## Five Factors: Isolating explosiveness with IsoPPP

Robert Hanashiro-USA TODAY

Efficiency and explosiveness are both incredibly important and strongly related. How should we go about measuring one without bringing in the other?

I'm really happy with the overall response to Friday's Five Factors post. I thought the post itself turned out well and conveyed the message I attempted to convey, but I think I made one mistake: I used the word "factors" too early. The point of that post and the ones that will follow was to identify the things that matter most in football, then figure out the best ways to isolate and measure them. But if I'm going to try to emulate basketball's Four Factors ... well, they were already isolated. Really, my idea of Five Factors were really five categories that might lead to factors. Semantics, really, but I had come to regret that a bit by Friday evening.

Regardless, we now set about figuring out the best ways to isolate and measure these factors as planned. And the first step might be the biggest. I can justify to you the need for both efficiency and explosiveness components, but what does that mean exactly? And how do you separate one from another?

### Why Efficiency?

#### More on Five Factors

It is rather commonly accepted at this point that Yards Per Play (i.e. explosiveness) is the single best way to measure a football team. This is a good thing; it is indeed a strong measure. But you only have a finite number of downs to rip off a big play. Unless you're going to rip off a 25-yard gain on every play, you're probably going to need to move the chains a bit if you want to score. That, of course, means you have to gain 10 yards within three (or four) plays without any major setbacks.

Simply looking at explosiveness, however you care to define it, misses this key step. Take the yardage of 20 plays from two (completely unrealistic) data sets, for instance:

Set No. 1: 80, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1
Set No. 2: 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5

In both sets, the offense gained 100 yards in 20 plays. In the first set, those 20 plays resulted in an almost certain touchdown (the 80-yard gain) and about six three-and-outs. In the second set, the offense converted on second-and-5 every single time and moved the ball at will. The median gain in Set No. 1 was one yard; in Set No. 2: five yards.

Obviously we could use Median Gain to gauge something like this. But if we stick with Success Rate (my efficiency measure of choice) for now, the question becomes this: How do we strip away explosiveness?

### IsoPPP

My first stab at this (and the point of this post) is to build off of an idea in the comments of one of my Varsity Numbers pieces at Football Outsiders.

One way of measuring this that might be useful is PPP per successful play. That might more directly get at the key question - when you have successful plays, are the REALLY successful, or just a little successful.

I liked this idea enough to pursue it. Instead of simply looking at Success Rate and PPP (Equivalent Points Per Play), what if we added together Success Rate and the PPP for only successful plays? It puts efficiency first, which isn't a surefire winner, but it frames things in an interesting way: How efficient are you, and when you're successful, how successful are you?

Using full-season game data from 2012 and 2013 (with FCS games removed), I crafted a new version of S&P using Success Rate and this Isolated PPP idea (PPP on successful plays only). The most effective weights: 86% Success Rate, 14% IsoPPP. With that weighting, I was able to almost exactly recreate the strong correlations between S&P and both points scored and percentage of points scored.

 Category Correlation with S&P (2012-13) Correlation with S&P(Iso) (2012-13) Points scored in a given game 0.754 0.768 Pct. of points scored in a given game 0.639 0.655

This new version of S&P passed another test as well. One of the better ways of determining the reliability and consistency of a measure is to compare its performance in one half of the season to its performance in the other. If the first-half and second-half numbers are drastically different, you might not be measuring a very consistent variable. Not a problem.

 Correlation with S&P Correlation with S&P(Iso) Category 1st Half of 2013 2nd Half of 2013 1st Half of 2013 2nd Half of 2013 Points scored in a given game 0.783 0.798 0.773 0.784 Pct. of points scored in a given game 0.663 0.668 0.664 0.663

This 'new' version of S&P is just as consistent and closely correlated with quality as the old one; plus, I was able to strip apart the concepts of efficiency and explosiveness to a strong degree.

