Isolated Power
All-Time Single-Season Z-Leaders
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Babe Ruth* (14)
1920 #1
1921 #2
1919 #3
1918 #4
1927 #5
1924 #7
1926 #8
1923 #9
1928 #11
1929 #21
1922 #24
1930 #30
1931 #46
1932 #69
Ted Williams* (7)
1946 #33
1942 #35
1957 #44
1941 #62
1949 #80
1954 #85
1947 #91
Barry Bonds (6)
2001 #6
2004 #17
2002 #18
2003 #38
1992 #39
1993 #90
Jimmie Foxx* (6)
1932 #13
1933 #22
1939 #76
1934 #87
1938 #89
1935 #119
Lou Gehrig* (5)
1927 #10
1934 #42
1931 #56
1936 #70
1930 #71
Mark McGwire* (5)
1998 #12
1995 #20
1999 #34
1992 #43
1996 #45
Johnny Mize* (4)
1940 #23
1938 #94
1947 #112
1939 #138
Gavvy Cravath* (4)
1915 #27
1917 #54
1914 #101
1913 #146
Hank Greenberg* (4)
1946 #32
1938 #57
1935 #83
1940 #130
Rogers Hornsby* (3)
1925 #16
1922 #37
1924 #58
Mike Schmidt* (3)
1980 #26
1981 #31
1979 #109
Ralph Kiner* (3)
1949 #52
1947 #72
1951 #114
Dick Allen* (3)
1972 #55
1966 #142
1968 #147
Harry Stovey* (3)
1891 #84
1880 #100
1884 #137
Dan Brouthers* (2)
1881 #28
1886 #132
Hank Aaron* (2)
1971 #41
1969 #117
Mickey Mantle* (2)
1956 #47
1961 #92
Sam Thompson* (2)
1895 #51
1894 #115
Willie Stargell* (2)
1971 #53
1973 #81
Dave Kingman* (2)
1979 #63
1976 #135
Ty Cobb* (2)
1917 #66
1908 #121
Hack Wilson* (2)
1930 #74
1927 #123
Cy Williams* (2)
1923 #82
1916 #96
Chuck Klein* (2)
1932 #88
1933 #152
Willie Mays* (2)
1965 #93
1964 #103
Reggie Jackson* (2)
1969 #102
1980 #108
Dave Orr (2)
1885 #111
1886 #120
This chart lists the top 1% of all player-seasons.
Active players in bold, asterisk (*) means HOF.
See historical isolated power graph.
| Player | Year / Lg | ISO | Z-Score | |
|---|---|---|---|---|
| 1. | Babe Ruth* | 1920 AL | .473 | 6.7734 |
| 2. | Babe Ruth* | 1921 AL | .469 | 6.2710 |
| 3. | Babe Ruth* | 1919 AL | .336 | 5.4605 |
| 4. | Babe Ruth* | 1918 AL | .256 | 5.4189 |
| 5. | Babe Ruth* | 1927 AL | .417 | 5.1926 |
| 6. | Barry Bonds | 2001 NL | .536 | 5.1155 |
| 7. | Babe Ruth* | 1924 AL | .361 | 5.0394 |
| 8. | Babe Ruth* | 1926 AL | .366 | 4.8714 |
| 9. | Babe Ruth* | 1923 AL | .372 | 4.8711 |
| 10. | Lou Gehrig* | 1927 AL | .392 | 4.7838 |
| 11. | Babe Ruth* | 1928 AL | .386 | 4.7461 |
| 12. | Mark McGwire* | 1998 NL | .454 | 4.7291 |
| 13. | Jimmie Foxx* | 1932 AL | .385 | 4.5598 |
| 14. | Buck Freeman | 1899 NL | .245 | 4.4354 |
| 15. | Jimmy Wood | 1872 NA | .221 | 4.4265 |
| 16. | Rogers Hornsby* | 1925 NL | .353 | 4.4260 |
| 17. | Barry Bonds | 2004 NL | .450 | 4.3220 |
| 18. | Barry Bonds | 2002 NL | .429 | 4.2104 |
| 19. | Kevin Mitchell* | 1989 NL | .344 | 4.1585 |
| 20. | Mark McGwire* | 1995 AL | .410 | 4.1047 |
| 21. | Babe Ruth* | 1929 AL | .353 | 4.0659 |
| 22. | Jimmie Foxx* | 1933 AL | .347 | 4.0604 |
| 23. | Johnny Mize* | 1940 NL | .321 | 4.0361 |
| 24. | Babe Ruth* | 1922 AL | .357 | 4.0297 |
| 25. | John Anderson | 1898 NL | .212 | 3.9926 |
| 26. | Mike Schmidt* | 1980 NL | .338 | 3.9827 |
| 27. | Gavvy Cravath* | 1915 NL | .224 | 3.9684 |
| 28. | Dan Brouthers* | 1881 NL | .222 | 3.9526 |
| 29. | Tip O'Neill | 1887 AA | .255 | 3.9391 |
