I don't know if you all noticed, but CalPreps updated their prediction algorithm to show the accuracy of their predictions based on past prediction accuracy:
note: here are the historical percent chances of a team winning when they have the following projected margin of victory by our system:
1: 53%
2: 57%
3: 58%
4: 60%
5: 61%
6: 62%
7: 65%
8: 72%
9: 73%
10: 74%
11: 75%
12: 77%
13: 80%
14: 81%
15: 84%
16: 86%
17: 87%
18: 87%
19: 88%
20: 88%
21: 90%
22: 92%
23: 93%
24: 94%
25: 95%
26: 95%
27: 96%
28: 96%
29: 97%
30: 97%
31: 97%
32: 98%
33: 98%
34: 98%
35: 98%
36: 99%
37 and up: >99%