+- CSNbbs (https://csnbbs.com)
+-- Forum: Active Boards (/forum-769.html)
+--- Forum: Lounge (/forum-564.html)
+---- Forum: College Sports and Conference Realignment (/forum-637.html)
+---- Thread: CFP top 15 rankings vs AP vs Massey Composite (/thread-862050.html)
CFP top 15 rankings vs AP vs Massey Composite - quo vadis - 10-31-2018 11:28 AM
Thought it might be interesting to look at how the CFP rankings compare to the top human poll and to the composite of computers.
CFP .............................. AP ........ MC
1) Alabama ................... 1 .......... 2
2) Clemson ................... 2 .......... 1
3) LSU .......................... 4 ........... 4
4) Notre Dame ............... 3 ........... 6
5) Michigan ................... 5 ........... 5
6) Georgia ..................... 6 ........... 3
7) Oklahoma .................. 7 ........... 7
8) Washington State ....... 10 .......... 16
9) Kentucky ................... 11 .......... 8
10) Ohio State ............... 8 ............ 9
11) Florida .................... 13 .......... 10
12) UCF ........................ 9 ............ 15
13) WVU ....................... 12 .......... 13
14) Penn State .............. 14 ........... 11
15) Utah ...................... 16 ............ 14
Two things stand out to me: First, humans tend to think alike. Comparing the AP and the CFP, we see that (a) both would have the same four teams in the playoffs, albeit in slightly different order. (b) The average difference between an AP ranking and the CFP ranking is just 1.0 positions. And the standard deviation is pretty tight as well - for only four teams is there even a 2 position difference, and in only once case (UCF!) is there a 3 position difference.
The computers are more different. First, Massey would have one different team in the playoffs, with Georgia replacing Notre Dame. Second, the average difference between MC and the CFP is 1.73, which is 73% greater difference than between the AP and the CFP, while the average difference between Massey and the AP is 2.2, more than twice as great as the difference between the AP and the computers.
The greatest dispersions are larger as well. E.g., comparing MC to the CFP, there is a +8 difference for Wazzu and a +3 gap for UCF and Georgia.
With the AP it's even more extreme, with gaps of +/- 3 or greater for Notre Dame, Georgia, Wazzu, Kentucky, Florida, UCF, and Penn State. That's 7 out of 15 teams with a major difference between the AP and Massey, almost half the top 15.