| 2012 NL Leaders | |||||||||||||||||
| Name | Age | Team | G | W | L | IP | TBF | H | 2B | 3B | HR | R | ER | BB | SO | ERA | RA9 |
| Craig Kimbrel | Atlanta | 63 | 3 | 1 | 62.2 | 231 | 27 | 1 | 0 | 3 | 7 | 7 | 14 | 116 | 1.01 | 1.01 | |
| Wesley Wright | 28 | Houston | 77 | 2 | 2 | 52.1 | 223 | 45 | 3 | 3 | 4 | 20 | 19 | 17 | 54 | 3.27 | 3.44 |
| Manny Acosta | 31 | NY Mets | 45 | 1 | 3 | 47.1 | 216 | 48 | 4 | 0 | 7 | 38 | 34 | 25 | 46 | 6.47 | 7.23 |
| Ted Lilly | 36 | LA Dodgers | 8 | 5 | 1 | 48.2 | 202 | 36 | 4 | 2 | 3 | 23 | 17 | 19 | 31 | 3.14 | 4.25 |
| Brad Brach | San Diego | 67 | 2 | 4 | 66.2 | 280 | 50 | 6 | 0 | 11 | 28 | 28 | 33 | 75 | 3.78 | 3.78 | |
| Antonio Bastardo | 27 | Philadelphia | 65 | 2 | 5 | 52.0 | 224 | 40 | 6 | 1 | 7 | 26 | 25 | 26 | 81 | 4.33 | 4.50 |
| Javy Guerra | 27 | LA Dodgers | 45 | 2 | 3 | 44.2 | 196 | 44 | 6 | 1 | 1 | 13 | 13 | 23 | 37 | 2.62 | 2.62 |
| Marc Rzepczynski | St. Louis | 70 | 1 | 3 | 46.2 | 196 | 46 | 6 | 0 | 7 | 22 | 22 | 17 | 33 | 4.24 | 4.24 | |
| Dale Thayer | 32 | San Diego | 64 | 2 | 2 | 57.2 | 235 | 53 | 6 | 1 | 4 | 24 | 22 | 12 | 47 | 3.43 | 3.75 |
| John Axford | Milwaukee | 75 | 5 | 8 | 69.1 | 310 | 61 | 6 | 3 | 10 | 42 | 37 | 39 | 93 | 4.80 | 5.45 | |
| Mitchell Boggs | 28 | St. Louis | 78 | 4 | 1 | 73.1 | 296 | 56 | 6 | 0 | 5 | 20 | 18 | 21 | 58 | 2.21 | 2.45 |
| Jonathan Venters | Atlanta | 66 | 5 | 4 | 58.2 | 262 | 61 | 6 | 0 | 6 | 23 | 21 | 28 | 69 | 3.22 | 3.53 | |
| Joshua Lindblom | 25 | LA Dodgers | 48 | 2 | 2 | 47.2 | 197 | 42 | 6 | 0 | 9 | 16 | 16 | 18 | 43 | 3.02 | 3.02 |
| Andrew Cashner | 26 | San Diego | 33 | 3 | 4 | 46.1 | 196 | 42 | 6 | 0 | 5 | 23 | 22 | 19 | 52 | 4.27 | 4.47 |
| Brad Ziegler | 33 | Arizona | 77 | 6 | 1 | 68.2 | 263 | 53 | 6 | 1 | 2 | 21 | 19 | 21 | 42 | 2.49 | 2.75 |
| Sergio Romo | 29 | San Francisco | 69 | 4 | 2 | 55.1 | 215 | 37 | 6 | 0 | 5 | 11 | 11 | 10 | 63 | 1.79 | 1.79 |
| Josh Beckett | 32 | LA Dodgers | 7 | 7 | 14 | 43.0 | 183 | 43 | 6 | 1 | 5 | 16 | 14 | 14 | 38 | 2.93 | 3.35 |
| Eric O'Flaherty | 27 | Atlanta | 64 | 3 | 0 | 57.1 | 230 | 47 | 6 | 0 | 3 | 14 | 11 | 19 | 46 | 1.73 | 2.20 |
| Joel Hanrahan | 31 | Pittsburgh | 63 | 5 | 2 | 59.2 | 254 | 40 | 7 | 1 | 8 | 18 | 18 | 36 | 67 | 2.71 | 2.71 |
| Craig Breslow | 32 | Arizona | 40 | 2 | 0 | 43.1 | 180 | 38 | 7 | 1 | 5 | 15 | 13 | 13 | 42 | 2.70 | 3.12 |
| Sean Marshall | 30 | Cincinnati | 73 | 5 | 5 | 61.0 | 256 | 55 | 7 | 1 | 3 | 18 | 17 | 16 | 74 | 2.51 | 2.66 |
| Brandon Beachey | Atlanta | 13 | 5 | 5 | 81.0 | 319 | 49 | 7 | 0 | 6 | 24 | 18 | 29 | 68 | 2.00 | 2.67 | |
| Kenley Jansen | 25 | LA Dodgers | 65 | 5 | 3 | 65.0 | 252 | 33 | 7 | 2 | 6 | 18 | 17 | 22 | 99 | 2.35 | 2.49 |
| Aroldis Chapman | Cincinnati | 68 | 5 | 5 | 71.2 | 276 | 35 | 7 | 1 | 4 | 13 | 12 | 23 | 122 | 1.51 | 1.63 | |
| George Kontos | 27 | San Francisco | 44 | 2 | 1 | 43.2 | 177 | 34 | 7 | 2 | 3 | 15 | 12 | 12 | 44 | 2.47 | 3.09 |
| Clay Hensley | 33 | San Francisco | 60 | 4 | 5 | 50.2 | 234 | 50 | 8 | 1 | 5 | 30 | 26 | 30 | 42 | 4.62 | 5.33 |
| Ramon Ramirez | 31 | NY Mets | 58 | 3 | 4 | 63.2 | 277 | 58 | 8 | 3 | 4 | 33 | 27 | 35 | 52 | 3.82 | 4.66 |
| Logan Ondrusek | 27 | Cincinnati | 63 | 5 | 2 | 54.2 | 243 | 51 | 8 | 0 | 8 | 23 | 21 | 31 | 39 | 3.46 | 3.79 |
| Chad Durbin | 35 | Atlanta | 76 | 4 | 1 | 61.0 | 257 | 52 | 8 | 1 | 9 | 25 | 21 | 28 | 49 | 3.10 | 3.69 |
| Jason Grilli | 36 | Pittsburgh | 64 | 1 | 6 | 58.2 | 244 | 45 | 8 | 1 | 7 | 20 | 19 | 22 | 90 | 2.91 | 3.07 |
