| 2012 NL Leaders | |||||||||||||||||
| Name | Age | Team | G | W | L | IP | TBF | H | 2B | 3B | HR | R | ER | BB | SO | ERA | RA9 |
| Shawn Camp | 37 | Chi Cubs | 80 | 3 | 6 | 77.2 | 327 | 79 | 13 | 6 | 7 | 32 | 30 | 21 | 54 | 3.48 | 3.71 |
| Matt Belisle | 32 | Colorado | 80 | 3 | 8 | 80.0 | 348 | 91 | 18 | 2 | 5 | 36 | 33 | 18 | 69 | 3.71 | 4.05 |
| Mitchell Boggs | 28 | St. Louis | 78 | 4 | 1 | 73.1 | 296 | 56 | 6 | 0 | 5 | 20 | 18 | 21 | 58 | 2.21 | 2.45 |
| Francisco Rodriguez | 29 | Milwaukee | 78 | 2 | 7 | 72.0 | 305 | 65 | 13 | 2 | 8 | 37 | 35 | 31 | 72 | 4.38 | 4.62 |
| Brad Ziegler | 33 | Arizona | 77 | 6 | 1 | 68.2 | 263 | 53 | 6 | 1 | 2 | 21 | 19 | 21 | 42 | 2.49 | 2.75 |
| Wesley Wright | 28 | Houston | 77 | 2 | 2 | 52.1 | 223 | 45 | 3 | 3 | 4 | 20 | 19 | 17 | 54 | 3.27 | 3.44 |
| Luke Gregerson | 28 | San Diego | 77 | 2 | 0 | 71.2 | 294 | 57 | 10 | 0 | 7 | 19 | 19 | 21 | 72 | 2.39 | 2.39 |
| James Russell | 26 | Chi Cubs | 77 | 7 | 1 | 69.1 | 292 | 65 | 22 | 3 | 5 | 28 | 23 | 23 | 55 | 2.99 | 3.63 |
| Chad Durbin | 35 | Atlanta | 76 | 4 | 1 | 61.0 | 257 | 52 | 8 | 1 | 9 | 25 | 21 | 28 | 49 | 3.10 | 3.69 |
| Rex Brothers | Colorado | 75 | 8 | 2 | 67.2 | 295 | 63 | 13 | 3 | 5 | 33 | 29 | 37 | 83 | 3.86 | 4.39 | |
| John Axford | Milwaukee | 75 | 5 | 8 | 69.1 | 310 | 61 | 6 | 3 | 10 | 42 | 37 | 39 | 93 | 4.80 | 5.45 | |
| Bobby Parnell | 28 | NY Mets | 74 | 5 | 4 | 68.2 | 288 | 64 | 11 | 1 | 4 | 24 | 19 | 20 | 61 | 2.49 | 3.15 |
| Tyler Clippard | 27 | Washington | 74 | 2 | 6 | 72.2 | 307 | 55 | 11 | 2 | 7 | 32 | 30 | 29 | 84 | 3.72 | 3.96 |
| Jon Rauch | 34 | NY Mets | 73 | 3 | 7 | 57.2 | 233 | 45 | 11 | 1 | 7 | 28 | 23 | 12 | 42 | 3.59 | 4.37 |
| Santiago Casilla | 32 | San Francisco | 73 | 7 | 6 | 63.1 | 272 | 55 | 10 | 0 | 8 | 24 | 20 | 22 | 55 | 2.84 | 3.41 |
| Sean Marshall | 30 | Cincinnati | 73 | 5 | 5 | 61.0 | 256 | 55 | 7 | 1 | 3 | 18 | 17 | 16 | 74 | 2.51 | 2.66 |
| Jose Veras | 32 | Milwaukee | 72 | 5 | 4 | 67.0 | 300 | 61 | 9 | 2 | 5 | 29 | 27 | 40 | 79 | 3.63 | 3.90 |
| David Hernandez | 27 | Arizona | 72 | 2 | 3 | 68.1 | 278 | 48 | 9 | 1 | 4 | 21 | 18 | 22 | 98 | 2.37 | 2.77 |
| Matthew Reynolds | Colorado | 71 | 3 | 1 | 57.1 | 249 | 65 | 15 | 1 | 11 | 31 | 28 | 17 | 51 | 4.40 | 4.87 | |
| Fernando Rodriguez | 28 | Houston | 71 | 2 | 10 | 70.1 | 309 | 68 | 11 | 3 | 10 | 45 | 42 | 34 | 78 | 5.37 | 5.76 |
| Jonathan Papelbon | 32 | Philadelphia | 70 | 5 | 6 | 70.0 | 284 | 57 | 8 | 1 | 8 | 22 | 22 | 18 | 92 | 2.83 | 2.83 |
| Javier Lopez | 35 | San Francisco | 70 | 3 | 0 | 36.0 | 153 | 37 | 8 | 1 | 1 | 13 | 11 | 14 | 28 | 2.75 | 3.25 |
| Kameron Loe | 31 | Milwaukee | 70 | 6 | 5 | 68.1 | 303 | 78 | 18 | 0 | 9 | 41 | 35 | 20 | 55 | 4.61 | 5.40 |
| Sean Burnett | 30 | Washington | 70 | 1 | 2 | 56.2 | 239 | 58 | 11 | 0 | 4 | 16 | 15 | 12 | 57 | 2.38 | 2.54 |
| Marc Rzepczynski | St. Louis | 70 | 1 | 3 | 46.2 | 196 | 46 | 6 | 0 | 7 | 22 | 22 | 17 | 33 | 4.24 | 4.24 | |
| Sergio Romo | 29 | San Francisco | 69 | 4 | 2 | 55.1 | 215 | 37 | 6 | 0 | 5 | 11 | 11 | 10 | 63 | 1.79 | 1.79 |
| Anthony Watson | 27 | Pittsburgh | 68 | 5 | 2 | 53.1 | 215 | 37 | 9 | 1 | 5 | 21 | 20 | 23 | 53 | 3.38 | 3.54 |
| Aroldis Chapman | Cincinnati | 68 | 5 | 5 | 71.2 | 276 | 35 | 7 | 1 | 4 | 13 | 12 | 23 | 122 | 1.51 | 1.63 | |
| Ronald Belizario | LA Dodgers | 68 | 8 | 1 | 71.0 | 286 | 47 | 12 | 1 | 3 | 22 | 20 | 29 | 69 | 2.54 | 2.79 | |
| Jeremy Affeldt | 33 | San Francisco | 67 | 1 | 2 | 63.1 | 267 | 57 | 13 | 2 | 1 | 23 | 19 | 23 | 57 | 2.70 | 3.27 |
