Football has been slower than some other sports to adapt to today's numbers-driven world. Moneyball and Sabermetrics have slowly been taking over baseball, while tempo-free statistics and other data-driven methodology have changed the way basketball is played at the college and pro levels. While football hasn't completely ignored the wealth of data the game produces, the number of coaches refusing to punt on 4th and short, or insisting that defense wins games, hasn't dwindled as quickly as many of us would like.
As anyone who reads my posts here is likely aware, I'm a huge believer in analytics in sports. With college football being my favorite sport as a fan, I decided this year to combine these passions and develop my own numbers-based ranking system for FBS level college football. I should note here that I'm hardly a trailblazing pioneer in this endeavor. Many others, perhaps most notably Bill Connelly, have been doing fantastic work at other sites, including over at SBN's own Football Study Hall, for years. In fact, I'll readily admit that what I've done here lacks some of the complexity you'll see in type of rankings published by sites like Football Outsiders.
Simply put, I don't have access to kind of data banks that larger sites are able to use. Everything you see in this article was painstakingly calculated by yours truly, using easily available basic statistics to develop something far more in depth that what you get by looking at rushing yards per game and completion percentage. I have devoted an embarrassing amount of time to this, but it is very much a beta version and a work in progress. Because I don't have access to the breadth of data available to some, I'm not able to do certain things, like eliminating garbage-time numbers, sorting efficiency numbers by down, or delving into field position data. Unfortunately, these are things that just aren't possible for me at this time, but again, I don't intend for this to be my finished product.
Methodology
My first steps in creating the formulas used here involved testing various statistics for their true value. I used the correlation coefficient to determine links between some common measures and overall team success. For those who slept through statistics, a correlation coefficient (or "r score" or "Pearson score") is a number between -1 and 1 that determines the strength of a relationship between two variables. For instance in 2013, yards gained per play and points scored per game had a CC of .8994, indicating a very strong positive relationship between the two numbers. In the other direction, points allowed per game and winning percentage had a CC of -.7933, meaning as points allowed increase, winning percentage is very likely to decrease (for obvious reasons).
I used numbers with a very high correlation to winning and scoring to develop my formulas. For my offensive rankings, a major factor is something I've referred to as "play efficiency," which is simply the percentage of plays that result in the most desired outcomes, either a first down or touchdown. The percentage of defensive plays where these outcomes are allowed factor heavily into the defensive ratings. Points scored/allowed and yards gained/allowed are also big factors.
For both offense and defense I generated a raw score based on these formulas, then adjusted for schedule using a combination of an RPI-style ranking, and the ratings for each opponent faced by each of the 126 teams. Yes, this means I sat in front of a computer and combed through the schedules of every single team in FBS to determine both the offensive and defensive strengths of schedule faced by each.
The overall ranking of a team encompasses these ratings, along with some other measures. For the KenPom crowd, "yard efficiency" and "scoring efficiency" are very similar to basketball's "efficiency margin." They are simply a team's yards gained per play minus yards allowed per play, or points scored per play minus points allowed per play.
I developed a formula using these two measures, my own offensive and defensive ratings, and few other smaller measures and adjusted for overall strength of schedule. The result is what I'm temporarily calling the Statistical Team Effectiveness Rating (super fun and creative, I know). The OSTER column indicates a team's offensive STE rating, and their offensive rank. Obviously, DSTER is the same for their defensive rating and ranking. I adjust each STE Rating such that the average rating is 100, just to provide a frame of reference when looking at the rating itself.
