24 pitchers are tied for the best K/9 by a starting pitcher in a season, with 27.00 per nine innings. The first three are Johan Oviedo and Austin Cox this season and Dan Altavilla in 2024.
| NAME | K/9 | SEASON | TM | G | W | L | W% | GS | ERA | SO | CG | SHO | SV | IP | H | ER | R | HR | BB | HBP | GF | IBB | TBF | WP | BB/9 | K/BB | HR/9 | K% | BB% | WHIP | BABIP | RA | H/9 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 |  | J. Oviedo | 27.00 | 2025 |  PIT | 1 | 0 | 0 | 1 | 18.00 | 3 | 0 | 0 | 0 | 1.0 | 2 | 2 | 2 | 0 | 3 | 0 | 0 | 0 | 8 | 0 | 27.00 | 1.00 | 0.00 | 37.5 | 37.5 | 5.00 | 1.000 | 18.00 | 18.00 | |
| 2 | | A. Cox | 27.00 | 2025 |  ATL | 1 | 0 | 0 | 1 | 27.00 | 1 | 0 | 0 | 0 | 0.1 | 3 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 4 | 0 | 0.00 | 0.00 | 25.0 | 0.0 | 9.00 | 1.000 | 27.00 | 81.00 | ||
| 3 | | D. Altavilla | 27.00 | 2024 |  KCR | 1 | 0 | 1 | .000 | 1 | 135.00 | 1 | 0 | 0 | 0 | 0.1 | 3 | 5 | 5 | 0 | 2 | 0 | 0 | 0 | 6 | 0 | 54.00 | 0.50 | 0.00 | 16.7 | 33.3 | 15.00 | 1.000 | 135.00 | 81.00 |
| 4 | | S. Moll | 27.00 | 2023 |  OAK | 1 | 0 | 0 | 1 | 0.00 | 3 | 0 | 0 | 0 | 1.0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 4 | 0 | 0.00 | 0.00 | 75.0 | 0.0 | 1.00 | 1.000 | 0.00 | 9.00 | ||
| 5 | | C. Ferguson | 27.00 | 2022 |  LAD | 1 | 0 | 0 | 1 | 0.00 | 3 | 0 | 0 | 0 | 1.0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 3 | 0 | 0.00 | 0.00 | 100.0 | 0.0 | 0.00 | 0.00 | 0.00 | |||
| 6 | | D. Moreta | 27.00 | 2022 |  CIN | 1 | 0 | 1 | .000 | 1 | 54.00 | 1 | 0 | 0 | 0 | 0.1 | 2 | 2 | 2 | 1 | 0 | 0 | 0 | 0 | 3 | 0 | 0.00 | 27.00 | 33.3 | 0.0 | 6.00 | 1.000 | 54.00 | 54.00 | |
| 7 | | S. Howard | 27.00 | 2021 | PIT | 1 | 0 | 0 | 1 | 0.00 | 3 | 0 | 0 | 0 | 1.0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 3 | 0 | 0.00 | 0.00 | 100.0 | 0.0 | 0.00 | 0.00 | 0.00 | |||
| 8 | | J. Jackson | 27.00 | 2021 |  SFG | 1 | 0 | 1 | .000 | 1 | 81.00 | 1 | 0 | 0 | 0 | 0.1 | 1 | 3 | 3 | 1 | 2 | 0 | 0 | 0 | 4 | 0 | 54.00 | 0.50 | 27.00 | 25.0 | 50.0 | 9.00 | 81.00 | 27.00 | |
| 9 |  | C. Sánchez | 27.00 | 2021 |  PHI | 1 | 0 | 0 | 1 | 108.00 | 1 | 0 | 0 | 0 | 0.1 | 3 | 4 | 4 | 0 | 1 | 0 | 0 | 0 | 5 | 0 | 27.00 | 1.00 | 0.00 | 20.0 | 20.0 | 12.00 | 1.000 | 108.00 | 81.00 | |
| 10 |  | N. Cortes | 27.00 | 2020 |  SEA | 1 | 0 | 1 | .000 | 1 | 189.00 | 1 | 0 | 0 | 0 | 0.1 | 5 | 7 | 8 | 2 | 2 | 0 | 0 | 0 | 9 | 0 | 54.00 | 0.50 | 54.00 | 11.1 | 22.2 | 21.00 | .750 | 216.00 | 135.00 |
| 11 | | A. Brice | 27.00 | 2020 |  BOS | 1 | 0 | 0 | 1 | 0.00 | 3 | 0 | 0 | 0 | 1.0 | 0 | 0 | 0 | 0 | 2 | 0 | 0 | 0 | 6 | 0 | 18.00 | 1.50 | 0.00 | 50.0 | 33.3 | 2.00 | .000 | 0.00 | 0.00 | |
| 12 | | J. Barnes | 27.00 | 2019 |  MIL | 1 | 0 | 0 | 1 | 27.00 | 3 | 0 | 0 | 0 | 1.0 | 2 | 3 | 3 | 1 | 3 | 0 | 0 | 0 | 8 | 1 | 27.00 | 1.00 | 9.00 | 37.5 | 37.5 | 5.00 | 1.000 | 27.00 | 18.00 | |
