Aroldis Chapman has the best K/9 by a relief pitcher when pitching in 500+ games, with 14.58 per nine innings.
Interpreted as:
highest k/9 relief pitcher 500 or more games| NAME | K/9 | 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 |  | A. Chapman | 14.58 | 863 | 60 | 47 | .561 | 0 | 2.52 | 1,331 | 0 | 0 | 367 | 821.1 | 475 | 230 | 255 | 54 | 408 | 33 | 563 | 7 | 3,341 | 87 | 4.47 | 3.26 | 0.59 | 39.8 | 12.2 | 1.08 | .278 | 2.79 | 5.20 |
| 2 |  | E. DÃaz | 14.54 | 520 | 28 | 36 | .438 | 0 | 2.82 | 839 | 0 | 0 | 253 | 519.1 | 356 | 163 | 176 | 54 | 182 | 40 | 395 | 9 | 2,105 | 33 | 3.15 | 4.61 | 0.94 | 39.9 | 8.6 | 1.04 | .305 | 3.05 | 6.17 |
| 3 |  | C. Kimbrel | 14.04 | 851 | 56 | 48 | .538 | 0 | 2.58 | 1,282 | 0 | 0 | 440 | 821.2 | 492 | 236 | 263 | 75 | 346 | 40 | 656 | 11 | 3,306 | 70 | 3.79 | 3.71 | 0.82 | 38.8 | 10.5 | 1.02 | .267 | 2.88 | 5.39 |
| 4 |  | A. Miller | 12.93 | 546 | 35 | 28 | .556 | 0 | 2.95 | 724 | 0 | 0 | 63 | 504.0 | 351 | 165 | 183 | 47 | 201 | 46 | 147 | 9 | 2,091 | 25 | 3.59 | 3.60 | 0.84 | 34.6 | 9.6 | 1.10 | .283 | 3.27 | 6.27 |
| 5 |  | K. Jansen | 12.40 | 934 | 54 | 40 | .574 | 0 | 2.57 | 1,278 | 0 | 0 | 475 | 927.1 | 610 | 265 | 284 | 88 | 282 | 32 | 700 | 20 | 3,680 | 21 | 2.74 | 4.53 | 0.85 | 34.7 | 7.7 | 0.96 | .261 | 2.76 | 5.92 |
| 6 | | C. Marmol | 12.33 | 506 | 18 | 29 | .383 | 0 | 3.25 | 698 | 0 | 0 | 117 | 509.1 | 324 | 184 | 195 | 37 | 340 | 47 | 259 | 20 | 2,207 | 32 | 6.01 | 2.05 | 0.65 | 31.6 | 15.4 | 1.30 | .265 | 3.45 | 5.73 |
| 7 | | B. Wagner | 11.92 | 853 | 47 | 40 | .540 | 0 | 2.31 | 1,196 | 0 | 0 | 422 | 903.0 | 601 | 232 | 262 | 82 | 300 | 33 | 703 | 26 | 3,600 | 43 | 2.99 | 3.99 | 0.82 | 33.2 | 8.3 | 1.00 | .261 | 2.61 | 5.99 |
| 8 | | B. Lidge | 11.92 | 602 | 26 | 32 | .448 | 0 | 3.55 | 795 | 0 | 0 | 225 | 600.1 | 490 | 237 | 257 | 57 | 285 | 33 | 368 | 41 | 2,576 | 46 | 4.27 | 2.79 | 0.85 | 30.9 | 11.1 | 1.29 | .308 | 3.85 | 7.35 |
| 9 | | D. Robertson | 11.84 | 880 | 68 | 46 | .596 | 0 | 2.93 | 1,175 | 0 | 0 | 179 | 893.1 | 674 | 291 | 315 | 81 | 364 | 25 | 358 | 38 | 3,687 | 57 | 3.67 | 3.23 | 0.82 | 31.9 | 9.9 | 1.16 | .290 | 3.17 | 6.79 |
| 10 | | J. Diekman | 11.42 | 705 | 27 | 34 | .443 | 0 | 3.91 | 764 | 0 | 0 | 19 | 602.1 | 483 | 262 | 312 | 53 | 358 | 47 | 141 | 21 | 2,662 | 44 | 5.35 | 2.13 | 0.79 | 28.7 | 13.4 | 1.40 | .299 | 4.66 | 7.22 |
| 11 | | O. Dotel | 11.31 | 724 | 50 | 41 | .549 | 0 | 3.32 | 955 | 0 | 0 | 109 | 760.0 | 576 | 280 | 306 | 84 | 313 | 31 | 305 | 36 | 3,172 | 40 | 3.71 | 3.05 | 0.99 | 30.1 | 9.9 | 1.17 | .275 | 3.62 | 6.82 |