| 30. | Babe Ruth* | 1930 AL | .373 | 3.9057 |
| 31. | Mike Schmidt* | 1981 NL | .328 | 3.8913 |
| 32. | Hank Greenberg* | 1946 AL | .327 | 3.8767 |
| 33. | Ted Williams* | 1946 AL | .325 | 3.8419 |
| 34. | Mark McGwire* | 1999 NL | .418 | 3.8304 |
| 35. | Ted Williams* | 1942 AL | .291 | 3.8146 |
| 36. | Honus Wagner* | 1908 NL | .188 | 3.8096 |
| 37. | Rogers Hornsby* | 1922 NL | .321 | 3.8077 |
| 38. | Barry Bonds | 2003 NL | .408 | 3.8032 |
| 39. | Barry Bonds | 1992 NL | .313 | 3.7869 |
| 40. | John Bass | 1871 NA | .337 | 3.7860 |
| 41. | Hank Aaron* | 1971 NL | .341 | 3.7733 |
| 42. | Lou Gehrig* | 1934 AL | .344 | 3.7723 |
| 43. | Mark McGwire* | 1992 AL | .317 | 3.7682 |
| 44. | Ted Williams* | 1957 AL | .343 | 3.7424 |
| 45. | Mark McGwire* | 1996 AL | .418 | 3.7216 |
| 46. | Babe Ruth* | 1931 AL | .328 | 3.7005 |
| 47. | Mickey Mantle* | 1956 AL | .353 | 3.6971 |
| 48. | Jim Thome | 2002 AL | .373 | 3.6915 |
| 49. | Ned Williamson* | 1884 NL | .276 | 3.6717 |
| 50. | Willie McCovey* | 1969 NL | .336 | 3.6665 |
| 51. | Sam Thompson* | 1895 NL | .262 | 3.6608 |
| 52. | Ralph Kiner* | 1949 NL | .348 | 3.6486 |
| 53. | Willie Stargell* | 1971 NL | .333 | 3.6335 |
| 54. | Gavvy Cravath* | 1917 NL | .193 | 3.6239 |
| 55. | Dick Allen* | 1972 AL | .294 | 3.6181 |
| 56. | Lou Gehrig* | 1931 AL | .321 | 3.5977 |
| 57. | Hank Greenberg* | 1938 AL | .369 | 3.5667 |
| 58. | Rogers Hornsby* | 1924 NL | .272 | 3.5344 |
| 59. | Albert Belle* | 1995 AL | .374 | 3.5340 |
| 60. | Rudy York* | 1943 AL | .256 | 3.5310 |
| 61. | George Hall | 1876 NL | .179 | 3.5197 |
| 62. | Ted Williams* | 1941 AL | .329 | 3.5034 |
| 63. | Dave Kingman* | 1979 NL | .325 | 3.4989 |
| 64. | Charlie Keller* | 1943 AL | .254 | 3.4942 |
| 65. | Bill Joyce | 1894 NL | .293 | 3.4827 |
| 66. | Ty Cobb* | 1917 AL | .187 | 3.4825 |
| 67. | Cecil Fielder* | 1990 AL | .314 | 3.4780 |
| 68. | Stan Musial* | 1948 NL | .326 | 3.4623 |
| 69. | Babe Ruth* | 1932 AL | .319 | 3.4620 |
| 70. | Lou Gehrig* | 1936 AL | .342 | 3.4519 |
| 71. | Lou Gehrig* | 1930 AL | .343 | 3.4496 |
| 72. | Ralph Kiner* | 1947 NL | .326 | 3.4412 |
| 73. | Wally Berger* | 1933 NL | .254 | 3.4409 |
| 74. | Hack Wilson* | 1930 NL | .368 | 3.4283 |
| 75. | Jose Bautista | 2010 AL | .357 | 3.4232 |
| 76. | Jimmie Foxx* | 1939 AL | .334 | 3.4219 |
| 77. | Ed Delahanty* | 1896 NL | .234 | 3.4119 |
| 78. | Sammy Sosa | 2001 NL | .409 | 3.4108 |
| 79. | Dolph Camilli* | 1941 NL | .270 | 3.4086 |
| 80. | Ted Williams* | 1949 AL | .307 | 3.4075 |
| 81. | Willie Stargell* | 1973 NL | .347 | 3.4052 |
| 82. | Cy Williams* | 1923 NL | .282 | 3.4001 |
| 83. | Hank Greenberg* | 1935 AL | .300 | 3.3976 |
| 84. | Harry Stovey* | 1891 NL | .219 | 3.3963 |
| 85. | Ted Williams* | 1954 AL | .290 | 3.3885 |
| 86. | Jim Bottomley* | 1928 NL | .304 | 3.3870 |
| 87. | Jimmie Foxx* | 1934 AL | .319 | 3.3834 |
| 88. | Chuck Klein* | 1932 NL | .298 | 3.3834 |
| 89. | Jimmie Foxx* | 1938 AL | .356 | 3.3828 |
| 90. | Barry Bonds | 1993 NL | .341 | 3.3771 |
| 91. | Ted Williams* | 1947 AL | .292 | 3.3462 |