For right now, I'll give you my final 2013 rankings. I'll be using the same formulas to rate teams week by week moving forward, hopefully making adjustments as I go to improve the ratings. I will also make some predictive adjustments to last year's numbers and publish a set of preseason rankings later this week. Due to sample size issues, I will probably be basing the ratings for the first few weeks on the 2013 ratings, with increased weighting on 2014's early returns. So here it is, PenHawk's official 2013 college football rankings
Rank | Team | STE Rating | OSTER | Off Rank | DSTER | Def Rank | Yard Eff | Score Eff | ||
1 | Florida State | 144.0708 | 142.7951575 | 1 | 137.4969322 | 1 | 3.58 | 0.5876 | ||
2 | Alabama | 131.6819 | 132.5774113 | 3 | 126.8155657 | 4 | 2.32 | 0.3661 | ||
3 | Oregon | 129.1992 | 134.5110967 | 2 | 122.3170625 | 3 | 2.94 | 0.3519 | ||
4 | Baylor | 127.9667 | 129.8354391 | 7 | 117.3815888 | 26 | 2.73 | 0.3233 | ||
5 | Stanford | 123.8387 | 119.2198457 | 15 | 121.6739226 | 2 | 1.49 | 0.2361 | ||
6 | Missouri | 123.7250 | 124.3861138 | 9 | 116.0604949 | 8 | 1.17 | 0.2265 | ||
7 | Auburn | 123.4229 | 130.2515699 | 4 | 106.7680867 | 20 | 0.96 | 0.1957 | ||
8 | Ohio State | 123.0385 | 129.8777729 | 6 | 110.3934803 | 38 | 1.87 | 0.3187 | ||
9 | LSU | 122.3547 | 128.2257951 | 8 | 111.5932312 | 31 | 1.86 | 0.2197 | ||
10 | South Carolina | 121.6842 | 122.4971742 | 12 | 114.2691869 | 15 | 0.93 | 0.1647 | ||
11 | Clemson | 120.1411 | 118.7517753 | 16 | 116.3732507 | 23 | 1.35 | 0.1897 | ||
12 | Texas A&M | 120.0090 | 130.0648279 | 5 | 93.36750534 | 60 | 0.98 | 0.1725 | ||
13 | Wisconsin | 119.7788 | 116.3194128 | 18 | 123.8353763 | 10 | 2.12 | 0.2441 | ||
14 | Oklahoma State | 119.1151 | 115.8070863 | 19 | 121.0094802 | 9 | 1.14 | 0.2470 | ||
15 | Georgia | 118.2600 | 123.0585799 | 10 | 101.6995011 | 37 | 1.25 | 0.0868 | ||
16 | UCLA | 118.0299 | 119.3380194 | 14 | 113.6655681 | 19 | 1.01 | 0.1964 | ||
17 | Louisville | 117.9875 | 112.8585759 | 27 | 130.0267583 | 22 | 2.5 | 0.3076 | ||
18 | Michigan State | 117.1159 | 107.4436403 | 35 | 133.251836 | 5 | 1.36 | 0.1997 | ||
19 | Washington | 116.6268 | 115.7825225 | 20 | 116.3886604 | 17 | 1.37 | 0.1899 | ||
20 | Arizona State | 116.3756 | 120.0902682 | 13 | 105.2509058 | 32 | 0.28 | 0.1092 | ||
21 | Kansas State | 115.6780 | 113.6744225 | 24 | 113.1643754 | 36 | 1.24 | 0.1978 | ||
22 | USC | 114.6282 | 113.2992065 | 26 | 114.3125471 | 16 | 1.07 | 0.1351 | ||
23 | Miami (Florida) | 113.3574 | 122.9346398 | 11 | 101.7036077 | 58 | 1 | 0.1752 | ||
24 | UCF | 112.8812 | 117.3008719 | 17 | 109.0088064 | 49 | 1.21 | 0.1993 | ||
25 | Notre Dame | 112.8289 | 110.6715253 | 28 | 112.452894 | 24 | 0.95 | 0.0942 | ||
26 | Mississippi State | 112.3713 | 107.3684253 | 37 | 109.9941192 | 14 | 0.46 | 0.0176 | ||
27 | Oklahoma | 112.2024 | 114.3739476 | 23 | 108.9897364 | 34 | 0.46 | 0.1137 | ||
28 | Arizona | 111.8486 | 107.6353477 | 34 | 113.4894766 | 25 | 0.53 | 0.1049 | ||
