| 2012 NL Leaders | |||||||||||||||||
| Name | Age | Team | G | W | L | IP | TBF | H | 2B | 3B | HR | R | ER | BB | SO | ERA | RA9 |
| Trevor Rosenthal | St. Louis | 19 | 0 | 2 | 22.2 | 89 | 14 | 1 | 0 | 2 | 7 | 7 | 7 | 25 | 2.78 | 2.78 | |
| Alberto Cabrera | 24 | Chi Cubs | 25 | 1 | 1 | 21.2 | 99 | 16 | 4 | 1 | 1 | 15 | 13 | 18 | 27 | 5.40 | 6.23 |
| Matt Albers | 30 | Arizona | 23 | 3 | 1 | 21.0 | 84 | 16 | 0 | 0 | 3 | 7 | 6 | 7 | 19 | 2.57 | 3.00 |
| Scott Maine | Chi Cubs | 21 | 1 | 1 | 20.2 | 94 | 17 | 4 | 0 | 2 | 11 | 11 | 12 | 26 | 4.79 | 4.79 | |
| J.J. Hoover | Cincinnati | 28 | 1 | 0 | 30.2 | 123 | 17 | 3 | 1 | 2 | 7 | 7 | 13 | 31 | 2.05 | 2.05 | |
| Brandon League | 29 | LA Dodgers | 28 | 2 | 6 | 27.1 | 108 | 17 | 3 | 0 | 0 | 7 | 7 | 14 | 27 | 2.31 | 2.31 |
| Huston Street | 29 | San Diego | 40 | 2 | 1 | 39.0 | 144 | 17 | 5 | 1 | 2 | 8 | 8 | 11 | 47 | 1.85 | 1.85 |
| Tim Byrdak | 39 | NY Mets | 56 | 2 | 2 | 30.2 | 125 | 18 | 1 | 1 | 2 | 16 | 15 | 18 | 34 | 4.40 | 4.70 |
| Raul Valdes | Philadelphia | 27 | 3 | 2 | 31.0 | 113 | 18 | 1 | 0 | 3 | 10 | 10 | 5 | 35 | 2.90 | 2.90 | |
| Brian Rosenberg | Philadelphia | 22 | 1 | 2 | 25.0 | 106 | 18 | 5 | 0 | 4 | 17 | 17 | 14 | 24 | 6.12 | 6.12 | |
| Nick Vincent | San Diego | 27 | 2 | 0 | 26.1 | 105 | 19 | 3 | 0 | 2 | 5 | 5 | 7 | 28 | 1.71 | 1.71 | |
| Joshua Lindblom | 25 | Philadelphia | 26 | 3 | 5 | 23.1 | 107 | 19 | 5 | 0 | 4 | 15 | 12 | 17 | 27 | 4.63 | 5.79 |
| Henry Alberto Rodriguez | 25 | Washington | 35 | 1 | 3 | 29.1 | 131 | 19 | 2 | 0 | 4 | 20 | 19 | 22 | 31 | 5.83 | 6.14 |
| Jonathan Broxton | 28 | Cincinnati | 25 | 4 | 5 | 22.1 | 87 | 20 | 5 | 1 | 1 | 7 | 7 | 3 | 20 | 2.82 | 2.82 |
| Edward Mujica | 28 | St. Louis | 29 | 0 | 3 | 26.1 | 97 | 20 | 5 | 1 | 1 | 3 | 3 | 3 | 21 | 1.03 | 1.03 |
| Joshua Edgin | NY Mets | 34 | 1 | 2 | 25.2 | 107 | 20 | 4 | 0 | 5 | 14 | 13 | 10 | 30 | 4.56 | 4.91 | |
| Jeremy Horst | Philadelphia | 32 | 2 | 0 | 31.1 | 125 | 21 | 6 | 0 | 1 | 8 | 6 | 14 | 40 | 1.72 | 2.30 | |
| Bradley Boxberger | San Diego | 24 | 0 | 0 | 27.2 | 120 | 22 | 5 | 1 | 3 | 12 | 8 | 18 | 33 | 2.60 | 3.90 | |
| Drew Storen | Washington | 37 | 3 | 1 | 30.1 | 116 | 22 | 2 | 0 | 0 | 8 | 8 | 8 | 24 | 2.37 | 2.37 | |
| Edgar Gonzalez | 29 | Houston | 6 | 3 | 1 | 25.0 | 105 | 23 | 5 | 2 | 3 | 14 | 14 | 8 | 18 | 5.04 | 5.04 |
| Edgmer Escalona | Colorado | 22 | 0 | 1 | 22.1 | 97 | 23 | 3 | 2 | 5 | 16 | 15 | 7 | 21 | 6.05 | 6.45 | |
| Alexander Hinshaw | 30 | San Diego | 31 | 1 | 1 | 28.0 | 129 | 23 | 4 | 0 | 5 | 14 | 14 | 20 | 36 | 4.50 | 4.50 |
| Kyle McPherson | 25 | Pittsburgh | 10 | 0 | 2 | 26.1 | 107 | 24 | 3 | 0 | 3 | 8 | 8 | 7 | 21 | 2.73 | 2.73 |
| Tyler Thornburg | Milwaukee | 8 | 0 | 0 | 22.0 | 95 | 24 | 2 | 0 | 8 | 11 | 11 | 7 | 20 | 4.50 | 4.50 | |
| Guillermo Mota | 39 | San Francisco | 26 | 0 | 1 | 20.2 | 91 | 24 | 8 | 1 | 3 | 13 | 12 | 8 | 24 | 5.22 | 5.66 |
| Charles Fick | Houston | 18 | 0 | 1 | 23.0 | 107 | 24 | 4 | 1 | 4 | 13 | 11 | 17 | 17 | 4.30 | 5.09 | |
| Wily Peralta | 23 | Milwaukee | 6 | 2 | 1 | 29.0 | 113 | 24 | 4 | 0 | 0 | 8 | 8 | 11 | 23 | 2.48 | 2.48 |
| Elvin Ramirez | 25 | NY Mets | 20 | 0 | 1 | 21.1 | 102 | 24 | 7 | 1 | 1 | 13 | 13 | 20 | 22 | 5.49 | 5.49 |
| Stephen Fife | LA Dodgers | 5 | 0 | 2 | 26.2 | 115 | 25 | 3 | 0 | 2 | 8 | 8 | 12 | 20 | 2.70 | 2.70 | |
| Jim Henderson | 30 | Milwaukee | 36 | 1 | 3 | 30.2 | 131 | 25 | 3 | 1 | 1 | 12 | 11 | 13 | 45 | 3.23 | 3.52 |
