Something clicked in 2009. After three years as Middle Tennessee defensive coordinator, Manny Diaz was an interesting young coach who had led some minor improvements in Murfreesboro, but he was not particularly sought after; that changed in '09, when Middle Tennessee suddenly turned into a Top 20 defense. Diaz was hired away by Mississippi State and engineered an almost identical surge the next year.
| Team | Def. F/+ | S&P+ | DFEI | Succ. Rt+ |
PPP+ | Rush. S&P+ |
Pass. S&P+ |
Std. Dwns S&P+ |
Pass. Dwns S&P+ |
| Middle Tenn. 2005 (Pre-Diaz) |
N/A | 95th | N/A | 101st | 84th | 96th | 92nd | 100th | 88th |
| Middle Tenn. 2006-08 (Early Diaz) |
84th | 83rd |
87th | 76th | 88th | 75th | 89th | 83rd | 88th |
| Middle Tenn. 2009 | 20th | 23rd | 23rd | 15th | 35th | 23rd | 27th | 23rd | 33rd |
| Middle Tenn. 2010 (Post-Diaz) |
72nd | 108th | 48th | 101st | 103rd | 107th | 100th | 85th | 114th |
| Miss. State 2005-09 (Pre-Diaz) |
45th | 47th | 53rd | 44th | 50th | 37th | 60th | 40th | 49th |
| Miss. State 2010 | 7th | 10th | 10th | 17th | 12th | 10th | 21st | 7th | 14th |
Dan Mullen is a good coach and will continue to build a solid program without Diaz, but it will be interesting to see just how much of their 2010 success was due to Diaz.