Overall and on average...more accurate than I would have guessed, though it obviously varies some from year to year
Year
Preseason FPI
End of Season FPI
Delta
2014
31
43
-12
2015
45
40
+5
2016
43
31
+12
2017
49
93
-44
2018
80
60
+20
2019
44
57
-13
2020
62
13
+49
2021
63
40
+23
2022
46
65
-19
2023
60
75
-15
Average
52.3
51.7
+0.6 (21.2 error)
Non-COVID Average
51.2
56
-4.7 (18.1 error)
Olympic-Style Average
51.5
51.4
+0.1 (14.9 error)
So realistically, on average we are going to finish about where FPI placed us, maybe a spot higher (depending on how much weight you give the COVID season).
Normally the error is around 15-20 spots (though equally likely in either direction) meaning that it's quite likely we fall in the 53-93 range at end of season.
The only seasons where our preseason FPI rank has been more than 20 off are 2020 (COVID), 2021 (limited 2020 data due to COVID) and 2017 (...let's just not discuss that one)