| 2012 NL Leaders | |||||||||||||
| Name | Age | Team | G | IP | TBF | BB% | K% | BABIP | LOB% | GB% | HR/Air | ERA | FIP |
| Craig Kimbrel | Atlanta | 63 | 62.67 | 231 | 6.1% | 50.2% | .250 | 93% | 50% | 6% | 1.01 | 0.81 | |
| Edward Mujica | 28 | St. Louis | 29 | 26.33 | 97 | 3.1% | 21.6% | .271 | 93% | 51% | 3% | 1.03 | 2.37 |
| Aroldis Chapman | Cincinnati | 68 | 71.67 | 276 | 8.3% | 44.2% | .254 | 87% | 38% | 5% | 1.51 | 1.58 | |
| Kristopher Medlen | 27 | Atlanta | 50 | 138.00 | 520 | 4.4% | 23.1% | .262 | 85% | 55% | 4% | 1.57 | 2.45 |
| Nick Vincent | San Diego | 27 | 26.33 | 105 | 6.7% | 26.7% | .258 | 91% | 40% | 5% | 1.71 | 2.90 | |
| Jeremy Horst | Philadelphia | 32 | 31.33 | 125 | 11.2% | 32.0% | .299 | 81% | 45% | 3% | 1.72 | 2.43 | |
| Eric O'Flaherty | 27 | Atlanta | 64 | 57.33 | 230 | 8.3% | 20.0% | .286 | 85% | 63% | 5% | 1.73 | 3.30 |
| Sergio Romo | 29 | San Francisco | 69 | 55.33 | 215 | 4.7% | 29.3% | .242 | 91% | 48% | 7% | 1.79 | 2.73 |
| Huston Street | 29 | San Diego | 40 | 39.00 | 144 | 7.6% | 32.6% | .185 | 79% | 44% | 4% | 1.85 | 2.23 |
| Brandon Beachey | Atlanta | 13 | 81.00 | 319 | 9.1% | 21.3% | .204 | 78% | 43% | 5% | 2.00 | 3.52 | |
| Luis Avilan | 23 | Atlanta | 31 | 36.00 | 142 | 7.0% | 23.2% | .280 | 79% | 45% | 2% | 2.00 | 2.57 |
| J.J. Hoover | Cincinnati | 28 | 30.67 | 123 | 10.6% | 25.2% | .203 | 85% | 22% | 3% | 2.05 | 3.23 | |
| Wilton Lopez | Houston | 64 | 66.33 | 260 | 3.1% | 20.8% | .310 | 81% | 55% | 5% | 2.17 | 2.74 | |
| Scott Elbert | 27 | LA Dodgers | 43 | 32.67 | 133 | 9.8% | 21.8% | .286 | 90% | 38% | 5% | 2.20 | 3.83 |
| Mitchell Boggs | 28 | St. Louis | 78 | 73.33 | 296 | 7.1% | 19.6% | .252 | 82% | 54% | 5% | 2.21 | 3.45 |
| Ryan Dempster | 35 | Chi Cubs | 16 | 104.00 | 417 | 6.5% | 19.9% | .241 | 84% | 43% | 5% | 2.25 | 3.46 |
| Brandon League | 29 | LA Dodgers | 28 | 27.33 | 108 | 13.0% | 25.0% | .274 | 78% | 59% | 0% | 2.31 | 2.80 |
| Craig Stammen | 28 | Washington | 59 | 88.33 | 370 | 9.7% | 23.5% | .276 | 82% | 45% | 5% | 2.34 | 3.48 |
| Kenley Jansen | 25 | LA Dodgers | 65 | 65.00 | 252 | 8.7% | 39.3% | .225 | 81% | 34% | 7% | 2.35 | 2.44 |
| Drew Storen | Washington | 37 | 30.33 | 116 | 6.9% | 20.7% | .272 | 74% | 53% | 0% | 2.37 | 2.44 | |
| David Hernandez | 27 | Arizona | 72 | 68.33 | 278 | 7.9% | 35.3% | .295 | 77% | 31% | 4% | 2.37 | 2.12 |
| Sean Burnett | 30 | Washington | 70 | 56.67 | 239 | 5.0% | 23.8% | .344 | 85% | 60% | 6% | 2.38 | 2.83 |
| Luke Gregerson | 28 | San Diego | 77 | 71.67 | 294 | 7.1% | 24.5% | .272 | 87% | 51% | 7% | 2.39 | 3.39 |
| George Kontos | 27 | San Francisco | 44 | 43.67 | 177 | 6.8% | 24.9% | .267 | 74% | 50% | 5% | 2.47 | 2.83 |
| Wily Peralta | 23 | Milwaukee | 6 | 29.00 | 113 | 9.7% | 20.4% | .316 | 77% | 53% | 0% | 2.48 | 2.68 |
| Bobby Parnell | 28 | NY Mets | 74 | 68.67 | 288 | 6.9% | 21.2% | .309 | 77% | 61% | 5% | 2.49 | 3.03 |
| Brad Ziegler | 33 | Arizona | 77 | 68.67 | 263 | 8.0% | 16.0% | .267 | 75% | 77% | 4% | 2.49 | 3.24 |
| Sean Marshall | 30 | Cincinnati | 73 | 61.00 | 256 | 6.3% | 28.9% | .329 | 80% | 58% | 4% | 2.51 | 2.28 |
| Clayton Kershaw | 24 | LA Dodgers | 33 | 227.67 | 901 | 7.0% | 25.4% | .275 | 78% | 47% | 5% | 2.53 | 2.93 |
| Ronald Belizario | LA Dodgers | 68 | 71.00 | 286 | 10.1% | 24.1% | .250 | 77% | 65% | 5% | 2.54 | 3.13 | |
