Single Season ERA - minimum 150 innings
| Rank | Player | Year | Team | W | L | W-L% | ERA | G | GS | GF | CG | SH | SV | SV% | IP | BB | SO | WHIP | BR9 | HR9 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Pedro Martinez | 1997 | SPS | 21 | 5 | .808 | 1.87 | 36 | 36 | 0 | 3 | 2 | 0 | 0 | 241 | 63 | 305 | 0.876 | 7.88 | 0.93 |
| 2 | Kevin Brown | 1997 | HRH | 17 | 6 | .739 | 1.94 | 34 | 34 | 0 | 4 | 2 | 0 | 0 | 236.1 | 82 | 187 | 1.058 | 9.52 | 0.30 |
| 3 | Sonny Gray | 2015 | IMG | 16 | 7 | .696 | 2.10 | 30 | 30 | 0 | 0 | 0 | 0 | 0 | 206 | 49 | 152 | 0.879 | 7.91 | 0.66 |
| 4 | Roger Clemens | 1997 | MNL | 16 | 12 | .571 | 2.11 | 35 | 35 | 0 | 9 | 2 | 0 | 0 | 269.1 | 83 | 283 | 1.073 | 9.66 | 0.67 |
| 5 | Billy Pierce | 1949 | PBP | 16 | 4 | .800 | 2.17 | 75 | 15 | 60 | 1 | 0 | 2 | 40 | 182.2 | 121 | 102 | 1.363 | 12.27 | 0.30 |
| 6 | Wilcy Moore | 1927 | MIT | 22 | 6 | .786 | 2.19 | 78 | 5 | 73 | 1 | 0 | 13 | 52 | 201.2 | 57 | 75 | 1.250 | 11.25 | 0.13 |
| 7 | Jon Matlack | 1974 | IMG | 12 | 9 | .571 | 2.30 | 25 | 25 | 0 | 9 | 2 | 0 | 0 | 195.1 | 56 | 142 | 1.080 | 9.72 | 0.28 |
| 8 | Zack Greinke | 2015 | MNL | 18 | 7 | .720 | 2.30 | 29 | 29 | 0 | 6 | 1 | 0 | 0 | 222.2 | 49 | 182 | 0.862 | 7.76 | 0.73 |
| 9 | Max Manning | 1949 | THD | 17 | 6 | .739 | 2.35 | 55 | 18 | 37 | 4 | 1 | 2 | 22 | 206.2 | 57 | 45 | 1.108 | 9.97 | 0.74 |
| 10 | Jake Arrieta | 2015 | BRI | 14 | 13 | .519 | 2.43 | 31 | 31 | 0 | 5 | 3 | 0 | 0 | 229.1 | 59 | 224 | 0.977 | 8.79 | 0.63 |
| 11 | Bert Blyleven | 1974 | GTL | 13 | 8 | .619 | 2.45 | 27 | 27 | 0 | 13 | 1 | 0 | 0 | 213.1 | 65 | 200 | 1.144 | 10.29 | 0.38 |
| 12 | Jacob Degrom | 2015 | IMG | 10 | 3 | .769 | 2.45 | 26 | 26 | 0 | 1 | 1 | 0 | 0 | 176.1 | 43 | 182 | 0.953 | 8.57 | 0.97 |
| 13 | Jim Archer | 1961 | PBP | 15 | 9 | .625 | 2.49 | 38 | 25 | 13 | 4 | 1 | 1 | 50 | 195.1 | 59 | 108 | 1.280 | 11.52 | 0.37 |
| 14 | Guy Bush | 1927 | IMG | 15 | 8 | .652 | 2.51 | 37 | 23 | 14 | 2 | 0 | 4 | 100 | 190 | 71 | 76 | 1.137 | 10.23 | 0.14 |
| 15 | Phil Niekro | 1974 | CIR | 15 | 6 | .714 | 2.58 | 28 | 28 | 0 | 14 | 7 | 0 | 0 | 227 | 83 | 152 | 1.106 | 9.95 | 0.48 |