Correlation between Success Rate and PPP: 0.666
Correlation between Success Rate and IsoPPP: 0.145

Now, before I go and redefine S&P+ top to bottom, I have more tests to run. I need to see how IsoPPP when adjusted for opponent, and I need to see what that does to the predictive value of S&P+. But S&P+ is a completely different story. If we're looking to gauge explosiveness and efficiency in completely different ways, this is a huge step toward doing that, no matter what impact it might have on my own ratings. (It's also far less intuitive, since you can't just quickly add two numbers together in your head.) And it completely redefines how we look at efficiency and explosiveness. In the current S&P+ formulas, I give PPP+ 60% weight and Success Rate+ 40%; in this IsoPPP world, Success Rate suddenly carries 86%.

### The rankings

To best gauge the impact of a shift from PPP to IsoPPP, let's look at some rankings. How does this new S&P data (unadjusted for opponent, mind you) take shape?

 Offense Record Success Rt Rk PPP Rk IsoPPP Rk Diff S&P(original) Rk S&P(Iso) Rk Florida State 14-0 54.5% 2 0.78 1 1.39 1 0 1.324 1 0.664 1 Texas A&M 9-4 55.5% 1 0.71 3 1.23 25 -22 1.268 2 0.649 2 Oregon 11-2 51.1% 4 0.74 2 1.38 4 -2 1.249 3 0.632 3 Ohio State 12-2 53.8% 3 0.68 5 1.20 41 -36 1.219 4 0.630 4 Alabama 11-2 51.1% 5 0.68 6 1.26 18 -12 1.190 5 0.615 5 Baylor 11-2 47.1% 21 0.70 4 1.39 2 2 1.175 6 0.600 6 Ball State 10-3 50.5% 7 0.64 15 1.18 45 -30 1.141 8 0.600 7 Auburn 12-2 49.8% 9 0.66 7 1.23 22 -15 1.153 7 0.600 8 Louisville 12-1 50.6% 6 0.62 20 1.16 57 -37 1.128 11 0.598 9 Central Florida 12-1 49.3% 13 0.63 16 1.23 20 -4 1.125 12 0.597 10 Clemson 11-2 49.2% 14 0.64 11 1.23 28 -17 1.132 9 0.595 11 Bowling Green 10-4 49.7% 10 0.62 21 1.18 46 -25 1.115 16 0.593 12 Northern Illinois 12-2 49.5% 11 0.64 13 1.17 52 -39 1.132 9 0.589 13 LSU 10-3 46.8% 22 0.65 8 1.33 8 0 1.122 13 0.588 14 Wisconsin 9-4 48.0% 19 0.64 12 1.25 19 -7 1.119 15 0.588 15 Kansas State 8-5 48.2% 18 0.63 17 1.23 21 -4 1.110 17 0.587 16 Fresno State 11-2 48.6% 17 0.64 14 1.20 39 -25 1.122 13 0.586 17 Western Kentucky 8-4 49.3% 12 0.59 26 1.12 78 -52 1.085 21 0.580 18 Indiana 5-7 45.0% 45 0.64 10 1.36 6 4 1.091 19 0.577 19 Miami-FL 9-4 44.5% 51 0.65 9 1.38 3 6 1.095 18 0.576 20 East Carolina 