| 12 | | G. Holland | 11.13 | 556 | 30 | 28 | .517 | 0 | 3.14 | 677 | 0 | 0 | 220 | 547.2 | 417 | 191 | 211 | 43 | 241 | 7 | 355 | 20 | 2,271 | 50 | 3.96 | 2.81 | 0.71 | 29.8 | 10.6 | 1.20 | .287 | 3.47 | 6.85 |
| 13 | | H. Neris | 11.12 | 643 | 46 | 43 | .517 | 0 | 3.47 | 775 | 0 | 0 | 107 | 627.1 | 509 | 242 | 272 | 83 | 243 | 36 | 274 | 16 | 2,632 | 38 | 3.49 | 3.19 | 1.19 | 29.4 | 9.2 | 1.20 | .285 | 3.90 | 7.30 |
| 14 | | U. Urbina | 11.03 | 562 | 36 | 42 | .462 | 0 | 3.24 | 718 | 0 | 0 | 237 | 585.2 | 427 | 211 | 225 | 65 | 255 | 5 | 408 | 26 | 2,425 | 25 | 3.92 | 2.82 | 1.00 | 29.6 | 10.5 | 1.16 | .262 | 3.46 | 6.56 |
| 15 | | W. Smith | 11.02 | 601 | 27 | 35 | .435 | 0 | 3.58 | 684 | 0 | 0 | 113 | 558.2 | 452 | 222 | 253 | 71 | 204 | 16 | 237 | 25 | 2,312 | 26 | 3.29 | 3.35 | 1.14 | 29.6 | 8.8 | 1.17 | .285 | 4.08 | 7.28 |
| 16 | | B. Boxberger | 10.95 | 506 | 31 | 38 | .449 | 0 | 3.50 | 581 | 0 | 0 | 84 | 477.2 | 372 | 186 | 204 | 63 | 233 | 23 | 167 | 17 | 2,021 | 16 | 4.39 | 2.49 | 1.19 | 28.7 | 11.5 | 1.27 | .276 | 3.84 | 7.01 |
| 17 | | A. Benitez | 10.93 | 762 | 40 | 47 | .460 | 0 | 3.13 | 946 | 0 | 0 | 289 | 779.0 | 545 | 271 | 296 | 95 | 403 | 16 | 527 | 32 | 3,253 | 18 | 4.66 | 2.35 | 1.10 | 29.1 | 12.4 | 1.22 | .251 | 3.42 | 6.30 |
| 18 | | R. Iglesias | 10.79 | 579 | 38 | 47 | .447 | 0 | 2.74 | 738 | 0 | 0 | 253 | 615.1 | 462 | 187 | 212 | 68 | 168 | 20 | 459 | 17 | 2,461 | 16 | 2.46 | 4.39 | 0.99 | 30.0 | 6.8 | 1.02 | .269 | 3.10 | 6.76 |
| 19 | | O. Perez | 10.59 | 508 | 16 | 27 | .372 | 0 | 3.74 | 433 | 0 | 0 | 5 | 368.0 | 336 | 153 | 172 | 35 | 148 | 35 | 84 | 25 | 1,598 | 18 | 3.62 | 2.93 | 0.86 | 27.1 | 9.3 | 1.32 | .318 | 4.21 | 8.22 |
| 20 |  | B. Hand | 10.59 | 536 | 32 | 31 | .508 | 0 | 3.31 | 647 | 0 | 0 | 132 | 550.0 | 439 | 202 | 230 | 51 | 206 | 41 | 254 | 23 | 2,293 | 25 | 3.37 | 3.14 | 0.83 | 28.2 | 9.0 | 1.17 | .288 | 3.76 | 7.18 |
| 21 | | F. Rodriguez | 10.53 | 948 | 52 | 53 | .495 | 0 | 2.86 | 1,142 | 0 | 0 | 437 | 976.0 | 738 | 310 | 336 | 98 | 389 | 17 | 677 | 42 | 4,011 | 68 | 3.59 | 2.94 | 0.90 | 28.5 | 9.7 | 1.15 | .271 | 3.10 | 6.81 |
| 22 | | A. Ottavino | 10.51 | 724 | 41 | 41 | .500 | 0 | 3.40 | 853 | 0 | 0 | 46 | 730.1 | 609 | 276 | 296 | 68 | 322 | 50 | 168 | 31 | 3,098 | 65 | 3.97 | 2.65 | 0.84 | 27.5 | 10.4 | 1.27 | .300 | 3.65 | 7.50 |