| 16 | Hector Santiago | 2015 | GTL | 12 | 7 | .632 | 2.59 | 28 | 28 | 0 | 2 | 1 | 0 | 0 | 180.2 | 64 | 151 | 1.024 | 9.22 | 0.95 |
| 17 | Dick Donovan | 1961 | MNL | 11 | 6 | .647 | 2.60 | 23 | 23 | 0 | 7 | 2 | 0 | 0 | 169.1 | 26 | 70 | 0.980 | 8.82 | 1.01 |
| 18 | Jerry Koosman | 1977 | MNL | 16 | 10 | .615 | 2.62 | 30 | 30 | 0 | 8 | 2 | 0 | 0 | 227 | 69 | 190 | 1.167 | 10.51 | 0.95 |
| 19 | Mike Scott | 1987 | QBS | 16 | 7 | .696 | 2.62 | 32 | 32 | 0 | 6 | 0 | 0 | 0 | 230.1 | 74 | 206 | 1.059 | 9.53 | 0.78 |
| 20 | John Smoltz | 1997 | IMG | 19 | 6 | .760 | 2.62 | 33 | 33 | 0 | 5 | 1 | 0 | 0 | 247.1 | 55 | 249 | 1.108 | 9.97 | 0.84 |
| 21 | Burleigh Grimes | 1927 | SSL | 16 | 16 | .500 | 2.65 | 46 | 32 | 14 | 5 | 2 | 0 | 0 | 258 | 94 | 115 | 1.291 | 11.62 | 0.42 |
| 22 | Jim Perry | 1974 | GTL | 7 | 12 | .368 | 2.68 | 26 | 26 | 0 | 8 | 1 | 0 | 0 | 191.1 | 48 | 60 | 1.265 | 11.38 | 0.38 |
| 23 | Bill Werle | 1949 | COL | 11 | 6 | .647 | 2.71 | 54 | 27 | 27 | 0 | 0 | 1 | 33 | 172.2 | 47 | 87 | 1.112 | 10.01 | 0.47 |
| 24 | Vic Aldridge | 1927 | CIR | 16 | 11 | .593 | 2.71 | 36 | 34 | 2 | 8 | 3 | 0 | 0 | 245.1 | 96 | 107 | 1.333 | 12.00 | 0.55 |
| 25 | Harry Salmon | 1927 | MIT | 16 | 10 | .615 | 2.75 | 79 | 17 | 62 | 11 | 1 | 7 | 78 | 281 | 63 | 108 | 1.125 | 10.12 | 0.54 |
| 26 | Scott Erickson | 1997 | IMG | 15 | 5 | .750 | 2.79 | 32 | 32 | 0 | 1 | 1 | 0 | 0 | 222.1 | 56 | 126 | 1.088 | 9.80 | 0.81 |
| 27 | Tommy Thomas | 1927 | THD | 24 | 9 | .727 | 2.82 | 41 | 41 | 0 | 15 | 4 | 0 | 0 | 319.2 | 119 | 117 | 1.233 | 11.09 | 0.39 |
| 28 | Jim Kaat | 1974 | IMG | 10 | 6 | .625 | 2.82 | 25 | 25 | 0 | 4 | 2 | 0 | 0 | 179 | 47 | 76 | 1.067 | 9.60 | 0.50 |
| 29 | Frank Lary | 1961 | SUS | 12 | 15 | .444 | 2.82 | 30 | 29 | 1 | 9 | 5 | 0 | 0 | 214 | 61 | 107 | 1.131 | 10.18 | 0.46 |
| 30 | Gready McKinnis | 1949 | SSL | 11 | 15 | .423 | 2.83 | 32 | 32 | 0 | 9 | 0 | 0 | 0 | 229 | 75 | 103 | 1.162 | 10.45 | 0.51 |
| 31 | Dennis Leonard | 1977 | MIT | 17 | 13 | .567 | 2.83 | 59 | 27 | 32 | 6 | 0 | 6 | 60 | 260.2 | 87 | 221 | 1.162 | 10.46 | 0.79 |
| 32 | Don Sutton | 1987 | QBS | 10 | 8 | .556 | 2.83 | 27 | 27 | 0 | 1 | 0 | 0 | 0 | 168.1 | 49 | 96 | 1.212 | 10.91 | 0.96 |
