| 2012 NL Leaders | |||||||||||||
| Name | Age | Team | G | IP | TBF | BB% | K% | BABIP | LOB% | GB% | HR/Air | ERA | FIP |
| Wilton Lopez | Houston | 64 | 66.33 | 260 | 3.1% | 20.8% | .310 | 81% | 55% | 5% | 2.17 | 2.74 | |
| Edward Mujica | 28 | St. Louis | 29 | 26.33 | 97 | 3.1% | 21.6% | .271 | 93% | 51% | 3% | 1.03 | 2.37 |
| Joe Blanton | 32 | Philadelphia | 21 | 133.33 | 560 | 3.2% | 20.5% | .304 | 67% | 43% | 9% | 4.59 | 4.02 |
| Cliff Lee | 34 | Philadelphia | 30 | 211.00 | 847 | 3.3% | 24.4% | .313 | 79% | 46% | 8% | 3.16 | 3.17 |
| Jonathan Broxton | 28 | Cincinnati | 25 | 22.33 | 87 | 3.4% | 23.0% | .306 | 75% | 49% | 3% | 2.82 | 2.46 |
| Jeff Karstens | 30 | Pittsburgh | 19 | 90.67 | 372 | 4.0% | 17.7% | .295 | 68% | 38% | 4% | 3.97 | 3.35 |
| Bronson Arroyo | 35 | Cincinnati | 32 | 202.00 | 835 | 4.2% | 15.4% | .292 | 77% | 43% | 7% | 3.74 | 4.12 |
| Jeff Francis | 32 | Colorado | 24 | 113.00 | 502 | 4.4% | 15.1% | .358 | 68% | 51% | 8% | 5.58 | 4.30 |
| Kyle Lohse | 34 | St. Louis | 33 | 211.00 | 864 | 4.4% | 16.6% | .270 | 77% | 41% | 5% | 2.86 | 3.54 |
| Jeremy Hefner | NY Mets | 26 | 93.67 | 408 | 4.4% | 15.2% | .325 | 64% | 45% | 5% | 5.09 | 3.69 | |
| Raul Valdes | Philadelphia | 27 | 31.00 | 113 | 4.4% | 31.0% | .221 | 69% | 25% | 6% | 2.90 | 2.61 | |
| Kristopher Medlen | 27 | Atlanta | 50 | 138.00 | 520 | 4.4% | 23.1% | .262 | 85% | 55% | 4% | 1.57 | 2.45 |
| Brett Myers | 32 | Houston | 35 | 30.67 | 134 | 4.5% | 14.9% | .316 | 70% | 55% | 8% | 3.52 | 4.30 |
| Wade Miley | Arizona | 32 | 194.67 | 807 | 4.6% | 17.8% | .298 | 72% | 44% | 4% | 3.33 | 3.18 | |
| Clayton Richard | 29 | San Diego | 33 | 218.67 | 910 | 4.6% | 11.8% | .276 | 71% | 54% | 9% | 3.99 | 4.65 |
| Sergio Romo | 29 | San Francisco | 69 | 55.33 | 215 | 4.7% | 29.3% | .242 | 91% | 48% | 7% | 1.79 | 2.73 |
| Charlie Morton | 29 | Pittsburgh | 9 | 50.33 | 223 | 4.9% | 11.2% | .331 | 66% | 56% | 6% | 4.65 | 4.20 |
| Sean Burnett | 30 | Washington | 70 | 56.67 | 239 | 5.0% | 23.8% | .344 | 85% | 60% | 6% | 2.38 | 2.83 |
| J.J. Putz | 35 | Arizona | 57 | 54.33 | 218 | 5.0% | 29.8% | .311 | 76% | 46% | 5% | 2.82 | 2.41 |
| Tyler Cloyd | 25 | Philadelphia | 6 | 33.00 | 138 | 5.1% | 21.7% | .281 | 78% | 35% | 12% | 4.91 | 5.28 |
| Rafael Betancourt | 37 | Colorado | 60 | 57.67 | 236 | 5.1% | 24.2% | .307 | 81% | 37% | 6% | 2.81 | 3.13 |
| Dale Thayer | 32 | San Diego | 64 | 57.67 | 235 | 5.1% | 20.0% | .308 | 70% | 42% | 4% | 3.43 | 3.08 |
| Livan Hernandez | 37 | Milwaukee | 26 | 36.33 | 156 | 5.1% | 18.6% | .324 | 56% | 44% | 15% | 7.68 | 5.85 |
| Jon Rauch | 34 | NY Mets | 73 | 57.67 | 233 | 5.2% | 18.0% | .232 | 62% | 38% | 6% | 3.59 | 3.93 |
| Marco Estrada | 29 | Milwaukee | 29 | 138.33 | 562 | 5.2% | 25.4% | .307 | 72% | 35% | 7% | 3.64 | 3.38 |
| Matt Belisle | 32 | Colorado | 80 | 80.00 | 348 | 5.2% | 19.8% | .352 | 72% | 50% | 4% | 3.71 | 3.00 |
| Jordan Zimmermann | Washington | 32 | 195.67 | 805 | 5.3% | 19.0% | .295 | 79% | 44% | 5% | 2.94 | 3.54 | |
| Mike Leake | Cincinnati | 30 | 179.00 | 757 | 5.4% | 15.3% | .314 | 71% | 49% | 9% | 4.58 | 4.46 | |
| Patrick Corbin | Arizona | 22 | 107.00 | 454 | 5.5% | 18.9% | .326 | 71% | 47% | 8% | 4.54 | 4.03 | |
| Johnny Cueto | 26 | Cincinnati | 33 | 217.00 | 888 | 5.5% | 19.1% | .304 | 79% | 49% | 5% | 2.78 | 3.30 |