29 | Georgia Tech | 111.5182 | 114.6498321 | 21 | 105.322236 | 45 | 0.58 | 0.1487 | ||
30 | North Carolina | 111.2603 | 105.994319 | 42 | 112.898282 | 29 | 0.59 | 0.1299 | ||
31 | Mississippi | 110.6672 | 107.3919267 | 36 | 110.4146163 | 18 | 0.79 | 0.0471 | ||
32 | Houston | 109.6100 | 101.9504871 | 54 | 117.4287333 | 30 | 0.49 | 0.1782 | ||
33 | Michigan | 109.0899 | 108.2520058 | 32 | 105.4451871 | 35 | 0.15 | 0.0872 | ||
34 | BYU | 108.8726 | 103.512978 | 51 | 119.9676407 | 13 | 0.99 | 0.0734 | ||
35 | Bowling Green | 108.6478 | 105.8846799 | 43 | 117.540379 | 40 | 1.48 | 0.2453 | ||
36 | Iowa | 108.5563 | 98.94068884 | 66 | 121.9602771 | 7 | 0.68 | 0.0820 | ||
37 | Utah | 107.9828 | 105.5129788 | 45 | 106.6900479 | 28 | 0.13 | 0.0263 | ||
38 | Cincinnati | 107.9786 | 104.0375836 | 49 | 108.6537868 | 79 | 1.46 | 0.1063 | ||
39 | Duke | 106.8735 | 109.9156017 | 29 | 102.4917943 | 57 | 0.2 | 0.0913 | ||
40 | Northern Illinois | 106.4203 | 109.1472128 | 31 | 104.8296763 | 83 | 1.33 | 0.1873 | ||
41 | Nebraska | 106.0335 | 105.8634885 | 44 | 107.1921317 | 50 | 0.36 | 0.0829 | ||
42 | Virginia Tech | 106.0139 | 94.117201 | 80 | 120.4697907 | 6 | 0.47 | 0.0078 | ||
43 | Utah State | 105.8198 | 94.75404364 | 78 | 124.7581534 | 11 | 0.82 | 0.1802 | ||
44 | Oregon State | 105.3010 | 113.5702076 | 25 | 91.24225222 | 84 | 0.05 | 0.0194 | ||
45 | East Carolina | 105.1869 | 107.0999044 | 39 | 108.2641823 | 52 | 1.02 | 0.1785 | ||
46 | Marshall | 105.0270 | 101.0281297 | 57 | 111.822918 | 61 | 1.51 | 0.2353 | ||
47 | Pittsburgh | 104.7064 | 102.8487702 | 53 | 101.2549285 | 47 | 0 | -0.0078 | ||
48 | TCU | 104.4211 | 93.51583368 | 83 | 114.9955718 | 21 | 0.2 | 0.0235 | ||
49 | Boston College | 104.1520 | 106.8080977 | 41 | 97.6469829 | 64 | 0.12 | 0.0559 | ||
50 | Toledo | 104.0925 | 103.4525434 | 52 | 96.62328403 | 77 | 0.55 | 0.0753 | ||
51 | Vanderbilt | 104.0866 | 107.2979298 | 38 | 105.3515826 | 51 | 0.34 | 0.0925 | ||
52 | Texas Tech | 104.0740 | 106.9668169 | 40 | 101.5331789 | 59 | 0.49 | 0.0191 | ||
53 | Boise State | 103.8143 | 99.71641424 | 61 | 109.0593643 | 53 | 0.76 | 0.1591 | ||
54 | Texas | 103.4550 | 100.0005288 | 60 | 107.4819795 | 33 | -0.19 | 0.0319 | ||
55 | Fresno State | 102.8600 | 107.9418718 | 33 | 97.35012627 | 88 | 0.88 | 0.1209 | ||
56 | Maryland | 102.7276 | 100.308459 | 59 | 109.0673565 | 55 | 0.69 | 0.0383 | ||
57 | Washington State | 102.5973 | 104.1701458 | 47 | 96.85239738 | 56 | -0.44 | -0.0166 | ||
58 | Navy | 102.5576 | 103.5378461 | 50 | 101.5944303 | 63 | 0.16 | 0.1241 | ||
59 | Indiana | 102.5229 | 114.4510678 | 22 | 80.29426881 | 101 | -0.16 | 0.0014 | ||
60 | Penn State | 102.1672 | 99.56761259 | 62 | 106.0781735 | 41 | 0.41 | 0.0141 | ||
61 | Minnesota | 102.0343 | 99.22736931 | 65 | 107.1231471 | 42 | -0.43 | 0.0552 | ||
62 | Florida | 101.9058 | 91.72973827 | 88 | 111.3924657 | 12 | -0.51 | -0.0706 | ||
63 | North Texas | 101.6526 | 95.23295279 | 74 | 116.6209859 | 43 | 0.47 | 0.1727 | ||
64 | Northwestern | 101.6043 | 96.85897744 | 67 | 105.7157292 | 46 | -0.07 | 0.0035 | ||
