40. Fred Lynn 1975 (13.9) He was better in 1979 (15.5). Better, and not by a little bit, in '75 was Joe Morgan (23).
39. Al Rosen 1953 (19.4). This was Rosen's career year; he and Robin Roberts each were 19.4.
38. Alex Rodriguez 1996 (17.5). His best year was 2000 (20). Better in 1996 was Barry Bonds (21.3)
37. Tommy Holmes 1945 (15.1) His career year. Better in '45 was Hal Newhouser (19.9)
36. Albert Pujols 2003 (20.3). His career year. If you hit 20, it's silly to say anyone was better, unless we have a 22-23, but Bonds was 20.6 in 2003.
35. Ken Griffey 1997 (18.2) Griffey's career year. Better in '97 was Roger Clemens (22.1)
34. Jim Rice 1978 (13.7) Rice's career year. Phil Niekro was better (17)
33. Hank Greenberg 1940 (13.1) He had better seasons before '40, and also one after this in '46 (14.8). Bob Feller was 19.6.
32. Rod Carew 1977 (18.9). Carew's career year. He was the best player in '77.
31. Robin Yount 1982 (20.1). Yount's career year. He was the best player in '82.
30. Eric Gagne 2003 (13.2). His best season and a really good season for a closer. Pujols was better and Bonds was better than Pujols.
29. Mark Fidrych 1976 (16.3) His career year. Morgan (17.9) was better.
28. Hank Aaron 1957 (14.5). Had at least a half dozen better years than this. Mickey Mantle (22.1) had a better '57.
27. Nolan Ryan 1973 (15.9). His best year. Joe Morgan (19.9) had a better year.
26. Sammy Sosa 2001 (22.4) His best year. Bonds was better and at 24.8, the current best year on the board.
25. Vida Blue 1971 (16.6) Vida's best year. Fergie Jenkins (19.8) was better.
24. Roger Maris 1961 (10.6) Maris was better in '60 (13.5). Mantle (20.1) was considerably better in '61.
23. Joe Morgan 1976 See #29.
22. Willie Mays 1955 (18.8) Mays had a half dozen better years, but he was also the best player in '55
21. Fernando Valenzuela 1981 (12.7). His best year; Schmidt (16.7) was better.
20. Mark McGwire 1998 (17.3). Mac's best year. Bonds (19.1) it shouldn't surprise you, was better.
19. Roger Clemens 1986 (17.1). Clemens had a couple of better years, his best was in Toronto (see #35). Teddy Higuera had about the same year (17.2)
18. Dwight Gooden 1985 (25). Not only Gooden's best year and the best year for '85 - it's the new best year on the board.
17. Ron Guidry 1978 (17.8). His best season - he was the best player in '78.
16. Stan Musial 1948 (21.2) Musial's best season. He was the best player in '48.
15. Frank Robinson 1966 (17). His best season was '62 (17.7). Koufax (21.5) was the best player in '66.
14. Greg Maddux 1995 (19.5). His best season. He was baseball's best player.
13. Mickey Mantle 1956 (22.4). His best season. He was baseball's best player.
12. Denny McLain 1968 (14.3). His best season. The best player in '68 is still to come on the list.
11. Carl Yastrzemski 1967 (21.5). Yaz's best season. He was best player in '68.
10. Joe Dimaggio 1941 (19.2). His best season. Best player in '41 is a couple of spots away.
9. Randy Johnson 2001 (15.7). Had a couple of seasons a bit better, like '02 for example. See #26 for the best season in '01.
8. Ted Williams 1941 (21.3) He had a better year in '46 (22.8). He was baseball's best in '41.
7. Orel Hershiser 1988 (17.1). His best year. He was baseball's best.
6. Sandy Koufax 1965 (17.9) Was better in both '66 and '63. Mays was best (21.5).
5. Pedro Martinez 1999 (18.2). His best year was the next one, (21.1). He was best player in '99.
4. Steve Carlton 1972 (25). His best year, the best year in '72 and tied with Gooden as the best year on the list.
3. Bob Gibson 1968 (24.9). His best year, he was best in '68.
2. Jackie Robinson 1949 (20.2) His best year, he was best in '49.
1. Barry Bonds 2004 (23.6). His best year was '01, Barry was best in '04.
If you're thinking about all of baseball history - here is a list of the inner circle (20+) seasons. All of them after '40 could have been on this list. There are 42 of those inner circle seasons below; were you doing a list of the 40 best seasons after 1940, you'd start with those. There are 90 seasons total listed below, I could probably do a 100 best seasons in baseball history post someday.
Ruth: 1919, 1920, 1921, 1923, 1924, 1926, 1927, 1931
Bonds: 1992, 1993, 1996, 2001, 2002, 2004
Mays: 1954, 1958, 1962, 1963, 1964, 1965
Walter Johnson: 1910, 1912, 1913, 1914, 1915
Cobb: 1910, 1911, 1917
Clemens: 1990, 1997
Wagner: 1908
Musial: 1948
Williams: 1941, 1942, 1946
Henderson: 1990
Hornsby: 1921, 1924, 1929
Collins: 1913
Gehrig: 1927
Seaver: 1971
Alexander: 1915, 1916, 1920
Mantle: 1956, 1957
Morgan: 1975
Ripken: 1984, 1991
Mathewson: 1908, 1909
Carlton: 1972
Perry: 1972
Gibson: 1968, 1969
Foxx: 1932
Yaz: 1967
Pe Martinez=2000
Yount=1982
Biggio=1997
Clarkson=1885, 1887, 1889
Feller=1946
Keefe=1883
Caruthers=1886, 1887
Boudreau=1948
Sosa=2011
Walsh=1908, 1910, 1912
Radbourn=1883, 1884
Pujols=2003
Gooden=1985
Koufax=1966, 1963
Jackie Robinson=1949
Guy Hecker=1884
Buffinton=1884
Silver King=1888
Rusie=1894
Whitney=1883
Giambi=2001
Cicotte=1917
Banks=1959
Trout=1944
Galvin=1884
Buffinton=1884
Silver King=1888
Rusie=1894
Whitney=1883
Giambi=2001
Cicotte=1917
Banks=1959
Trout=1944
Galvin=1884
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