Between 2023 and 2025, Mason Miller had the best K/9 by a relief pitcher when pitching at least 127 innings, with 14.53 per nine innings.
| NAME | K/9 | IP | G | W | L | W% | GS | ERA | SO | CG | SHO | SV | H | ER | R | HR | BB | HBP | GF | IBB | TBF | WP | BB/9 | K/BB | HR/9 | K% | BB% | WHIP | BABIP | RA | H/9 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 |  | M. Miller | 14.53 | 135.2 | 119 | 3 | 4 | .429 | 0 | 2.65 | 219 | 0 | 0 | 50 | 71 | 40 | 47 | 12 | 54 | 3 | 81 | 5 | 521 | 6 | 3.58 | 4.06 | 0.80 | 42.0 | 10.4 | 0.92 | .253 | 3.12 | 4.71 |
| 2 |  | A. Chapman | 14.19 | 181.1 | 196 | 16 | 12 | .571 | 0 | 2.68 | 286 | 0 | 0 | 52 | 109 | 54 | 64 | 12 | 90 | 3 | 79 | 2 | 742 | 19 | 4.47 | 3.18 | 0.60 | 38.5 | 12.1 | 1.10 | .276 | 3.18 | 5.41 |
| 3 |  | D. Williams | 13.59 | 142.1 | 150 | 13 | 9 | .591 | 0 | 2.91 | 215 | 0 | 0 | 68 | 81 | 46 | 53 | 10 | 64 | 7 | 97 | 3 | 578 | 6 | 4.05 | 3.36 | 0.63 | 37.2 | 11.1 | 1.02 | .252 | 3.35 | 5.12 |
| 4 | | F. Cruz | 13.47 | 171.2 | 171 | 7 | 13 | .350 | 0 | 4.56 | 257 | 0 | 0 | 2 | 133 | 87 | 91 | 18 | 85 | 6 | 25 | 2 | 731 | 18 | 4.46 | 3.02 | 0.94 | 35.2 | 11.6 | 1.27 | .315 | 4.77 | 6.97 |
| 5 | | J. Estrada | 13.38 | 144.2 | 151 | 10 | 8 | .556 | 0 | 3.48 | 215 | 0 | 0 | 4 | 112 | 56 | 61 | 20 | 62 | 3 | 26 | 4 | 612 | 8 | 3.86 | 3.47 | 1.24 | 35.1 | 10.1 | 1.20 | .295 | 3.79 | 6.97 |
| 6 |  | J. Hader | 13.30 | 180.0 | 180 | 16 | 13 | .552 | 0 | 2.50 | 266 | 0 | 0 | 94 | 104 | 50 | 60 | 23 | 71 | 6 | 155 | 3 | 715 | 9 | 3.55 | 3.75 | 1.15 | 37.2 | 9.9 | 0.97 | .232 | 3.00 | 5.20 |
| 7 | | B. Abreu | 12.52 | 221.1 | 220 | 9 | 9 | .500 | 0 | 2.40 | 308 | 0 | 0 | 13 | 154 | 59 | 62 | 19 | 94 | 13 | 38 | 0 | 908 | 9 | 3.82 | 3.28 | 0.77 | 33.9 | 10.4 | 1.12 | .285 | 2.52 | 6.26 |
| 8 |  | C. Smith | 12.50 | 149.0 | 150 | 14 | 6 | .700 | 0 | 2.42 | 207 | 0 | 0 | 17 | 106 | 40 | 47 | 5 | 36 | 7 | 32 | 3 | 589 | 3 | 2.17 | 5.75 | 0.30 | 35.1 | 6.1 | 0.95 | .302 | 2.84 | 6.40 |
| 9 |  | C. Kimbrel | 12.42 | 133.1 | 142 | 15 | 12 | .556 | 0 | 3.98 | 184 | 0 | 0 | 46 | 94 | 59 | 67 | 19 | 66 | 9 | 89 | 2 | 559 | 7 | 4.46 | 2.79 | 1.28 | 32.9 | 11.8 | 1.20 | .267 | 4.52 | 6.35 |