10-3 49.0% 16 0.58 33 1.10 84 -51 1.067 27 0.575 21 Georgia 8-5 46.2% 30 0.62 19 1.26 12 7 1.087 20 0.574 22 Toledo 7-5 49.0% 15 0.59 27 1.08 97 -70 1.081 23 0.573 23 Navy 9-4 50.2% 8 0.57 39 1.00 119 -80 1.073 25 0.572 24 San Jose State 6-6 46.6% 25 0.61 22 1.23 27 -5 1.074 24 0.572 25 Offense Record Success Rt Rk PPP Rk IsoPPP Rk Diff S&P(original) Rk S&P(Iso) Rk Missouri 12-2 45.8% 34 0.63 18 1.26 13 5 1.085 22 0.571 26 South Carolina 11-2 46.4% 29 0.61 24 1.22 30 -6 1.070 26 0.570 27 Marshall 10-4 46.7% 23 0.57 37 1.16 56 -19 1.039 32 0.564 28 Arizona State 10-4 45.7% 36 0.58 30 1.21 37 -7 1.039 32 0.563 29 New Mexico 3-9 44.9% 49 0.61 23 1.26 15 8 1.055 28 0.562 30 UL-Lafayette 9-4 46.5% 27 0.59 28 1.16 55 -27 1.051 29 0.562 31 Cincinnati 9-4 47.5% 20 0.56 46 1.09 90 -44 1.035 34 0.562 32 Boise State 8-5 46.4% 28 0.58 29 1.16 58 -29 1.047 31 0.561 33 Illinois 4-8 45.9% 32 0.56 48 1.17 49 -1 1.019 39 0.559 34 Oregon State 7-6 45.1% 42 0.58 35 1.22 33 2 1.027 36 0.559 35 Oklahoma State 10-3 45.5% 38 0.56 42 1.17 51 -9 1.019 37 0.555 36 Stanford 11-3 44.7% 50 0.60 25 1.21 34 -9 1.048 30 0.554 37 Colorado State 8-6 44.9% 47 0.58 31 1.18 43 -12 1.028 35 0.552 38 Notre Dame 9-4 44.2% 56 0.58 32 1.22 29 3 1.019 38 0.552 39 Temple 2-10 45.8% 35 0.54 57 1.12 73 -16 1.001 51 0.551 40 Troy 6-6 44.1% 57 0.58 34 1.23 24 10 1.018 41 0.551 41 Washington 9-4 45.3% 39 0.56 41 1.15 65 -24 1.018 40 0.550 42 Texas Tech 8-5 45.1% 43 0.56 50 1.16 54 -4 1.006 46 0.550 43 Georgia Tech 7-6 46.0% 31 0.54 58 1.10 85 -27 1.001 52 0.549 44 UTSA 7-5 45.6% 37 0.55 55 1.12 77 -22 1.003 49 0.549 45 Old Dominion 1-4 43.9% 60 0.56 43 1.23 25 18 1.002 50 0.549 46 UCLA 10-3 44.4% 54 0.57 40 1.19 42 -2 1.013 42 0.548 47 Ole Miss 8-5 44.5% 53 0.56 44 1.18 47 -3 1.008 45 0.548 48 Arizona 8-5 46.6% 24 0.54 61 1.04 111 -50 1.004 48 0.547 49 Duke 10-4 45.2% 40 0.56 45 1.12 74 -29 1.012 43 0.546 50 Offense Record Success Rt Rk PPP Rk IsoPPP Rk Diff S&P(original) Rk S&P(Iso) Rk South Alabama 6-6 43.7% 62 0.57 36 1.21 36 0 1.010 44 0.545 51 North Carolina 7-6 44.9% 48 0.55 56 1.13 72 -16 0.994 53 0.544 52 Mississippi State 7-6 44.2% 55 0.55 53 1.16 53 0 0.992 54 0.543 53 Wyoming 5-7 43.2% 64 0.57 38 1.22 32 6 1.004 47 0.542 54 UNLV 7-6 44.9% 46 0.52 67 1.10 86 -19 0.974 57 0.540 55 