| 33 | Greg Maddux | 1997 | HRH | 17 | 7 | .708 | 2.87 | 34 | 34 | 0 | 0 | 0 | 0 | 0 | 226 | 48 | 153 | 1.066 | 9.60 | 0.80 |
| 34 | David Price | 2015 | PVD | 9 | 14 | .391 | 2.87 | 32 | 32 | 0 | 1 | 0 | 0 | 0 | 213 | 42 | 214 | 1.169 | 10.52 | 0.46 |
| 35 | Clifford Carter | 1927 | MIT | 13 | 13 | .500 | 2.88 | 36 | 35 | 1 | 2 | 1 | 0 | 0 | 212.2 | 69 | 46 | 1.227 | 11.05 | 0.63 |
| 36 | Ismael Valdes | 1997 | SSL | 9 | 7 | .562 | 2.89 | 29 | 28 | 1 | 1 | 0 | 0 | 0 | 186.2 | 65 | 111 | 1.200 | 10.80 | 1.06 |
| 37 | Clayton Kershaw | 2015 | QCK | 18 | 7 | .720 | 2.91 | 34 | 33 | 1 | 6 | 3 | 0 | 0 | 231.2 | 52 | 293 | 1.019 | 9.17 | 0.89 |
| 38 | Jack Quinn | 1927 | TBK | 8 | 14 | .364 | 2.93 | 30 | 26 | 4 | 7 | 2 | 0 | 0 | 193.1 | 62 | 48 | 1.407 | 12.66 | 0.37 |
| 39 | Carmen Hill | 1927 | SSL | 19 | 11 | .633 | 2.94 | 49 | 31 | 18 | 13 | 2 | 1 | 100 | 294.1 | 107 | 98 | 1.284 | 11.56 | 0.40 |
| 40 | Dolf Luque | 1927 | MNL | 16 | 8 | .667 | 2.96 | 32 | 28 | 4 | 6 | 1 | 0 | 0 | 224.2 | 53 | 72 | 1.255 | 11.30 | 0.40 |
| 41 | Dave Freisleben | 1974 | SEP | 10 | 4 | .714 | 2.97 | 25 | 25 | 0 | 4 | 2 | 0 | 0 | 163.2 | 72 | 115 | 1.265 | 11.38 | 0.49 |
| 42 | Lefty Grove | 1927 | SRR | 14 | 16 | .467 | 2.99 | 73 | 26 | 47 | 5 | 2 | 4 | 50 | 274.1 | 128 | 184 | 1.436 | 12.93 | 0.20 |
| 43 | Charlie Root | 1927 | GTL | 19 | 13 | .594 | 2.99 | 40 | 39 | 1 | 19 | 3 | 0 | 0 | 322.1 | 131 | 146 | 1.198 | 10.78 | 0.53 |
| 44 | Frank Tanana | 1977 | MWB | 17 | 7 | .708 | 3.00 | 35 | 35 | 0 | 6 | 1 | 0 | 0 | 237.1 | 67 | 211 | 1.108 | 9.97 | 0.68 |
| 45 | Corner Pocket Yokely | 1927 | TLF | 18 | 11 | .621 | 3.00 | 34 | 34 | 0 | 8 | 4 | 0 | 0 | 246.1 | 86 | 71 | 1.100 | 9.90 | 0.40 |
| 46 | Oscar Levis | 1927 | DIN | 14 | 7 | .667 | 3.00 | 27 | 27 | 0 | 8 | 3 | 0 | 0 | 204 | 52 | 40 | 1.123 | 10.10 | 0.62 |
| 47 | Jesse Petty | 1927 | GTL | 16 | 18 | .471 | 3.02 | 40 | 36 | 4 | 14 | 1 | 0 | 0 | 283.1 | 74 | 103 | 1.214 | 10.93 | 0.29 |
| 48 | Jon Lieber | 1997 | DIN | 12 | 9 | .571 | 3.03 | 29 | 29 | 0 | 0 | 0 | 0 | 0 | 181.1 | 38 | 152 | 1.169 | 10.52 | 0.94 |
| 49 | Joe Niekro | 1977 | THD | 12 | 5 | .706 | 3.03 | 30 | 29 | 1 | 0 | 0 | 0 | 0 | 181 | 75 | 95 | 1.293 | 11.64 | 0.90 |