| 10 |  | A. Muñoz | 11.97 | 170.2 | 176 | 9 | 17 | .346 | 0 | 2.21 | 227 | 0 | 0 | 73 | 107 | 42 | 54 | 10 | 76 | 12 | 109 | 9 | 697 | 14 | 4.01 | 2.99 | 0.53 | 32.6 | 10.9 | 1.07 | .261 | 2.85 | 5.64 |
| 11 | | K. Yates | 11.96 | 163.1 | 172 | 18 | 7 | .720 | 0 | 2.98 | 217 | 0 | 0 | 41 | 96 | 54 | 58 | 21 | 82 | 8 | 81 | 6 | 669 | 7 | 4.52 | 2.65 | 1.16 | 32.4 | 12.3 | 1.09 | .220 | 3.20 | 5.29 |
| 12 | | A. Vesia | 11.80 | 174.2 | 190 | 9 | 11 | .450 | 0 | 2.94 | 229 | 0 | 0 | 11 | 121 | 57 | 67 | 23 | 72 | 8 | 31 | 9 | 713 | 7 | 3.71 | 3.18 | 1.19 | 32.1 | 10.1 | 1.10 | .257 | 3.45 | 6.23 |
| 13 | | G. Jax | 11.68 | 200.1 | 214 | 12 | 22 | .353 | 0 | 3.37 | 260 | 0 | 0 | 14 | 166 | 75 | 82 | 16 | 54 | 7 | 36 | 5 | 824 | 5 | 2.43 | 4.81 | 0.72 | 31.6 | 6.6 | 1.10 | .308 | 3.68 | 7.46 |
| 14 | | J. Hoffman | 11.67 | 186.2 | 193 | 17 | 12 | .586 | 0 | 3.04 | 242 | 0 | 0 | 44 | 131 | 63 | 70 | 24 | 62 | 9 | 93 | 3 | 760 | 11 | 2.99 | 3.90 | 1.16 | 31.8 | 8.2 | 1.03 | .253 | 3.38 | 6.32 |
| 15 | | D. Robertson | 11.55 | 155.0 | 150 | 11 | 10 | .524 | 0 | 3.14 | 199 | 0 | 0 | 22 | 124 | 54 | 62 | 16 | 60 | 8 | 48 | 7 | 643 | 13 | 3.48 | 3.32 | 0.93 | 30.9 | 9.3 | 1.19 | .300 | 3.60 | 7.20 |
| 16 | | G. Speier | 11.48 | 140.1 | 174 | 6 | 7 | .462 | 0 | 3.59 | 179 | 0 | 0 | 1 | 109 | 56 | 58 | 14 | 36 | 10 | 15 | 6 | 563 | 4 | 2.31 | 4.97 | 0.90 | 31.8 | 6.4 | 1.03 | .293 | 3.72 | 6.99 |
| 17 | | M. Leiter Jr. | 11.44 | 170.2 | 188 | 11 | 15 | .423 | 0 | 4.22 | 217 | 0 | 0 | 6 | 160 | 80 | 92 | 20 | 63 | 15 | 30 | 1 | 744 | 15 | 3.32 | 3.44 | 1.05 | 29.2 | 8.5 | 1.31 | .326 | 4.85 | 8.44 |
| 18 | | G. Cleavinger | 11.27 | 133.1 | 150 | 10 | 11 | .476 | 0 | 3.04 | 167 | 0 | 0 | 8 | 98 | 45 | 51 | 17 | 55 | 15 | 27 | 0 | 557 | 4 | 3.71 | 3.04 | 1.15 | 30.0 | 9.9 | 1.15 | .267 | 3.44 | 6.62 |
| 19 | | J. Leclerc | 11.13 | 132.2 | 131 | 6 | 8 | .429 | 0 | 3.73 | 164 | 0 | 0 | 5 | 106 | 55 | 58 | 15 | 65 | 6 | 38 | 3 | 567 | 8 | 4.41 | 2.52 | 1.02 | 28.9 | 11.5 | 1.29 | .287 | 3.93 | 7.19 |
| 20 | | C. Doval | 11.11 | 192.0 | 200 | 15 | 12 | .556 | 0 | 3.75 | 237 | 0 | 0 | 76 | 156 | 80 | 101 | 12 | 100 | 13 | 137 | 9 | 830 | 21 | 4.69 | 2.37 | 0.56 | 28.6 | 12.0 | 1.33 | .308 | 4.73 | 7.31 |
| 21 | | J. Alvarado | 11.09 | 129.0 | 136 | 6 | 9 | .400 | 0 | 3.28 | 159 | 0 | 0 | 30 | 106 | 47 | 57 | 13 | 53 | 2 | 43 | 2 | 544 | 10 | 3.70 | 3.00 | 0.91 | 29.2 | 9.7 | 1.23 | .293 | 3.98 | 7.40 |
