Single Season Winning Percentage Leaders

  Rank Player Percentage Year Age  
  1. Roy Face .947 1959 31  
  2. Johnny Allen .938 1937 31  
  3. Phil Regan .933 1966 29  
  4. Perry Werden .923 1884 18  
  5. Larry Twitchell .917 1887 23  
  6. Greg Maddux .905 1995 29  
  7. Randy Johnson .900 1995 31  
  8. Ron Guidry .893 1978 27  
  9. Freddie Fitzsimmons .889 1940 38  
  10. Lefty Grove* .886 1931 31  
  11. Bob Stanley .882 1978 23  
  12. Cliff Lee .880 2008 29  
  13. Preacher Roe .880 1951 36  
  14. Tom Seaver* .875 1981 36  
  15. Ron Davis .875 1979 23  
  16. Deacon Phillippe .875 1910 38  
  17. Fred Goldsmith .875 1880 24  
  18. Joe Wood .872 1912 22  
  19. Roger Clemens .870 2001 38  
  20. David Cone .870 1988 25  
  21. Roger Moret .867 1973 23  
  22. Orel Hershiser .864 1985 26  
  23. Whitey Ford* .862 1961 32  
  24. Bill Donovan .862 1907 30  
  25. Daisuke Matsuzaka .857 2008 27  
  26. Jason Bere .857 1994 23  
  27. Roger Clemens .857 1986 23  
  28. Dwight Gooden .857 1985 20  
  29. Mike Nagy .857 1969 21  
  30. Eddie Yuhas .857 1952 27  
  31. Eddie Rommel .857 1929 31  
  32. Charlie Hodnett .857 1884 23  
  33. Harry Wheeler .857 1878 20  
  34. Pedro Martinez .852 1999 27  
  35. John Smoltz .850 1998 31  
  36. Chief Bender* .850 1914 30  
  37. Lefty Grove* .848 1930 30  
  38. Mike Hampton .846 1999 26  
  39. Preacher Roe .846 1952 37  
  40. Ellis Kinder .846 1951 36  
  41. Ron Perranoski .842 1963 27  
  42. Ralph Terry .842 1961 25  
  43. Sandy Consuegra .842 1954 33  
  44. Schoolboy Rowe .842 1940 30  
  45. Emil Yde .842 1924 24  
  46. Tom Hughes .842 1916 32  
  47. Lefty Gomez* .839 1934 25  
  48. Denny McLain .838 1968 24  
  49. Bill Hoffer .838 1895 24  
  50. Walter Johnson* .837 1913 25  
  51. Pedro Martinez .833 2002 30  
  52. Randy Johnson .833 1997 33  
  53. Julian Tavarez .833 1995 22  
  54. Marvin Freeman .833 1994 31  
  55. Sandy Koufax* .833 1963 27  
  56. Hoyt Wilhelm* .833 1952 29  
  57. Spud Chandler .833 1943 35  
  58. King Cole .833 1910 24  
  59. Henry Boyle .833 1884 23  
  60. Charley Radbourn* .831 1884 29  
  61. Randy Johnson .828 2002 38  
  62. Greg Maddux .826 1997 31  
  63. Elmer Riddle .826 1941 26  
  64. Ed Reulbach .826 1906 23  
  65. Roy Oswalt .824 2001 23  
  66. Juan Guzman .824 1993 26  
  67. Roger Moret .824 1975 25  
  68. Wayne Simpson .824 1970 21  
  69. Bob Moose .824 1969 21  
  70. Dazzy Vance* .824 1924 33  
  71. Jack Chesbro* .824 1902 27  
  72. Jay Hughes .824 1899 25  
  73. Al Orth .824 1899 26  
  74. Barry Zito .821 2002 24  
  75. Bob Purkey .821 1962 32  
  76. Chief Bender* .821 1910 26  
  77. Roger Clemens .818 2004 41  
  78. David Wells .818 1998 35  
  79. Joe Boever .818 1994 33  
  80. Mark Portugal .818 1993 30  
  81. Bob Welch .818 1990 33  
  82. Sal Maglie .818 1950 33  
  83. Joe McGinnity* .814 1904 33  
  84. Jorge Sosa .813 2005 28  
  85. Jamie Moyer .813 1996 33  
  86. Moose Haas .813 1983 27  
  87. Al Hrabosky .813 1975 25  
  88. Tommy John .813 1974 31  
  89. Al McBean .813 1963 25  
  90. Jim Coates .813 1960 27  
  91. Bob Feller* .813 1954 35  
  92. Rip Sewell .813 1948 41  
  93. Howie Krist .813 1942 26  
  94. Atley Donald .813 1939 28  
  95. Carl Hubbell* .813 1936 32  
  96. Eddie Plank* .813 1912 36  
  97. Russ Ford .813 1910 27  
  98. Mordecai Brown* .813 1906 29  
  99. Hooks Wiltse .813 1904 24  
  100. Dizzy Dean* .811 1934 24  

Active players in bold. (*)Hall of Fame Member.