In the world of Top-25s, I thought I posted something about success rates and such, but I guess my phone ate it. Anyway, thought it would be interesting to look at 2021's final Top-25 and where they started. (Going with AP because that's the only post top-25, though I could see a good argument for going with the pre-bowl numbers owing to how much bowls warp the final rankings). First number is final rankings, what's next is where they started.
1. 5
2. 1
3. Unranked, 32nd in total votes (2-5 in 2020 Hi Michigan)
4. 8
5. Unranked (2-7 in 2020)
6. 5
7. Unranked (1st team out, 8-3 in 2020)
8. 9
9. Unranked (2-5 in 2020)
10. 2
11. Unranked (2nd team out, 5-5 in 2020)
12. 24
13. Unranked (6-5 in 2020)
14. 3
15. Unranked (4-5 in 2020)
16. 23
17. Unranked (13th team out, 3-5 in 2020, AAC)
18. Unranked (10th team out, 4-6 in 2020)
19. Unranked (11-1 in 2020, but lost star QB, mid-major)
20. Unranked (8-4 in 2020)
21. Unranked (3-7 in 2020)
22. 11
23. 18
24. Unranked (1-5 in 2020 MWest)
25. Unranked (4-4 in 2020, West)