| 22 |  | J. Duran | 11.09 | 186.2 | 189 | 16 | 21 | .432 | 0 | 2.65 | 230 | 0 | 0 | 82 | 152 | 55 | 74 | 13 | 59 | 13 | 133 | 11 | 770 | 12 | 2.84 | 3.90 | 0.63 | 29.9 | 7.7 | 1.13 | .305 | 3.57 | 7.33 |
| 23 | | R. Garrett | 11.03 | 131.1 | 121 | 12 | 11 | .522 | 0 | 4.25 | 161 | 0 | 0 | 7 | 119 | 62 | 69 | 14 | 63 | 4 | 24 | 3 | 569 | 6 | 4.32 | 2.56 | 0.96 | 28.3 | 11.1 | 1.39 | .321 | 4.73 | 8.15 |
| 24 | | R. Helsley | 10.98 | 159.0 | 156 | 13 | 12 | .520 | 0 | 3.00 | 194 | 0 | 0 | 84 | 133 | 53 | 62 | 12 | 65 | 2 | 123 | 7 | 664 | 11 | 3.68 | 2.98 | 0.68 | 29.2 | 9.8 | 1.25 | .309 | 3.51 | 7.53 |
| 25 | | P. Johnson | 10.92 | 178.0 | 190 | 11 | 15 | .423 | 0 | 3.59 | 216 | 0 | 0 | 16 | 163 | 71 | 80 | 24 | 74 | 3 | 53 | 4 | 751 | 8 | 3.74 | 2.92 | 1.21 | 28.8 | 9.9 | 1.33 | .320 | 4.04 | 8.24 |
StatMuse has game-level data for K/9 and innings pitched going back to the 1901 season.
Some of the information used here was obtained free of charge from Retrosheet.
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| NL East | W | L | PCT | GB |
|---|---|---|---|---|
 Braves - y | 94 | 68 | .580 | |
 Phillies - w | 88 | 74 | .543 | 6.0 |
80 | 82 | .494 | 14.0 | |
77 | 85 | .475 | 17.0 | |
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| NL Central | W | L | PCT | GB |
 Brewers - y | 103 | 59 | .636 | |
 Cubs - w | 89 | 73 | .549 | 14.0 |
82 | 80 | .506 | 21.0 | |
77 | 85 | .475 | 26.0 | |
75 | 87 | .463 | 28.0 | |
| NL West | W | L | PCT | GB |
 Dodgers - y | 100 | 62 | .617 | |
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86 | 76 | .531 | 14.0 | |
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58 | 104 | .358 | 42.0 |
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|---|---|---|---|---|
 Rays - y | 98 | 64 | .605 | |
 Yankees - w | 93 | 68 | .578 | 4.5 |
 Red Sox - w | 87 | 75 | .537 | 11.0 |
79 | 82 | .491 | 18.5 | |
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| AL Central | W | L | PCT | GB |
 Guardians - y | 85 | 77 | .525 | |
 White Sox - w | 84 | 78 | .519 | 1.0 |
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| AL West | W | L | PCT | GB |
 Astros - y | 81 | 81 | .500 | |
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