| 13 | | J. Schultz | 27.00 | 2018 |  TBR | 1 | 0 | 1 | .000 | 1 | 54.00 | 2 | 0 | 0 | 0 | 0.2 | 2 | 4 | 4 | 1 | 2 | 0 | 0 | 0 | 6 | 1 | 27.00 | 1.00 | 13.50 | 33.3 | 33.3 | 6.00 | 1.000 | 54.00 | 27.00 |
| 14 | | J. Venters | 27.00 | 2018 | TBR | 1 | 0 | 1 | .000 | 1 | 135.00 | 1 | 0 | 0 | 0 | 0.1 | 3 | 5 | 5 | 0 | 2 | 0 | 0 | 0 | 6 | 0 | 54.00 | 0.50 | 0.00 | 16.7 | 33.3 | 15.00 | 1.000 | 135.00 | 81.00 |
| 15 | | M. Mulder | 27.00 | 2008 |  STL | 1 | 0 | 0 | 1 | 0.00 | 1 | 0 | 0 | 0 | 0.1 | 0 | 0 | 0 | 0 | 2 | 0 | 0 | 0 | 3 | 0 | 54.00 | 0.50 | 0.00 | 33.3 | 66.7 | 6.00 | 0.00 | 0.00 | ||
| 16 |  | N. Ryan | 27.00 | 1966 |  NYM | 1 | 0 | 1 | .000 | 1 | 36.00 | 3 | 0 | 0 | 0 | 1.0 | 4 | 4 | 4 | 0 | 2 | 0 | 0 | 1 | 9 | 1 | 18.00 | 1.50 | 0.00 | 33.3 | 22.2 | 6.00 | 1.000 | 36.00 | 36.00 |
| 17 | | C. McLish | 27.00 | 1964 | PHI | 1 | 0 | 1 | .000 | 1 | 54.00 | 1 | 0 | 0 | 0 | 0.1 | 2 | 2 | 2 | 0 | 0 | 0 | 0 | 0 | 3 | 0 | 0.00 | 0.00 | 33.3 | 0.0 | 6.00 | 1.000 | 54.00 | 54.00 | |
| 18 | | P. Lovrich | 27.00 | 1963 |  KCA | 1 | 0 | 1 | .000 | 1 | 108.00 | 1 | 0 | 0 | 0 | 0.1 | 5 | 4 | 4 | 0 | 1 | 0 | 0 | 1 | 7 | 0 | 27.00 | 1.00 | 0.00 | 14.3 | 14.3 | 18.00 | 1.000 | 108.00 | 135.00 |
| 19 | | A. Kellner | 27.00 | 1948 |  PHA | 1 | 0 | 0 | 1 | 54.00 | 1 | 0 | 0 | 0 | 0.1 | 1 | 2 | 2 | 0 | 3 | 0 | 0 | 5 | 1 | 81.00 | 0.33 | 0.00 | 20.0 | 60.0 | 12.00 | 1.000 | 54.00 | 27.00 | ||
| 20 | | T. Byrne | 27.00 | 1946 |  NYY | 1 | 0 | 1 | .000 | 1 | 81.00 | 1 | 0 | 0 | 0 | 0.1 | 1 | 3 | 5 | 0 | 3 | 0 | 0 | 6 | 0 | 81.00 | 0.33 | 0.00 | 16.7 | 50.0 | 12.00 | .500 | 135.00 | 27.00 | |
| 21 | | F. Wurm | 27.00 | 1944 |  BKN | 1 | 0 | 0 | 1 | 108.00 | 1 | 0 | 0 | 0 | 0.1 | 1 | 4 | 4 | 0 | 5 | 0 | 0 | 7 | 0 | 135.00 | 0.20 | 0.00 | 14.3 | 71.4 | 18.00 | 1.000 | 108.00 | 27.00 | ||
| 22 | | G. Braxton | 27.00 | 1933 |  SLA | 1 | 0 | 1 | .000 | 1 | 108.00 | 1 | 0 | 0 | 0 | 0.1 | 2 | 4 | 5 | 0 | 2 | 1 | 0 | 7 | 0 | 54.00 | 0.50 | 0.00 | 14.3 | 28.6 | 12.00 | .667 | 135.00 | 54.00 | |
| 23 | | W. Leverenz | 27.00 | 1915 | SLA | 1 | 0 | 1 | .000 | 1 | 108.00 | 1 | 0 | 0 | 0 | 0.1 | 3 | 4 | 4 | 0 | 1 | 0 | 0 | 5 | 0 | 27.00 | 1.00 | 0.00 | 20.0 | 20.0 | 12.00 | 1.000 | 108.00 | 81.00 | |
| 24 | | C. Hageman | 27.00 | 1912 | BSA | 1 | 0 | 0 | 1 | 1 | 0 | 0 | 0 | 0.1 | 2 | 2 | 0 | 3 | 0 | 0 | 6 | 0 | 81.00 | 0.33 | 0.00 | 16.7 | 50.0 | 15.00 | 1.000 | 54.00 | 54.00 | ||||
| 25 | | F. Cruz | 24.00 | 2023 | CIN | 2 | 0 | 1 | .000 | 2 | 3.00 | 8 | 0 | 0 | 0 | 3.0 | 1 | 1 | 2 | 0 | 1 | 0 | 0 | 0 | 11 | 0 | 3.00 | 8.00 | 0.00 | 72.7 | 9.1 | 0.67 | .500 | 6.00 | 3.00 |
StatMuse has game-level data for K/9 going back to the 1901 season.
Some of the information used here was obtained free of charge from Retrosheet.
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