| 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 | |
| Aroldis Chapman | Cincinnati | 68 | 71.67 | 276 | 8.3% | 44.2% | .254 | 87% | 38% | 5% | 1.51 | 1.58 | |
| Tony Cingrani | Cincinnati | 3 | 5.00 | 22 | 9.1% | 40.9% | .300 | 109% | 60% | 23% | 1.80 | 3.33 | |
| Kenley Jansen | 25 | LA Dodgers | 65 | 65.00 | 252 | 8.7% | 39.3% | .225 | 81% | 34% | 7% | 2.35 | 2.44 |
| Jason Grilli | 36 | Pittsburgh | 64 | 58.67 | 244 | 9.0% | 36.9% | .328 | 83% | 30% | 8% | 2.91 | 2.84 |
| Thomas Layne | 28 | San Diego | 26 | 16.67 | 68 | 4.4% | 36.8% | .250 | 60% | 48% | 0% | 3.24 | 1.21 |
| Maikel Cleto | 23 | St. Louis | 9 | 9.00 | 41 | 4.9% | 36.6% | .474 | 87% | 32% | 26% | 7.00 | 6.57 |
| Antonio Bastardo | 27 | Philadelphia | 65 | 52.00 | 224 | 11.6% | 36.2% | .324 | 72% | 28% | 9% | 4.33 | 3.38 |
| Ernesto Frieri | 27 | San Diego | 11 | 11.67 | 50 | 8.0% | 36.0% | .292 | 82% | 30% | 11% | 2.31 | 3.81 |
| David Hernandez | 27 | Arizona | 72 | 68.33 | 278 | 7.9% | 35.3% | .295 | 77% | 31% | 4% | 2.37 | 2.12 |
| Jim Henderson | 30 | Milwaukee | 36 | 30.67 | 131 | 9.9% | 34.4% | .358 | 72% | 43% | 2% | 3.23 | 1.99 |
| Daniel Runzler | San Francisco | 6 | 3.67 | 15 | 20.0% | 33.3% | .250 | 100% | 33% | 0% | 0.00 | 3.67 | |
| Huston Street | 29 | San Diego | 40 | 39.00 | 144 | 7.6% | 32.6% | .185 | 79% | 44% | 4% | 1.85 | 2.23 |
| Jonathan Papelbon | 32 | Philadelphia | 70 | 70.00 | 284 | 6.3% | 32.4% | .310 | 84% | 44% | 8% | 2.83 | 2.93 |
| Jeremy Horst | Philadelphia | 32 | 31.33 | 125 | 11.2% | 32.0% | .299 | 81% | 45% | 3% | 1.72 | 2.43 | |
| Christian Garcia | 27 | Washington | 13 | 12.67 | 48 | 4.2% | 31.3% | .231 | 98% | 28% | 10% | 2.13 | 3.76 |
| Raul Valdes | Philadelphia | 27 | 31.00 | 113 | 4.4% | 31.0% | .221 | 69% | 25% | 6% | 2.90 | 2.61 | |
| Jason Motte | 30 | St. Louis | 67 | 72.00 | 279 | 6.1% | 30.8% | .248 | 81% | 41% | 9% | 2.75 | 3.16 |
| Stephen Strasburg | Washington | 28 | 159.33 | 653 | 7.4% | 30.2% | .320 | 75% | 43% | 7% | 3.16 | 2.86 | |
| John Axford | Milwaukee | 75 | 69.33 | 310 | 12.6% | 30.0% | .317 | 68% | 47% | 11% | 4.80 | 4.09 | |
| Bryan Morris | 25 | Pittsburgh | 5 | 5.00 | 20 | 10.0% | 30.0% | .200 | 60% | 73% | 0% | 1.80 | 2.53 |
| J.J. Putz | 35 | Arizona | 57 | 54.33 | 218 | 5.0% | 29.8% | .311 | 76% | 46% | 5% | 2.82 | 2.41 |
| Shelby Miller | St. Louis | 6 | 13.67 | 54 | 7.4% | 29.6% | .273 | 86% | 44% | 0% | 1.32 | 1.88 | |
| Sergio Romo | 29 | San Francisco | 69 | 55.33 | 215 | 4.7% | 29.3% | .242 | 91% | 48% | 7% | 1.79 | 2.73 |
| Carlos Marmol | 30 | Chi Cubs | 61 | 55.33 | 247 | 18.2% | 29.1% | .290 | 77% | 41% | 5% | 3.42 | 4.01 |
| Sean Marshall | 30 | Cincinnati | 73 | 61.00 | 256 | 6.3% | 28.9% | .329 | 80% | 58% | 4% | 2.51 | 2.28 |
| Juan Perez | 34 | Milwaukee | 10 | 7.00 | 35 | 22.9% | 28.6% | .308 | 90% | 47% | 25% | 5.14 | 7.84 |
| Matthew Harvey | NY Mets | 10 | 59.33 | 245 | 10.6% | 28.6% | .274 | 81% | 40% | 6% | 2.73 | 3.33 | |
| Hisanori Takahashi | Pittsburgh | 9 | 8.33 | 39 | 10.3% | 28.2% | .381 | 54% | 46% | 15% | 8.64 | 5.05 | |
| Rex Brothers | Colorado | 75 | 67.67 | 295 | 12.5% | 28.1% | .372 | 72% | 48% | 6% | 3.86 | 3.32 | |
