Recently we posted our first Strength power rating, and as expected after just 3 weeks (and for most teams, only two FBS opponents), there were a lot of odd results.
Our Bayesian updates to our pre-season ratings are a lot more reliable at this point—even though it's partly based on last year's weird season—but we will compare them with the Strength power rating to see where they agree.
First, the big upward movers:
- Wyoming, up 20 to #36 for beating Ball State 45-12
- USC, up 19 to #39 after beating Washington State 45-14
- Michigan State, up 16 to #56 after winning at Miami 38-17
- Washington, up 13 to #57 after beating Arkansas State 52-3
- Georgia Tech, up 13 to #78 after almost upsetting Clemson, losing 14-8
Now let's compare lists. #1 is still Alabama; they are only #14 in the early Strength ranking. Iowa has made it all the way to #2 below, and is #10 in Strength. Oklahoma slips to #3 and is #18 in Strength. Georgia is almost a match: #4 in Bayesian and #2 in Strength!
So far what we can see going on is that our initial ranking has had an effect. The top four teams are objectively playing well—all top 20—but our prior knowledge of these teams has put them closer to where they "should" be. In other words, Strength can tell these teams are pretty good, but can't conclude that they are top level.
And there are outliers. #5 below is Wisconsin, and they are just #53 in Strength. Partly that's because they've played just two games, and also, maybe we overrated Wisconsin in our pre-season rankings. Penn State beat Wisconsin but is behind them at #6—mostly because they started at #22 and have been working their way up. They're #28 in Strength, not very good but well above Wisconsin there.
#7 Iowa State is at #24, #8 Clemson is #20, #9 Cincinnati is #16, and #10 Mississippi is #3 in Strength. So there is some correspondence, but generally 10-20 places difference. The reality probably lies somewhere in between the two rankings.
The top teams in Strength are Michigan, Georgia, Mississippi, Washington, and North Carolina. Michigan has made it up to #14 in our Bayesian ranking, so the Wolverines look legit though #1 might be quite a stretch. #2 Georgia is #4 in Bayesian and #2 in the AP poll and many other power ratings like ESPN's FPI, so that one looks accurate for both ratings. Mississippi is #10 below, and #13 in the AP so they could be a legit top ten team.
Washington's #4 rating in Strength stems from their weird season so far, which includes a huge loss to Michigan and a 49 point win over Arkansas State. It's a great example of how a small sample can make things go awry. The power rating basically "decided" that Michigan is so great that Washington's loss to them doesn't hurt the Huskies. They did move up a lot in our Bayesian rating but they're only #57. It's probably very safe to say Washington is somewhere between #4 and #57. Not very helpful, but it's hard to be accurate this early for a team with such an erratic start.
North Carolina ranks 5th in Strength and #11 below, so that's a pretty tight range. They already lost to Virginia Tech but both power ratings are saying that might have been a fluke. And since the Hokies rank #6 in Strength, it doesn't need to be much of a fluke there, but they're only #47 below, so the jury is definitely out.
Each passing week should bring the two systems closer together, until we abandon the Bayesian system altogether in about a month.
2021 Bayesian power rating update for week 3
W2 | W3 | Team | W3 Rating |
1 | 1 | Alabama | 28.88 |
3 | 2 | Iowa | 27.68 |
2 | 3 | Oklahoma | 25.66 |
4 | 4 | Georgia | 24.13 |
6 | 5 | Wisconsin | 23.30 |
7 | 6 | Penn State | 20.96 |
9 | 7 | Iowa St | 20.86 |
5 | 8 | Clemson | 20.66 |
16 | 9 | Cincinnati | 19.15 |
19 | 10 | Mississippi | 18.61 |