65 | Ball State | 101.1582 | 104.5485395 | 46 | 102.4837789 | 94 | 0.88 | 0.1897 | ||
66 | Tennessee | 100.6877 | 101.2320978 | 55 | 95.66142 | 48 | -0.8 | -0.0651 | ||
67 | Syracuse | 99.5969 | 96.08652148 | 73 | 106.0589145 | 44 | -0.23 | -0.0609 | ||
68 | Louisiana-Lafayette | 98.3852 | 104.1064398 | 48 | 95.22049607 | 100 | 0.39 | 0.1092 | ||
69 | Tulane | 98.0783 | 86.45775094 | 102 | 115.2819689 | 39 | -0.25 | 0.0716 | ||
70 | South Alabama | 97.5300 | 94.78931129 | 77 | 101.7121204 | 71 | 0.17 | 0.0314 | ||
71 | Western Kentucky | 97.4769 | 99.23947885 | 64 | 100.0396414 | 87 | 0.96 | 0.0360 | ||
72 | UTSA | 96.8307 | 96.25807363 | 72 | 99.38613598 | 73 | 0.61 | -0.0089 | ||
73 | Arkansas | 96.7778 | 96.32294534 | 71 | 90.2725766 | 65 | -0.56 | -0.1341 | ||
74 | Arkansas State | 96.5258 | 94.93460431 | 76 | 100.6577057 | 69 | -0.18 | 0.0336 | ||
75 | Illinois | 96.3972 | 109.2360608 | 30 | 80.69818442 | 109 | -0.75 | -0.0789 | ||
76 | San Jose State | 96.3799 | 101.1127338 | 56 | 84.81314891 | 104 | 0.24 | -0.0499 | ||
77 | Florida Atlantic | 95.8939 | 89.25444694 | 96 | 109.7162516 | 54 | 0.43 | 0.0376 | ||
78 | Rice | 95.2060 | 91.90835707 | 87 | 104.7171136 | 62 | 0.1 | 0.0398 | ||
79 | Middle Tennessee | 95.0920 | 94.94765997 | 75 | 104.908902 | 74 | 0.38 | 0.0607 | ||
80 | Wake Forest | 95.0686 | 83.69599171 | 106 | 112.9947408 | 27 | -0.63 | -0.0547 | ||
81 | Colorado | 95.0108 | 96.79245917 | 68 | 86.79744021 | 96 | -0.74 | -0.1308 | ||
82 | Kentucky | 94.5460 | 94.33526229 | 79 | 90.16624988 | 75 | -0.97 | -0.1393 | ||
83 | West Virginia | 94.4896 | 96.40633653 | 70 | 94.47453433 | 81 | -0.39 | -0.0792 | ||
84 | Colorado State | 94.4128 | 100.3463792 | 58 | 92.40849153 | 105 | 0.53 | 0.0702 | ||
85 | San Diego State | 93.5576 | 90.00813894 | 92 | 95.19726565 | 91 | 0.42 | -0.0334 | ||
86 | Memphis | 93.1897 | 83.14135533 | 110 | 107.7411979 | 78 | -0.51 | -0.0516 | ||
87 | Buffalo | 93.1315 | 92.90061864 | 85 | 101.6008339 | 85 | -0.27 | 0.0519 | ||
88 | Rutgers | 92.8068 | 93.20106671 | 84 | 95.43774188 | 82 | -0.39 | -0.0258 | ||
89 | UNLV | 91.7867 | 94.05236162 | 81 | 92.94631131 | 97 | -0.34 | -0.0285 | ||
90 | North Carolina State | 91.4995 | 87.9943252 | 97 | 93.3044132 | 72 | -0.77 | -0.1553 | ||
91 | Ohio | 91.0555 | 91.07216929 | 90 | 96.06679148 | 95 | -0.19 | 0.0119 | ||
92 | Iowa State | 90.7296 | 91.27683954 | 89 | 89.60519932 | 92 | -1.23 | -0.1406 | ||
93 | Temple | 90.5502 | 89.97811822 | 93 | 92.60945695 | 98 | -0.7 | -0.0463 | ||
94 | SMU | 90.3331 | 93.957797 | 82 | 89.29183176 | 102 | -0.05 | -0.1108 | ||
95 | Kent State | 90.1530 | 87.4140346 | 99 | 94.64174342 | 90 | -0.5 | -0.0846 | ||
96 | Akron | 89.7487 | 83.24687846 | 108 | 98.64271994 | 67 | -0.61 | -0.1076 | ||
97 | Louisiana-Monroe | 89.1252 | 86.72711863 | 101 | 95.25149998 | 80 | -0.79 | -0.1014 | ||
98 | Virginia | 89.0755 | 83.62444295 | 107 | 94.87725159 | 66 | -1.22 | -0.2286 | ||
99 | Troy | 89.0057 | 99.39536439 | 63 | 77.41792696 | 114 | -0.63 | -0.0512 | ||