Northwestern 5-7 45.9% 33 0.51 77 1.02 114 -37 0.968 59 0.538 56 Air Force 2-10 46.5% 26 0.51 75 0.98 123 -48 0.976 56 0.537 57 Nebraska 9-4 45.1% 43 0.51 72 1.06 103 -31 0.964 61 0.536 58 North Texas 9-4 44.5% 51 0.53 65 1.06 102 -37 0.973 58 0.531 59 Army 2-10 45.2% 40 0.53 64 1.01 116 -52 0.981 55 0.530 60 Pittsburgh 7-6 43.7% 62 0.49 87 1.09 93 -6 0.929 75 0.527 61 Oklahoma 11-2 42.7% 68 0.54 60 1.15 64 -4 0.965 60 0.527 62 Maryland 7-6 38.9% 97 0.56 48 1.37 5 43 0.948 68 0.526 63 Penn State 7-5 44.0% 58 0.52 69 1.05 106 -37 0.957 63 0.526 64 Nevada 4-8 43.9% 59 0.52 68 1.06 104 -36 0.957 64 0.526 65 Michigan 7-6 41.3% 77 0.51 78 1.21 35 43 0.920 79 0.525 66 USC 10-4 41.1% 79 0.55 54 1.22 31 23 0.958 62 0.525 67 Arkansas State 8-5 43.7% 61 0.51 73 1.06 105 -32 0.950 67 0.524 68 Central Michigan 6-6 42.2% 71 0.50 79 1.15 63 16 0.926 78 0.523 69 Washington State 6-7 41.5% 75 0.52 71 1.18 44 27 0.931 74 0.523 70 Arkansas 3-9 42.9% 67 0.52 70 1.10 88 -18 0.945 70 0.523 71 BYU 8-5 41.9% 72 0.54 62 1.16 60 2 0.955 65 0.522 72 Middle Tennessee 8-5 42.6% 69 0.53 66 1.11 81 -15 0.953 66 0.522 73 Houston 8-5 39.6% 85 0.54 59 1.29 10 49 0.936 73 0.522 74 San Diego State 8-5 39.1% 95 0.55 51 1.31 9 42 0.943 71 0.520 75 Offense Record Success Rt Rk PPP Rk IsoPPP Rk Diff S&P(original) Rk S&P(Iso) Rk UAB 2-10 39.2% 94 0.54 63 1.29 11 52 0.927 76 0.518 76 Ohio 7-6 39.6% 88 0.55 52 1.26 14 38 0.946 69 0.517 77 Rutgers 6-7 40.1% 83 0.51 76 1.23 23 53 0.910 82 0.517 78 SMU 5-7 41.5% 76 0.51 74 1.14 67 7 0.927 77 0.516 79 Boston College 7-6 38.0% 106 0.56 47 1.34 7 40 0.940 72 0.514 80 Rice 10-4 41.1% 78 0.50 81 1.13 69 12 0.913 81 0.512 81 Buffalo 8-5 42.2% 70 0.48 95 1.06 101 -6 0.907 84 0.512 82 Vanderbilt 9-4 43.0% 65 0.47 102 1.01 117 -15 0.903 85 0.511 83 Tennessee 5-7 41.7% 73 0.48 96 1.08 96 0 0.901 86 0.510 84 Michigan State 13-1 41.6% 74 0.50 83 1.08 94 -11 0.913 80 0.509 85 Iowa 8-5 43.0% 66 0.48 98 0.98 124 -26 0.909 83 0.507 86 New Mexico State 2-10 40.7% 81 0.49 92 1.10 83 9 0.896 87 0.504 87 Minnesota 8-5 40.9% 80 0.48 99 1.08 99 0 0.887 92 0.502 88 Utah State 9-5 39.4% 91 0.50 84 1.15 61 23 0.891 89 0.500 89 Kentucky 2-10 39.1% 96 0.49 93 1.17 48 45 0.877 98 0.500 90 Eastern Michigan 2-10 40.2% 82 0.49 89 1.09 91 -2 0.894 88 0.499 91 Hawaii 1-11 39.5% 89 