| 92. | Mickey Mantle* | 1961 AL | .370 | 3.3357 |
| 93. | Willie Mays* | 1965 NL | .328 | 3.3277 |
| 94. | Johnny Mize* | 1938 NL | .277 | 3.3237 |
| 95. | Fred Dunlap* | 1884 UA | .209 | 3.3119 |
| 96. | Cy Williams* | 1916 NL | .180 | 3.2985 |
| 97. | Frank Robinson* | 1966 AL | .321 | 3.2969 |
| 98. | Travis Hafner | 2006 AL | .350 | 3.2946 |
| 99. | Carlos Pena | 2007 AL | .345 | 3.2934 |
| 100. | Harry Stovey* | 1880 NL | .189 | 3.2896 |
| 101. | Gavvy Cravath* | 1914 NL | .200 | 3.2893 |
| 102. | Reggie Jackson* | 1969 AL | .333 | 3.2870 |
| 103. | Willie Mays* | 1964 NL | .311 | 3.2839 |
| 104. | David Ortiz | 2006 AL | .349 | 3.2819 |
| 105. | Carl Yastrzemski* | 1967 AL | .295 | 3.2672 |
| 106. | Jeff Bagwell* | 1994 NL | .383 | 3.2652 |
| 107. | Frank Thomas | 1994 AL | .376 | 3.2647 |
| 108. | Reggie Jackson* | 1980 AL | .298 | 3.2581 |
| 109. | Mike Schmidt* | 1979 NL | .311 | 3.2580 |
| 110. | Jim Rice* | 1978 AL | .285 | 3.2441 |
| 111. | Dave Orr | 1885 AA | .200 | 3.2360 |
| 112. | Johnny Mize* | 1947 NL | .312 | 3.2227 |
| 113. | Mel Ott* | 1938 NL | .271 | 3.2225 |
| 114. | Ralph Kiner* | 1951 NL | .318 | 3.2205 |
| 115. | Sam Thompson* | 1894 NL | .279 | 3.2105 |
| 116. | Al Simmons* | 1930 AL | .327 | 3.2100 |
| 117. | Hank Aaron* | 1969 NL | .307 | 3.2082 |
| 118. | Cy Seymour* | 1905 NL | .182 | 3.2059 |
| 119. | Jimmie Foxx* | 1935 AL | .290 | 3.2056 |
| 120. | Dave Orr | 1886 AA | .189 | 3.2009 |
| 121. | Ty Cobb* | 1908 AL | .151 | 3.1979 |
| 122. | Goose Goslin* | 1930 AL | .326 | 3.1955 |
| 123. | Hack Wilson* | 1927 NL | .261 | 3.1858 |
| 124. | Ripper Collins | 1934 NL | .282 | 3.1855 |
| 125. | Larry Walker* | 1997 NL | .354 | 3.1564 |
| 126. | Harmon Killebrew* | 1967 AL | .289 | 3.1547 |
| 127. | Ken Griffey | 1997 AL | .342 | 3.1535 |
| 128. | Sherry Magee* | 1914 NL | .195 | 3.1460 |
| 129. | Bill Nicholson* | 1943 NL | .222 | 3.1445 |
| 130. | Hank Greenberg* | 1940 AL | .330 | 3.1357 |
| 131. | Henry Larkin | 1885 AA | .196 | 3.1357 |
| 132. | Dan Brouthers* | 1886 NL | .211 | 3.1341 |
| 133. | Nap Lajoie* | 1901 AL | .217 | 3.1333 |
| 134. | Ken Williams* | 1925 AL | .282 | 3.1286 |
| 135. | Dave Kingman* | 1976 NL | .268 | 3.1216 |
| 136. | Mel Ott* | 1932 NL | .283 | 3.1059 |
| 137. | Harry Stovey* | 1884 AA | .219 | 3.1043 |
| 138. | Johnny Mize* | 1939 NL | .277 | 3.1013 |
| 139. | Frank Schulte* | 1911 NL | .234 | 3.0943 |
| 140. | Darryl Strawberry* | 1988 NL | .276 | 3.0865 |
| 141. | Javy Lopez | 2003 NL | .359 | 3.0796 |
| 142. | Dick Allen* | 1966 NL | .315 | 3.0705 |
| 143. | Joe Medwick* | 1937 NL | .267 | 3.0697 |
| 144. | Roger Maris* | 1961 AL | .351 | 3.0689 |
| 145. | Alex Rodriguez | 2007 AL | .331 | 3.0621 |
| 146. | Gavvy Cravath* | 1913 NL | .227 | 3.0539 |
| 147. | Dick Allen* | 1968 NL | .257 | 3.0526 |
| 148. | Charley Jones | 1879 NL | .194 | 3.0521 |
| 149. | Cal McVey* | 1875 NA | .162 | 3.0516 |
| 150. | Ken Williams* | 1922 AL | .296 | 3.0499 |
| 151. | Albert Pujols | 2009 NL | .331 | 3.0488 |
| 152. | Chuck Klein* | 1933 NL | .234 | 3.0479 |