| Week | Rank | Rate | Record | SOS | Opponent | Score | Rank Then | Rank Now |
| 1 | 40 | 0.000 | (0,0) | 0.000 | --bye-- |
| 2 | 29 | 0.500 | (1,0) | -0.500 | Buffalo | 38 to 17 | 424 | 231 |
| 3 | 334 | 0.905 | (1,1) | 0.905 | Washington St | 22 to 31 | 214 | 68 |
| 4 | 137 | 1.214 | (2,1) | 0.880 | Georgia Southern | 35 to 14 | 264 | 123 |
| 5 | 62 | 1.665 | (3,1) | 1.165 | Purdue | 38 to 17 | 134 | 83 |
| 6 | 36 | 1.943 | (3,1) | 1.443 | --bye-- |
| 7 | 21 | 2.143 | (4,1) | 1.543 | Rutgers | 24 to 13 | 45 | 44 |
| 8 | 26 | 1.921 | (4,2) | 1.588 | Iowa | 6 to 15 | 9 | 16 |
| 9 | 26 | 1.913 | (5,2) | 1.484 | Illinois | 25 to 21 | 70 | 73 |
| 10 | 31 | 1.888 | (5,3) | 1.638 | Ohio State | 10 to 24 | 1 | 7 |
| 11 | 41 | 1.692 | (5,4) | 1.581 | Indiana | 14 to 20 | 84 | 125 |
| 12 | 56 | 1.529 | (5,5) | 1.529 | Northwestern | 10 to 24 | 59 | 35 |
| 13 | 49 | 1.547 | (6,5) | 1.456 | Nebraska | 24 to 17 | 79 | 81 |
| 14 | 46 | 1.652 | (7,5) | 1.486 | Minnesota | 28 to 14 | 65 | 61 |
| 15 | 50 | 1.564 | (7,5) | 1.397 | --bye-- |
| 16 | 49 | 1.560 | (7,5) | 1.394 | --bye-- |
| 17 | 51 | 1.535 | (7,5) | 1.369 | --bye-- |
| 18 | 53 | 1.503 | (7,6) | 1.426 | LSU | 31 to 35 | 14 | 14 |
| 19 | | | | | --bye-- |
| 20 | | | | | --bye-- |