| 50 | Bob Lemon | 1949 | SPS | 25 | 12 | .676 | 3.04 | 42 | 40 | 2 | 12 | 3 | 0 | 0 | 308.1 | 155 | 167 | 1.242 | 11.18 | 0.90 |
| 51 | George Pipgras | 1927 | BUM | 10 | 9 | .526 | 3.04 | 35 | 31 | 4 | 1 | 0 | 0 | 0 | 168.2 | 85 | 83 | 1.429 | 12.86 | 0.16 |
| 52 | Park Chan Ho | 1997 | MNL | 12 | 8 | .600 | 3.04 | 33 | 29 | 4 | 2 | 1 | 0 | 0 | 192.1 | 73 | 149 | 1.165 | 10.48 | 1.22 |
| 53 | Alan Benes | 1997 | SPS | 12 | 9 | .571 | 3.06 | 26 | 26 | 0 | 2 | 1 | 0 | 0 | 162 | 80 | 169 | 1.191 | 10.72 | 0.72 |
| 54 | Potato Piloto | 1949 | DIN | 9 | 4 | .692 | 3.06 | 86 | 5 | 81 | 0 | 0 | 8 | 73 | 153 | 56 | 50 | 1.268 | 11.41 | 0.59 |
| 55 | Andy Benes | 1997 | SSL | 12 | 5 | .706 | 3.06 | 26 | 26 | 0 | 0 | 0 | 0 | 0 | 164.2 | 73 | 157 | 1.263 | 11.37 | 0.66 |
| 56 | Buzz Capra | 1974 | CIR | 10 | 7 | .588 | 3.06 | 25 | 25 | 0 | 3 | 0 | 0 | 0 | 179.1 | 84 | 110 | 1.255 | 11.29 | 0.70 |
| 57 | Dazzy Vance | 1927 | MNL | 10 | 20 | .333 | 3.07 | 39 | 34 | 5 | 13 | 3 | 0 | 0 | 272.2 | 77 | 175 | 1.133 | 10.20 | 0.40 |
| 58 | Andy Cooper | 1927 | TBK | 10 | 7 | .588 | 3.07 | 29 | 18 | 11 | 8 | 3 | 1 | 100 | 155.1 | 14 | 44 | 1.120 | 10.08 | 0.52 |
| 59 | Howie Fox | 1949 | DIN | 15 | 9 | .625 | 3.08 | 44 | 33 | 11 | 1 | 0 | 0 | 0 | 239.2 | 81 | 82 | 1.218 | 10.97 | 0.64 |
| 60 | Waite Hoyt | 1927 | BRI | 15 | 13 | .536 | 3.08 | 34 | 34 | 0 | 13 | 2 | 0 | 0 | 257 | 55 | 112 | 1.183 | 10.65 | 0.53 |
| 61 | Tom Griffin | 1974 | CIR | 10 | 9 | .526 | 3.09 | 26 | 26 | 0 | 3 | 2 | 0 | 0 | 180.2 | 70 | 82 | 1.306 | 11.76 | 0.50 |
| 62 | Mountain Drop Mitchell | 1927 | MNL | 10 | 5 | .667 | 3.09 | 34 | 18 | 16 | 6 | 1 | 2 | 40 | 166 | 59 | 35 | 1.349 | 12.14 | 0.27 |
| 63 | Brad Radke | 1997 | GTL | 15 | 9 | .625 | 3.10 | 32 | 32 | 0 | 7 | 1 | 0 | 0 | 235.1 | 58 | 157 | 1.045 | 9.41 | 0.84 |
| 64 | Dave Koslo | 1949 | COL | 14 | 8 | .636 | 3.10 | 92 | 6 | 86 | 0 | 0 | 20 | 83 | 209 | 71 | 77 | 1.129 | 10.16 | 0.69 |
| 65 | Nolan Ryan | 1987 | MNL | 13 | 10 | .565 | 3.11 | 27 | 27 | 0 | 4 | 0 | 0 | 0 | 194 | 78 | 233 | 1.129 | 10.16 | 0.84 |
| 66 | Mike Garcia | 1949 | IMG | 11 | 11 | .500 | 3.11 | 52 | 13 | 39 | 4 | 2 | 13 | 72 | 165 | 58 | 93 | 1.224 | 11.02 | 0.49 |