0.49 94 1.13 70 24 0.881 95 0.498 92 Florida Atlantic 6-6 39.8% 84 0.49 90 1.10 87 3 0.888 91 0.496 93 Texas 8-5 39.4% 90 0.50 86 1.11 79 7 0.890 90 0.495 94 Colorado 4-8 38.8% 99 0.49 91 1.15 62 29 0.878 97 0.494 95 Utah 5-7 36.9% 114 0.50 80 1.26 16 64 0.871 99 0.494 96 Texas State 6-6 39.6% 87 0.48 97 1.09 89 8 0.879 96 0.494 97 Kent State 4-8 39.3% 92 0.49 88 1.11 82 6 0.886 94 0.494 98 UTEP 2-10 38.7% 100 0.50 82 1.14 68 14 0.886 93 0.492 99 TCU 4-8 39.6% 85 0.47 101 1.08 98 3 0.869 100 0.492 100 Offense Record Success Rt Rk PPP Rk IsoPPP Rk Diff S&P(original) Rk S&P(Iso) Rk Akron 5-7 38.6% 101 0.47 103 1.14 66 37 0.856 104 0.492 101 California 1-11 38.2% 104 0.48 100 1.16 59 41 0.858 102 0.490 102 West Virginia 4-8 36.4% 117 0.50 84 1.26 17 67 0.861 101 0.489 103 Syracuse 7-6 39.2% 93 0.47 105 1.07 100 5 0.858 103 0.487 104 Virginia Tech 8-5 38.0% 107 0.46 106 1.12 75 31 0.842 105 0.484 105 Louisiana Tech 5-7 37.9% 108 0.46 107 1.12 76 31 0.835 107 0.483 106 UL-Monroe 6-6 37.0% 113 0.47 104 1.17 50 54 0.836 106 0.481 107 Idaho 1-11 37.6% 109 0.45 108 1.13 71 37 0.830 109 0.481 108 Iowa State 3-9 38.8% 98 0.45 111 1.05 110 1 0.833 108 0.481 109 Florida 4-8 38.5% 102 0.44 112 1.03 112 0 0.824 110 0.476 110 Memphis 3-9 38.2% 105 0.43 116 1.05 107 9 0.812 112 0.476 111 NC State 3-9 37.4% 111 0.45 110 1.09 92 18 0.822 111 0.475 112 Wake Forest 4-8 38.5% 103 0.42 118 1.02 115 3 0.802 115 0.473 113 Tulane 7-6 37.6% 110 0.43 115 1.05 109 6 0.810 113 0.470 114 Georgia State 0-12 35.0% 121 0.45 109 1.21 38 71 0.802 114 0.470 115 Connecticut 3-9 36.9% 115 0.41 119 1.05 108 11 0.775 119 0.464 116 Southern Miss 1-11 34.4% 122 0.44 113 1.20 40 73 0.780 118 0.463 117 Western Michigan 1-11 36.0% 119 0.44 114 1.08 95 19 0.796 116 0.461 118 Tulsa 3-9 37.2% 112 0.42 117 1.00 120 -3 0.792 117 0.459 119 Purdue 1-11 36.6% 116 0.39 123 0.99 121 2 0.752 121 0.453 120 Virginia 2-10 35.5% 120 0.40 120 0.98 122 -2 0.754 120 0.443 121 Massachusetts 1-11 36.0% 118 0.39 121 0.94 125 -4 0.748 122 0.442 122 Kansas 3-9 33.6% 123 0.39 122 1.03 113 9 0.723 123 0.432 123 Miami-OH 0-12 33.3% 124 0.30 126 0.85 126 0 0.636 126 0.405 124 South Florida 2-10 28.8% 126 0.37 124 1.11 80 44 0.660 124 0.403 125 Florida International 1-11 30.5% 125 0.35 125 1.00 118 7 0.653 125 0.402 126

