For single seasons, From 1901 to 2008, (requiring whip≤0.75 and IP≥35), sorted by smallest whip

  Cnt Player             **WHIP**   IP  Year Age Tm  Lg  G  GS CG SHO GF  W  L  W-L% SV  H   R   ER  BB  SO   ERA  ERA  HR  BF   AB  2B 3B IBB HBP  SH  SF GDP  SB CS Pk BK WP   BA   OBP   SLG   OPS  OPS   Pit  Str
 ----+-----------------+---------+-----+----+---+---+--+---+--+--+---+--+--+--+-----+--+---+---+---+---+---+------+----+--+----+----+--+--+---+---+---+---+---+---+--+--+--+--+-----+-----+-----+-----+----+----+---- 
    1 Dennis Eckersley    0.607    57.2 1989  34 OAK AL  51  0  0   0 46  4  0 1.000 33  32  10  10   3  55   1.56  237  5  206  198  4  0   0   1   0   4   2   3  0  0  0  0  .162  .175  .258  .433   22           
    2 Dennis Eckersley    0.614    73.1 1990  35 OAK AL  63  0  0   0 61  4  2  .667 48  41   9   5   4  73   0.61  606  2  262  257  9  1   1   0   0   1   3   1  2  0  0  0  .160  .172  .226  .398   13           
    3 Mariano Rivera      0.616    37.1 2008  38 NYY AL  35  0  0   0 34  2  3  .400 22  20   4   4   3  42   0.96  418  2  133  129  4  0   0   0   0   1   1   3  0  0  0  0  .155  .173  .233  .406    9  520  362 
    4 Eric Gagne          0.692    82.1 2003  27 LAD NL  77  0  0   0 67  2  3  .400 55  37  12  11  20 137   1.20  335  2  306  279  6  0   2   3   4   0   0   2  1  0  0  2  .133  .199  .176  .375    4 1187  824 
    5 J.J. Putz           0.698    71.2 2007  30 SEA AL  68  0  0   0 65  6  1  .857 40  37  11  11  13  82   1.38  314  6  260  242  6  0   0   2   2   1   7   3  0  0  0  3  .153  .202  .252  .454   21 1033  674 
    6 Cla Meredith        0.711    50.2 2006  23 SDP NL  45  0  0   0 11  5  1  .833  0  30   6   6   6  37   1.07  380  3  185  176  2  1   3   2   1   0   4   4  1  0  2  0  .170  .207  .244  .451   23  673  465 
    7 Takashi Saito       0.715    64.1 2007  37 LAD NL  63  0  0   0 55  2  1  .667 39  33  10  10  13  78   1.40  327  5  234  218  4  0   0   3   0   0   7   2  0  0  0  0  .151  .209  .239  .448   17  944  624 
    8 Jake Northrop       0.725    40   1918  30 BSN NL   7  4  4   1  3  5  1  .833  0  26   9   6   3   4   1.35  199  0  150                  0                        0  0                            0           
    9 Joakim Soria        0.730    37   2008  24 KCR AL  35  0  0   0 32  0  1  .000 23  18   5   5   9  41   1.22  348  2  140  126  3  0   0   4   1   0   1   0  1  1  0  1  .143  .223  .214  .437   17  576  385 
   10 Pedro Martinez      0.737   217   2000  28 BOS AL  29 29  7   4  0 18  6  .750  0 128  44  42  32 284   1.74  291 17  817  768 18  1   0  14   2   1  11  10  3  2  0  1  .167  .213  .259  .472   18 3162 2135 

Seasons/Careers found: 10.

 Photos from the George Grantham Bain Collection at the Library of Congress.