| 23 | | B.J. Ryan | 10.48 | 560 | 21 | 28 | .429 | 0 | 3.37 | 625 | 0 | 0 | 117 | 536.2 | 424 | 201 | 216 | 42 | 264 | 17 | 249 | 27 | 2,273 | 21 | 4.43 | 2.37 | 0.70 | 27.5 | 11.6 | 1.28 | .288 | 3.62 | 7.11 |
| 24 | | J. Nathan | 10.42 | 758 | 52 | 29 | .642 | 0 | 2.50 | 881 | 0 | 0 | 377 | 761.0 | 540 | 211 | 222 | 60 | 248 | 18 | 587 | 27 | 3,048 | 41 | 2.93 | 3.55 | 0.71 | 28.9 | 8.1 | 1.04 | .261 | 2.63 | 6.39 |
| 25 | | T. Rogers | 10.41 | 566 | 31 | 36 | .463 | 0 | 3.34 | 626 | 0 | 0 | 83 | 541.1 | 482 | 201 | 233 | 57 | 165 | 36 | 164 | 22 | 2,256 | 12 | 2.74 | 3.79 | 0.95 | 27.7 | 7.3 | 1.20 | .310 | 3.87 | 8.01 |
StatMuse has game-level data for games pitched going back to the 1908 season.
Some of the information used here was obtained free of charge from Retrosheet.
More Reds Stats
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HR
22
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RBI
86
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AVG
.269
Lux
Team Pitching Leaders 
W
14
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K
163
Singer
ERA
2.76
Greene
Team Rankings
HR
167
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R
716
14th
SO
1,380
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MLB 2025 Batting Leaders
MLB 2025 Pitching Leaders
MLB Fantasy 2025
MLB 2025 Betting
MLB 2025 Standings
| NL East | W | L | PCT | GB |
|---|---|---|---|---|
 Phillies - y | 96 | 66 | .593 | |
83 | 79 | .512 | 13.0 | |
79 | 83 | .488 | 17.0 | |
76 | 86 | .469 | 20.0 | |
66 | 96 | .407 | 30.0 | |
| NL Central | W | L | PCT | GB |
 Brewers - y | 97 | 65 | .599 | |
 Cubs - w | 92 | 70 | .568 | 5.0 |
 Reds - w | 83 | 79 | .512 | 14.0 |
78 | 84 | .481 | 19.0 | |
71 | 91 | .438 | 26.0 | |
| NL West | W | L | PCT | GB |
 Dodgers - y | 93 | 69 | .574 | |
 Padres - w | 90 | 72 | .556 | 3.0 |
81 | 81 | .500 | 12.0 | |
80 | 82 | .494 | 13.0 | |
43 | 119 | .265 | 50.0 |
Mets
Marlins
Braves
Nationals
Giants
Diamondbacks
Rockies| AL East | W | L | PCT | GB |
|---|---|---|---|---|
 Blue Jays - y | 94 | 68 | .580 | |
 Yankees - w | 94 | 68 | .580 | |
 Red Sox - w | 89 | 73 | .549 | 5.0 |
77 | 85 | .475 | 17.0 | |
75 | 87 | .463 | 19.0 | |
| AL Central | W | L | PCT | GB |
 Guardians - y | 88 | 74 | .543 | |
 Tigers - w | 87 | 75 | .537 | 1.0 |
82 | 80 | .506 | 6.0 | |
70 | 92 | .432 | 18.0 | |
60 | 102 | .370 | 28.0 | |
| AL West | W | L | PCT | GB |
 Mariners - y | 90 | 72 | .556 | |
87 | 75 | .537 | 3.0 | |
81 | 81 | .500 | 9.0 | |
76 | 86 | .469 | 14.0 | |
72 | 90 | .444 | 18.0 |
Rays
Orioles
Royals
Twins
White Sox
Astros
Rangers
Athletics
Angels