| 67 | Brett Anderson | 2015 | SRR | 12 | 5 | .706 | 3.12 | 30 | 30 | 0 | 0 | 0 | 0 | 0 | 161.2 | 66 | 105 | 1.410 | 12.69 | 0.89 |
| 68 | Cole Hamels | 2015 | QCK | 12 | 11 | .522 | 3.12 | 33 | 33 | 0 | 4 | 3 | 0 | 0 | 210.1 | 74 | 189 | 1.174 | 10.57 | 0.94 |
| 69 | Don Sutton | 1974 | TLF | 6 | 8 | .429 | 3.13 | 24 | 23 | 1 | 0 | 0 | 0 | 0 | 149.2 | 39 | 93 | 1.183 | 10.64 | 1.14 |
| 70 | Red Lucas | 1927 | COL | 17 | 9 | .654 | 3.14 | 35 | 33 | 2 | 8 | 0 | 0 | 0 | 252 | 58 | 67 | 1.131 | 10.18 | 0.32 |
| 71 | Tom Glavine | 1997 | SRR | 14 | 8 | .636 | 3.15 | 34 | 34 | 0 | 1 | 0 | 0 | 0 | 234.1 | 80 | 146 | 1.208 | 10.87 | 0.73 |
| 72 | Pete Alexander | 1927 | MNL | 18 | 12 | .600 | 3.15 | 35 | 34 | 1 | 15 | 3 | 0 | 0 | 274 | 51 | 66 | 1.226 | 11.04 | 0.36 |
| 73 | Corey Kluber | 2015 | CIR | 18 | 7 | .720 | 3.16 | 32 | 32 | 0 | 2 | 2 | 0 | 0 | 216.2 | 74 | 236 | 1.195 | 10.76 | 1.12 |
| 74 | Dutch Ulrich | 1927 | DIN | 14 | 8 | .636 | 3.19 | 30 | 28 | 2 | 3 | 0 | 0 | 0 | 203 | 55 | 52 | 1.330 | 11.97 | 0.49 |
| 75 | Carlos Martinez | 2015 | SSL | 11 | 5 | .688 | 3.21 | 34 | 28 | 6 | 0 | 0 | 0 | 0 | 174 | 72 | 146 | 1.345 | 12.10 | 1.09 |
| 76 | Fergie Jenkins | 1974 | BRI | 12 | 9 | .571 | 3.21 | 23 | 23 | 0 | 10 | 0 | 0 | 0 | 185 | 33 | 115 | 1.086 | 9.78 | 1.17 |
| 77 | Ray Kremer | 1927 | TBK | 11 | 12 | .478 | 3.21 | 34 | 29 | 5 | 11 | 4 | 2 | 100 | 229.2 | 66 | 67 | 1.271 | 11.44 | 0.31 |
| 78 | Jack Sanford | 1961 | PBP | 14 | 7 | .667 | 3.22 | 38 | 27 | 11 | 6 | 1 | 0 | 0 | 204 | 95 | 106 | 1.299 | 11.69 | 0.97 |
| 79 | Gene Richardson | 1949 | GTL | 15 | 10 | .600 | 3.23 | 35 | 35 | 0 | 7 | 4 | 0 | 0 | 253.2 | 109 | 136 | 1.329 | 11.96 | 0.53 |
| 80 | Tommy John | 1977 | MWB | 18 | 9 | .667 | 3.24 | 38 | 38 | 0 | 1 | 0 | 0 | 0 | 219.2 | 61 | 132 | 1.256 | 11.31 | 0.98 |
| 81 | Nolan Ryan | 1977 | SRR | 16 | 16 | .500 | 3.26 | 37 | 37 | 0 | 10 | 0 | 0 | 0 | 268 | 206 | 298 | 1.474 | 13.26 | 0.47 |
| 82 | Phil Cockrell | 1927 | SSL | 14 | 11 | .560 | 3.26 | 30 | 30 | 0 | 7 | 4 | 0 | 0 | 221 | 70 | 44 | 1.167 | 10.51 | 0.69 |
| 83 | Michael Fiers | 2015 | QCK | 10 | 11 | .476 | 3.26 | 29 | 29 | 0 | 0 | 0 | 0 | 0 | 179.1 | 68 | 178 | 1.188 | 10.69 | 1.05 |
