875 Tricky Nichols Tricky Nichols 3.56 7 years
1871 Cherokee Fisher Cherokee Fisher 3.17 4 years

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

158 seasons
Year Leader P RF
2025 Max Fried 1.53
2024 Tanner Houck 1.70
2023 Patrick Corbin 1.47
2022 Kyle Wright 1.53
2021 Max Fried 1.61
2020 Kyle Hendricks 1.67
2019 Zack Greinke 2.03
2018 Zack Greinke 1.73
2017 R. A. Dickey 1.90
2016 Mike Leake 2.03
2015 Jake Arrieta 2.49
2014 Dallas Keuchel 2.24
2013 Kyle Kendrick 1.87
2012 Jake Westbrook 1.96
2011 Jake Westbrook 2.18
2010 R. A. Dickey 2.26
2009 Joel Pineiro 1.81
2008 Kenny Rogers 2.53
2007 Tim Hudson 2.06
2007 Greg Maddux 2.06
2007 Brandon Webb 2.06
2006 Jake Westbrook 2.28
2005 Jake Westbrook 2.35
2004 Livan Hernandez 2.34
2003 Tim Hudson 2.18
2002 Odalis Perez 2.31
2001 Greg Maddux 2.15
2000 Greg Maddux 2.66
1999 Greg Maddux 2.64
1998 Greg Maddux 2.77
1997 Kevin Brown 2.42
1996 Greg Maddux 3.09
1995 Kevin Brown 3.15
1994 Greg Maddux 2.32
1993 Greg Maddux 2.72
1992 Greg Maddux 2.69
1991 Greg Maddux 2.41
1990 Greg Maddux 2.69
1989 Tom Candiotti 2.23
1988 Orel Hershiser 2.63
1987 Mike Dunne 2.17
1986 Fernando Valenzuela 2.24
1985 Dave Stieb 2.42
1984 Mike Boddicker 2.88
1983 Jerry Reuss 2.16
1982 Fernando Valenzuela 2.27
1981 John Denny 2.84
1980 Mike Norris 2.33
1979 Mike Caldwell 2.37
1978 John Denny 2.73
1977 Jerry Garvin 2.29
1976 Randy Jones 2.80
1975 Randy Jones 2.27
1974 Mike Torrez 2.09
1973 Tommy John 2.19
1972 Steve Kline 2.19
1971 Steve Kline 2.36
1970 Gaylord Perry 2.37
1969 Mel Stottlemyre 2.87
1968 Tommy John 2.56
1967 Mel Stottlemyre 2.67
1966 Joe Horlen 2.22
1965 Fred Newman 3.00
1964 Larry Jackson 2.73
1963 Warren Spahn 2.49
1962 Bob Purkey 2.27
1961 Bob Purkey 2.72
1960 Vern Law 2.23
1959 Camilo Pascual 2.28
1958 Ned Garver 2.42
1957 Tom Brewer 2.66
1956 Tom Brewer 2.50
1955 Willard Nixon 1.97
1954 Bob Porterfield 2.22
1953 Bob Lemon 2.56
1952 Sid Hudson 2.86
1951 Jim Hearn 2.27
1950 Sid Hudson 2.20
1949 Bob Lemon 2.84
1948 Jonas Gaines 2.82
1947 Jim LaMarque 2.77
1946 Leon Day 2.60
1945 Roy Welmaker 3.07
1944 Gentry Jessup 3.64
1943 Theolic Smith 3.75
1942 Willie Jefferson 3.07
1941 Jim Tobin 2.61
1940 Ray Brown 3.19
1939 Theolic Smith 4.20
1938 Spud Chandler 2.96
1937 Harry Gumbert 2.82
1936 Ray Brown 3.08
1935 Hal Schumacher 3.12
1934 Freddie Fitzsimmons 2.50
1933 Ray Brown 3.80
1932 Goose Curry 3.62
1931 Luther McDonald 3.46
1930 Chet Brewer 4.44
1929 Chet Brewer 3.30
1928 Laymon Yokely 4.41
1927 David Gómez 3.24
1926 Phil Cockrell 3.53
1925 Burleigh Grimes 3.33
1924 Bullet Rogan 3.61
1923 Juanelo Mirabal 3.50
1922 Cool Papa Bell 3.56
1921 Lucas Boada 3.71
1921 Bill Drake 3.71
1920 John Finner 3.68
1919 Scott Perry 3.60
1918 Carl Mays 3.94
1917 Carl Mays 4.00
1916 Carl Mays 2.96
1915 Gene Packard 3.26
1914 Gene Packard 3.48
1913 Jean Dubuc 3.42
1912 George McConnell 3.65
1911 Joe Lake 3.43
1910 Ed Walsh 3.89
1909 Ed Walsh 3.74
1908 Doc White 3.51
1907 Ed Walsh 4.68
1906 Harry Howell 4.06
1905 Harry Howell 5.24 new record
1904 Harry Howell 4.97 new record
1903 Ed Doheny 3.82
1902 Red Donahue 4.14
1901 Jimmy Callahan 3.78
1900 Jimmy Callahan 3.59
1899 Bert Cunningham 3.46
1898 Jack Taylor 3.24
1897 Chick Fraser 3.33
1896 Zeke Wilson 3.27
1895 Cozy Dolan 3.00
1894 Amos Rusie 2.61
1893 Scott Stratton 3.14
1892 Tony Mullane 3.05
1891 Scott Stratton 3.23
1890 Al Maul 3.58
1889 Park Swartzel 2.90
1888 Tom Sullivan 3.54
1887 Bob Caruthers 3.39
1886 Jim Whitney 2.76
1885 Jim McCormick 3.46
1884 John Clarkson 3.14
1883 Jim McCormick 2.77
1882 Will White 4.56 new record
1881 Fred Goldsmith 2.90
1880 Tommy Bond 2.75
1879 Frank Hankinson 3.19
1878 Tricky Nichols 3.00
1877 Jim Devlin 2.30
1876 Tommy Bond 2.62
1875 Tricky Nichols 3.56 new record
1874 Tommy Bond 2.98
1873 Al Spalding 2.68
1872 Al Spalding 2.69
1871 Cherokee Fisher 3.17 new record