Season-final Elo for all four rated units. These are the opponent-strength values every player performance against Illinois is judged with.
| Season | Rush Offense | Pass Offense | Rush Defense | Pass Defense |
|---|---|---|---|---|
| 2025 | 1440 | 1354 | 1347 | 1330 |
| 2024 | 1468 | 1330 | 1317 | 1300 |
| 2023 | 1440 | 1294 | 1321 | 1287 |
| 2022 | 1479 | 1224 | 1318 | 1311 |
| 2021 | 1455 | 1181 | 1224 | 1211 |
| 2020 | 1448 | 1181 | 1152 | 1168 |
| 2019 | 1399 | 1212 | 1180 | 1178 |
| 2018 | 1412 | 1168 | 1162 | 1194 |
| 2017 | 1238 | 1188 | 1205 | 1288 |
| 2016 | 1275 | 1228 | 1215 | 1300 |
| 2015 | 1226 | 1286 | 1298 | 1272 |
| 2014 | 1220 | 1311 | 1240 | 1179 |
| 2013 | 1310 | 1298 | 1276 | 1206 |
| 2012 | 1316 | 1179 | 1346 | 1261 |
| 2011 | 1420 | 1238 | 1419 | 1294 |
| 2010 | 1497 | 1246 | 1385 | 1234 |
| 2009 | 1415 | 1304 | 1353 | 1208 |
| 2008 | 1441 | 1290 | 1350 | 1240 |
| 2007 | 1487 | 1192 | 1315 | 1222 |
| 2006 | 1360 | 1197 | 1228 | 1260 |
| 2005 | 1312 | 1229 | 1122 | 1222 |
| 2004 | 1324 | 1256 | 1177 | 1262 |
| 2003 | 1270 | 1338 | 1225 | 1301 |
| 2002 | 1318 | 1370 | 1250 | 1332 |
| 2001 | 1297 | 1347 | 1258 | 1348 |
| 2000 | 1291 | 1287 | 1255 | 1342 |