| 84 | Steve Rogers | 1977 | COL | 21 | 9 | .700 | 3.27 | 37 | 37 | 0 | 9 | 2 | 0 | 0 | 275.1 | 92 | 203 | 1.271 | 11.44 | 0.78 |
| 85 | Hank Miller | 1949 | TLF | 13 | 10 | .565 | 3.27 | 30 | 30 | 0 | 5 | 1 | 0 | 0 | 217.1 | 102 | 99 | 1.385 | 12.46 | 0.50 |
| 86 | Jim Rooker | 1974 | GRR | 11 | 11 | .500 | 3.30 | 29 | 29 | 0 | 6 | 1 | 0 | 0 | 210 | 95 | 121 | 1.362 | 12.26 | 0.69 |
| 87 | Doc Medich | 1974 | GRR | 12 | 9 | .571 | 3.31 | 29 | 27 | 2 | 2 | 0 | 0 | 0 | 174 | 91 | 98 | 1.580 | 14.22 | 0.78 |
| 88 | Glen Hobbie | 1961 | PBP | 12 | 6 | .667 | 3.31 | 34 | 26 | 8 | 3 | 1 | 2 | 67 | 184.2 | 50 | 94 | 1.256 | 11.31 | 1.12 |
| 89 | Bullet Joe Rogan | 1927 | BRI | 6 | 12 | .333 | 3.32 | 42 | 18 | 24 | 3 | 0 | 6 | 75 | 176 | 47 | 90 | 1.188 | 10.69 | 0.41 |
| 90 | Bill Wegman | 1987 | QBS | 10 | 11 | .476 | 3.34 | 31 | 31 | 0 | 4 | 0 | 0 | 0 | 210 | 53 | 91 | 1.262 | 11.36 | 0.94 |
| 91 | Mel Parnell | 1949 | BRI | 20 | 17 | .541 | 3.35 | 40 | 40 | 0 | 18 | 5 | 0 | 0 | 322.1 | 134 | 133 | 1.350 | 12.15 | 0.47 |
| 92 | Chris Sale | 2015 | SPS | 11 | 12 | .478 | 3.36 | 33 | 33 | 0 | 0 | 0 | 0 | 0 | 198.1 | 59 | 288 | 1.210 | 10.89 | 0.95 |
| 93 | Jesse Haines | 1927 | IMG | 16 | 19 | .457 | 3.36 | 49 | 36 | 13 | 14 | 1 | 4 | 67 | 297.1 | 92 | 92 | 1.291 | 11.62 | 0.39 |
| 94 | Bert Blyleven | 1977 | MIT | 15 | 12 | .556 | 3.37 | 36 | 36 | 0 | 5 | 1 | 0 | 0 | 235 | 96 | 207 | 1.230 | 11.07 | 1.30 |
| 95 | Dolly Cooper | 1927 | DIN | 18 | 6 | .750 | 3.38 | 27 | 27 | 0 | 5 | 0 | 0 | 0 | 200 | 45 | 32 | 1.240 | 11.16 | 0.41 |
| 96 | Jim Palmer | 1977 | IMG | 16 | 14 | .533 | 3.38 | 38 | 38 | 0 | 6 | 0 | 0 | 0 | 288 | 107 | 205 | 1.205 | 10.84 | 0.97 |
| 97 | Michael Wacha | 2015 | DIN | 8 | 9 | .471 | 3.38 | 30 | 30 | 0 | 0 | 0 | 0 | 0 | 178.1 | 52 | 130 | 1.183 | 10.65 | 0.71 |
| 98 | Gaylord Perry | 1974 | BBC | 20 | 7 | .741 | 3.40 | 35 | 35 | 0 | 11 | 3 | 0 | 0 | 270.1 | 96 | 187 | 1.158 | 10.42 | 0.87 |
| 99 | Freddie Fitzsimmons | 1927 | PBP | 11 | 11 | .500 | 3.40 | 51 | 27 | 24 | 4 | 1 | 8 | 67 | 230.1 | 78 | 81 | 1.520 | 13.68 | 0.27 |
| 100 | Andy Messersmith | 1974 | DSP | 12 | 11 | .522 | 3.40 | 27 | 27 | 0 | 8 | 1 | 0 | 0 | 198.1 | 70 | 147 | 1.175 | 10.57 | 1.00 |