| Week | Rank | Rate | Record | SOS | Opponent | Score | Rank Then | Rank Now |
| 0 | 9 | 0.000 | (0,0) | 0.000 | --bye-- |
| 1 | 518 | -0.500 | (0,1) | 0.500 | Tulane | 3 to 23 | 7 | 15 |
| 2 | 10 | 3.508 | (1,1) | 3.508 | W Illinois | 42 to 7 | 28 | 248 |
| 3 | 115 | 1.041 | (1,2) | 1.375 | Oregon | 14 to 34 | 39 | 2 |
| 4 | 166 | 0.745 | (1,2) | 1.078 | --bye-- |
| 5 | 98 | 1.197 | (2,2) | 1.197 | UCLA | 17 to 14 | 228 | 84 |
| 6 | 60 | 1.487 | (3,2) | 1.287 | ULM | 42 to 7 | 103 | 195 |
| 7 | 53 | 1.611 | (4,2) | 1.277 | Penn St | 22 to 21 | 101 | 41 |
| 8 | 42 | 1.666 | (5,2) | 1.237 | Purdue | 19 to 0 | 93 | 111 |
| 9 | 53 | 1.548 | (5,3) | 1.298 | Nebraska | 21 to 28 | 36 | 55 |
| 10 | 55 | 1.514 | (5,3) | 1.264 | --bye-- |
| 11 | 54 | 1.517 | (5,4) | 1.406 | USC | 17 to 38 | 9 | 14 |
| 12 | 56 | 1.485 | (5,5) | 1.485 | Michigan | 22 to 24 | 12 | 18 |
| 13 | 49 | 1.564 | (6,5) | 1.473 | Minnesota | 38 to 35 | 63 | 44 |
| 14 | 56 | 1.491 | (6,6) | 1.491 | Illinois | 13 to 20 | 25 | 19 |
| 15 | 55 | 1.513 | (6,6) | 1.513 | --bye-- |
| 16 | 54 | 1.515 | (6,6) | 1.515 | --bye-- |
| 17 | 52 | 1.521 | (6,6) | 1.521 | --bye-- |
| 18 | 49 | 1.578 | (7,6) | 1.502 | C Michigan | 34 to 7 | 128 | 132 |
| 19 | 48 | 1.564 | (7,6) | 1.487 | --bye-- |
| 20 | | | | | --bye-- |
| 21 | | | | | --bye-- |