100 | Texas State | 87.9514 | 83.82726875 | 105 | 101.3816033 | 89 | -0.33 | 0.0000 | ||
101 | Connecticut | 87.7036 | 83.1422826 | 109 | 95.57849898 | 86 | -0.9 | -0.1359 | ||
102 | Hawai'i | 86.8381 | 84.7022016 | 104 | 87.84525124 | 93 | -0.7 | -0.1210 | ||
103 | Tulsa | 86.6078 | 80.48852942 | 113 | 95.70212437 | 70 | -0.85 | -0.1586 | ||
104 | Wyoming | 86.3389 | 92.8358264 | 86 | 84.23108247 | 111 | 0.16 | -0.0492 | ||
105 | South Florida | 85.7926 | 75.28681619 | 122 | 95.22910977 | 68 | -1.12 | -0.2109 | ||
106 | Central Michigan | 85.6753 | 87.07842114 | 100 | 91.01000568 | 108 | -0.44 | -0.0439 | ||
107 | Nevada | 85.5680 | 89.75228315 | 95 | 79.30919859 | 106 | -1.83 | -0.1529 | ||
108 | Kansas | 83.8610 | 77.7702784 | 118 | 94.33504 | 76 | -1.53 | -0.2053 | ||
109 | Purdue | 82.2019 | 80.04077635 | 114 | 80.64374503 | 99 | -1.67 | -0.2744 | ||
110 | California | 82.1596 | 90.4143897 | 91 | 65.87160757 | 115 | -1.88 | -0.3495 | ||
111 | New Mexico | 81.3446 | 96.65537859 | 69 | 56.83280415 | 121 | -0.93 | -0.1119 | ||
112 | Louisiana Tech | 80.8595 | 79.38327629 | 116 | 101.4299859 | 103 | -0.18 | -0.0731 | ||
113 | Air Force | 79.5739 | 85.42001143 | 103 | 72.03038367 | 116 | -0.97 | -0.1579 | ||
114 | Army | 78.5399 | 87.81022694 | 98 | 75.99262024 | 117 | -1.06 | -0.1577 | ||
115 | Western Michigan | 77.9472 | 76.75671973 | 119 | 83.36576342 | 107 | -1.07 | -0.2420 | ||
116 | UAB | 77.5103 | 89.97574715 | 94 | 56.58861877 | 122 | -1.37 | -0.2442 | ||
117 | Georgia State | 73.0429 | 78.71607349 | 117 | 83.53953373 | 110 | -0.92 | -0.2126 | ||
118 | Idaho | 72.5398 | 76.72184974 | 120 | 63.76667081 | 120 | -2.12 | -0.3765 | ||
119 | Southern Mississippi | 72.0775 | 75.83508453 | 121 | 71.64695781 | 118 | -1.25 | -0.3149 | ||
120 | Massachusetts | 71.8605 | 70.27910099 | 123 | 78.8036591 | 113 | -2.31 | -0.3246 | ||
121 | New Mexico State | 70.3944 | 82.29556907 | 111 | 57.25061763 | 123 | -2.23 | -0.3259 | ||
122 | Eastern Michigan | 67.7945 | 80.87043441 | 112 | 51.6764454 | 125 | -2.45 | -0.3844 | ||
123 | UTEP | 66.8687 | 80.03515272 | 115 | 55.3463258 | 124 | -2.37 | -0.3074 | ||
124 | Miami (Ohio) | 66.8655 | 64.16666337 | 124 | 81.15731425 | 112 | -2.67 | -0.3094 | ||
125 | Florida International | 64.2805 | 63.53084454 | 125 | 70.15116083 | 119 | -2.96 | -0.4078 |
I know how incredibly dry this is for many of you, so I appreciate you reading through this. Like I said at the beginning, this is very much a work in progress. I welcome any questions about my methodology, and definitely welcome any suggestions for improvement, so if anything jumps off the page and looks off, please let me know in the comments section and we can discuss it. You can also shoot me an e-mail with any questions or suggestions. Believe it or not, this stuff is a lot of fun for me, and I'd like nothing more than to eventually turn this into something bigger and much more useful
Questions? Comments? Please e-mail me at PenHawkRCT@gmail.com. You can also follow me on Twitter @kspen124