14 | 11 | North Carolina | 18.26 |
12 | 12 | Ohio State | 18.06 |
10 | 13 | Texas A&M | 18.03 |
20 | 14 | Michigan | 17.76 |
8 | 15 | Arizona St | 17.51 |
17 | 16 | Auburn | 16.86 |
23 | 17 | Minnesota | 15.34 |
26 | 18 | Texas | 15.31 |
18 | 19 | Indiana | 13.76 |
15 | 20 | UCLA | 13.56 |
13 | 21 | Miami FL | 12.94 |
22 | 22 | Notre Dame | 12.82 |
21 | 23 | Arkansas | 12.81 |
11 | 24 | Toledo | 12.47 |
32 | 25 | Brigham Young | 11.62 |
24 | 26 | Coastal Carolina | 11.58 |
37 | 27 | Florida | 10.89 |
30 | 28 | Western Michigan | 10.59 |
38 | 29 | Nebraska | 10.40 |
27 | 30 | Rutgers | 10.39 |
29 | 31 | Kent St | 10.31 |
39 | 32 | Louisiana-Lafayette | 10.29 |
31 | 33 | TCU | 10.13 |
46 | 34 | LSU | 9.40 |
35 | 35 | Oklahoma St | 9.28 |
56 | 36 | Wyoming | 8.78 |
34 | 37 | Maryland | 8.30 |
25 | 38 | Central Michigan | 7.75 |
58 | 39 | Southern Cal | 7.33 |
42 | 40 | Wake Forest | 6.77 |
28 | 41 | Ball St | 6.29 |
49 | 42 | Baylor | 6.13 |
48 | 43 | North Carolina St | 5.89 |
44 | 44 | Boise St | 5.72 |
50 | 45 | West Virginia | 5.43 |
36 | 46 | Miami OH | 5.42 |
45 | 47 | Virginia Tech | 5.27 |
33 | 48 | Eastern Michigan | 5.07 |
40 | 49 | Oregon | 5.06 |
41 | 50 | Appalachian St | 4.91 |
47 | 51 | Utah | 4.81 |
62 | 52 | California | 4.79 |
52 | 53 | Buffalo | 4.79 |
43 | 54 | Liberty | 4.65 |
53 | 55 | Pittsburgh | 4.56 |
72 | 56 | Michigan St | 4.33 |
70 | 57 | Washington | 4.25 |
51 | 58 | Mississippi St | 4.11 |
55 | 59 | Virginia | 3.99 |
61 | 60 | Purdue | 3.33 |
57 | 61 | Central Florida | 2.84 |
63 | 62 | San José St | 1.91 |
54 | 63 | Nevada | 1.48 |
65 | 64 | Missouri | 1.27 |
59 | 65 | Tulane | 0.88 |
77 | 66 | Kansas St | 0.69 |
60 | 67 | Northwestern | 0.54 |
66 | 68 | Troy | 0.48 |
73 | 69 | Oregon St | -0.89 |
67 | 70 | Houston | -0.92 |
76 | 71 | Louisville | -1.02 |
64 | 72 | Colorado | -1.07 |
81 | 73 | Tennessee | -1.28 |
83 | 74 | Alabama-Birmingham | -1.29 |
75 | 75 | Memphis | -1.36 |
71 | 76 | Marshall | -1.68 |
74 | 77 | Texas-San Antonio | -1.94 |
91 | 78 | Georgia Tech | -2.07 |
68 | 79 | Kentucky | -2.12 |
88 | 80 | Texas Tech | -2.49 |
79 | 81 | Boston College | -2.69 |
94 | 82 | Fresno St | -2.82 |
89 | 83 | East Carolina | -2.89 |
84 | 84 | Tulsa | -3.15 |
86 | 85 | Illinois | -3.17 |
85 | 86 | San Diego St | -3.18 |
90 | 87 | Stanford | -3.86 |
69 | 88 | Northern Illinois | -4.26 |
80 | 89 | SMU | -4.28 |
82 | 90 | Army | -5.26 |
78 | 91 | Syracuse | -5.39 |
93 | 92 | Hawai`i | -5.74 |
92 | 93 | Florida Atlantic | -6.34 |
103 | 94 | Colorado St | -6.87 |
87 | 95 | Washington St | -7.41 |
97 | 96 | Florida St | -8.91 |
95 | 97 | Ohio U. | -9.36 |
96 | 98 | Georgia St | -9.83 |
100 | 99 | South Carolina | -10.13 |
98 | 100 | Air Force | -11.76 |
101 | 101 | Middle Tennessee St | -12.01 |
104 | 102 | South Alabama | -12.24 |
107 | 103 | Utah St | -14.45 |
111 | 104 | Duke | -15.44 |
99 | 105 | Arkansas St | -15.59 |
108 | 106 | Louisiana Tech | -15.79 |
102 | 107 | Rice | -16.20 |
105 | 108 | UNLV | -17.13 |
109 | 109 | Vanderbilt | -18.40 |
106 | 110 | Texas St-San Marcos | -18.41 |
113 | 111 | Southern Miss | -18.58 |
112 | 112 | Georgia Southern | -18.74 |
115 | 113 | New Mexico | -18.85 |
118 | 114 | South Florida | -19.54 |
116 | 115 | Western Kentucky | -20.72 |
110 | 116 | Arizona | -21.04 |
114 | 117 | Florida Int'l | -21.26 |
117 | 118 | North Texas | -24.04 |
119 | 119 | UNC-Charlotte | -25.84 |
121 | 120 | Bowling Green | -26.46 |
120 | 121 | Akron | -28.05 |
123 | 122 | Navy | -28.81 |
122 | 123 | Temple | -28.82 |
124 | 124 | Kansas | -29.79 |
126 | 125 | Old Dominion | -30.23 |
125 | 126 | UTEP | -30.83 |
127 | 127 | Louisiana-Monroe | -33.83 |
128 | 128 | Massachusetts | -38.61 |
130 | 129 | Connecticut | -42.79 |
129 | 130 | New Mexico St | -42.80 |
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