| 2012 NL Leaders | |||||||||||||
| Name | Age | Team | G | IP | TBF | BB% | K% | BABIP | LOB% | GB% | HR/Air | ERA | FIP |
| Daniel Runzler | San Francisco | 6 | 3.67 | 15 | 20.0% | 33.3% | .250 | 100% | 33% | 0% | 0.00 | 3.67 | |
| Zach Putnam | 25 | Colorado | 2 | 2.00 | 9 | 11.1% | 0.0% | .429 | 100% | 38% | 0% | 0.00 | 4.63 |
| Joshua Stinson | 24 | Milwaukee | 6 | 9.33 | 38 | 13.2% | 7.9% | .207 | 104% | 48% | 6% | 0.96 | 5.49 |
| 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 |
| Rob Scahill | Colorado | 6 | 8.67 | 33 | 9.1% | 12.1% | .269 | 90% | 52% | 0% | 1.04 | 3.24 | |
| Shelby Miller | St. Louis | 6 | 13.67 | 54 | 7.4% | 29.6% | .273 | 86% | 44% | 0% | 1.32 | 1.88 | |
| Zach Duke | 29 | Washington | 8 | 13.67 | 56 | 7.1% | 17.9% | .262 | 87% | 40% | 0% | 1.32 | 2.54 |
| Steven Rodriguez | LA Dodgers | 11 | 6.67 | 26 | 15.4% | 23.1% | .200 | 86% | 47% | 0% | 1.35 | 3.13 | |
| 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 |
| Peter Moylan | 34 | Atlanta | 8 | 5.00 | 21 | 9.5% | 9.5% | .133 | 56% | 50% | 12% | 1.80 | 6.13 |
| Cory Gearrin | Atlanta | 22 | 20.00 | 80 | 6.3% | 25.0% | .308 | 88% | 58% | 4% | 1.80 | 2.83 | |
| Bryan Morris | 25 | Pittsburgh | 5 | 5.00 | 20 | 10.0% | 30.0% | .200 | 60% | 73% | 0% | 1.80 | 2.53 |
| Tony Cingrani | Cincinnati | 3 | 5.00 | 22 | 9.1% | 40.9% | .300 | 109% | 60% | 23% | 1.80 | 3.33 | |
| Justin Hampson | 32 | NY Mets | 13 | 10.00 | 37 | 13.5% | 10.8% | .222 | 64% | 63% | 0% | 1.80 | 3.83 |
| Huston Street | 29 | San Diego | 40 | 39.00 | 144 | 7.6% | 32.6% | .185 | 79% | 44% | 4% | 1.85 | 2.23 |
| Justin Wilson | 25 | Pittsburgh | 8 | 4.67 | 26 | 11.5% | 26.9% | .667 | 92% | 19% | 0% | 1.93 | 2.06 |
| 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 | |
| Christian Garcia | 27 | Washington | 13 | 12.67 | 48 | 4.2% | 31.3% | .231 | 98% | 28% | 10% | 2.13 | 3.76 |
| 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 |
