For single seasons, From 1947 to 2008, From Age 10 to 20, Throws LH, (requiring ERAp≥90, GS≥10, and At least 75 Innings Pitched), sorted by greatest ERAp

Player ages are computed as their age on June 30th

  Cnt Player            **ERA **  GS   IP  Year Age Tm  Lg  G  CG SHO GF  W  L  W-L% SV  H   R   ER  BB  SO   ERA  HR  BF   AB  2B 3B IBB HBP  SH  SF GDP  SB CS Pk BK WP   BA   OBP   SLG   OPS  OPS   Pit  Str
 ----+-----------------+--------+---+-----+----+---+---+--+---+--+---+--+--+--+-----+--+---+---+---+---+---+------+--+----+----+--+--+---+---+---+---+---+---+--+--+--+--+-----+-----+-----+-----+----+----+---- 
    1 Fernando Valenzue    135    25 192.1 1981  20 LAD NL  25 11   8  0 13  7  .650  0 140  55  53  61 180   2.48 11  758  684 12  3   4   1   9   3  11  25 10  3  0  4  .205  .270  .279  .549   62           
    2 Rick Ankiel          134    30 175   2000  20 STL NL  31  0   0  0 11  7  .611  0 137  80  68  90 194   3.50 21  735  625 26  1   2   6   8   6  15   9  7  1  2 12  .219  .320  .365  .685   76 3078 1851 
    3 Chet Nichols         128    19 156   1951  20 BSN NL  33 12   3  6 11  8  .579  2 142  61  50  69  71   2.88  4  663                  1                        0  8                            0           
    4 Don Gullett          123    31 217.2 1971  20 CIN NL  35  4   3  0 16  6  .727  0 196  73  64  64 107   2.65 14  891  810 37  1   6   2  13   2  25   2  3  0  0  3  .242  .298  .342  .640   88           
    5 Ray Sadecki          119    31 222.2 1961  20 STL NL  31 13   0  0 14 10  .583  0 196 100  92 102 114   3.72 28  949  824 44  5   2   3  11   9  18   6  5  1  0  8  .238  .321  .405  .726   89           
    6 Frank Tanana         109    35 268.2 1974  20 CAL AL  39 12   4  2 14 19  .424  0 262 104  93  77 180   3.12 27 1127 1028 41  3   4   8  10   4  25  15 13  3  2  4  .255  .311  .379  .690  103           
    7 Ray Sadecki          109    26 157.1 1960  19 STL NL  26  7   1  0  9  9  .500  0 148  76  66  86  95   3.78 15  690  593 19  5   1   1   3   6  21   5  1  1  0  8  .250  .343  .374  .717   97           
    8 Chuck Stobbs         108    19 152   1949  19 BOS AL  26 10   0  2 11  6  .647  0 145  72  68  75  70   4.03 10  653                  2                        1  1                            0           
    9 Mickey McDermott     108    12  80   1949  20 BOS AL  12  6   2  0  5  4  .556  0  63  37  36  52  50   4.05  5  349                  3                        0  2                            0           
   10 Oliver Perez         107    15  90   2002  20 SDP NL  16  0   0  0  4  5  .444  0  71  37  35  48  94   3.50 13  387  326  9  2   1   5   5   3   8   1  1  0  0  3  .218  .325  .377  .702   97 1513  921 
   11 Johnny Antonelli     107    10  96   1949  19 BSN NL  22  3   1  6  3  7  .300  0  99  49  38  42  48   3.56  6  416                  2                        0  3                            0           
   12 C.C. Sabathia        102    33 180.1 2001  20 CLE AL  33  0   0  0 17  5  .773  0 149  93  88  95 171   4.39 19  763  653 32  2   1   7   3   5   8  27 15  4  3  7  .228  .330  .371  .701   85 3132 1894 
   13 Johnny Podres        101    18 115   1953  20 BRO NL  33  3   1  3  9  4  .692  0 126  62  54  64  82   4.23 12  518                  1                        0  2                            0           
   14 Dick Ellsworth       101    27 176.2 1960  20 CHC NL  31  6   0  0  7 13  .350  0 170  83  73  72  94   3.72 12  744  661 28 10   8   2   3   5  22   9  6  2  0  1  .257  .330  .384  .714  103           
   15 Clayton Kershaw      100    21 107.2 2008  20 LAD NL  22  0   0  0  5  5  .500  0 109  51  51  52 100   4.26 11  470  411 22  2   3   1   3   3  12   5  2  2  0  7  .265  .347  .409  .756  103 1859 1130 
   16 Ken Holtzman          97    33 220.2 1966  20 CHC NL  34  9   0  0 11 16  .407  0 194 104  93  68 171   3.79 27  912  827 37  9   6   4   9   4  12   7 10  1  1  8  .235  .295  .399  .694   96           
   17 Chuck Stobbs          96    21 169.1 1950  20 BOS AL  32  6   0  3 12  7  .632  1 158 104  96  88  78   5.10 17  738                  5                        1  0                            0           
   18 Mike McCormick        95    31 225.2 1959  20 SFG NL  47  7   3  9 12 16  .429  4 213 117 100  86 151   3.99 24  972  859 30  8  13   1  18   7  18   8  3  3  0  9  .248  .315  .385  .700   93           
   19 Kevin Kobel           90    24 169.1 1974  20 MIL AL  34  3   2  3  6 14  .300  0 166  84  75  54  74   3.99 16  712  644 29  3   1   2   6   6  14   8  7  5  0  3  .258  .314  .387  .701  102           

Seasons/Careers found: 19.

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