This has the odd effect of creating drastic differences in explosiveness rankings -- Texas A&M was third in PPP but 25th in IsoPPP, while Flexboning Navy (the ultimate efficiency-only offense) went from 39th in PPP to 119th in IsoPPP -- while not really changing the overall S&P ratings. Only three teams went up more than 10 spots (Pitt and Temple because of the extra emphasis on efficiency, Michigan because of the "their big plays were uncommon and very big" effect), and none went down more than eight. Again, this is exciting. The overall ratings are pretty good and didn't need massive change; meanwhile, we've made efficiency and explosiveness two completely different variables.

 Defense Record Success Rt Rk PPP Rk IsoPPP Rk Diff S&P(original) Rk S&P(Iso) Rk Michigan State 13-1 29.1% 1 0.37 1 1.16 70 -69 0.656 1 0.412 1 Florida State 14-0 32.5% 3 0.37 2 1.03 10 -8 0.699 2 0.424 2 Virginia Tech 8-5 32.1% 2 0.41 4 1.22 97 -93 0.729 3 0.446 3 Louisville 12-1 34.2% 7 0.39 3 1.09 41 -38 0.729 4 0.447 4 USC 10-4 34.0% 6 0.42 7 1.14 62 -55 0.764 5 0.452 5 TCU 4-8 32.6% 4 0.44 12 1.23 100 -88 0.768 6 0.453 6 BYU 8-5 35.6% 9 0.44 11 1.09 40 -29 0.794 11 0.459 7 Oklahoma State 10-3 35.9% 11 0.43 8 1.08 34 -26 0.790 9 0.460 8 Iowa 8-5 37.7% 18 0.41 5 0.97 5 0 0.787 7 0.460 9 Florida Atlantic 6-6 34.5% 8 0.44 13 1.18 78 -65 0.787 8 0.461 10 Utah State 9-5 36.9% 15 0.42 6 1.05 19 -13 0.790 10 0.464 11 Wisconsin 9-4 37.8% 19 0.44 14 1.04 17 -3 0.822 15 0.471 12 East Carolina 10-3 37.9% 20 0.45 15 1.05 23 -8 0.825 18 0.473 13 North Texas 9-4 36.4% 12 0.46 22 1.14 63 -41 0.829 19 0.473 14 Alabama 11-2 37.4% 16 0.45 16 1.09 38 -22 0.824 17 0.474 15 Cincinnati 9-4 38.5% 26 0.43 9 1.02 8 1 0.816 13 0.474 16 Oregon 11-2 38.3% 25 0.46 21 1.04 13 8 0.844 21 0.475 17 Tulane 7-6 35.7% 10 0.45 18 1.21 92 -74 0.812 12 0.476 18 Clemson 11-2 34.0% 5 0.48 31 1.32 118 -87 0.819 14 0.477 19 Marshall 10-4 38.7% 29 0.45 17 1.07 29 -12 0.841 20 0.482 20 Stanford 11-3 39.0% 31 0.43 10 1.06 25 -15 0.823 16 0.483 21 Rice 10-4 36.8% 14 0.48 36 1.20 87 -51 0.853 22 0.484 22 Baylor 11-2 37.5% 17 0.48 32 1.18 83 -51 0.854 23 0.488 23 Washington 9-4 39.9% 38 0.46 20 1.05 18 2 0.859 24 0.490 24 Arizona 8-5 38.6% 27 0.49 40 1.13 59 -19 0.876 28 0.491 25 Defense Record Success Rt Rk PPP Rk IsoPPP Rk Diff S&P(original) Rk S&P(Iso) Rk Wake Forest 4-8 40.5% 43 0.48 28 1.04 15 13 0.882 31 0.495 26 Maryland 7-6 39.3% 33 0.47 23 1.12 49 -26 0.862 25 0.495 27 Florida 4-8 37.9% 21 0.49 43 1.21 93 -50 0.871 26 0.495 28 Penn State 7-5 38.6% 28 0.48 36 1.17 76 -40 0.871 27 0.496 29 Texas State 6-6 40.1% 39 0.50 49 1.10 47 2 0.897 36 0.499 30 Utah 5-7 38.0% 23 0.50 52 1.24 101 -49 0.883 32 0.499 31 Arizona State 10-4 36.5% 13 0.51 63 1.33 119 -56 0.879 29 0.500 32 Memphis 3-9 40.5% 42 0.47 27 1.08 37 -10 0.879 30 0.500 33 San Diego State 8-5 39.8% 37 0.50 51 1.13 55 -4 0.898 37 0.501 34 Louisiana Tech 5-7 41.0% 49 0.49 42 1.08 33 9 0.902 40 0.503 35 Western Kentucky 8-4 40.5% 41 0.51 56 1.12 52 4 0.913 50 0.505 36 Buffalo 8-5 38.0% 24 0.51 62 1.28 115 -53 0.894 34 0.507 37 Oklahoma 11-2 39.5% 34 0.51 59 1.20 86 -27 0.905 43 0.507 38 South Carolina 11-2 40.8% 47 0.49 41 1.12 52 -11 0.899 38 0.507 39 LSU 10-3 42.1% 56 0.47 24 1.04 15 9 0.892 33 0.508 40 Akron 5-7 40.6% 44 0.52 65 1.14 61 4 0.921 57 0.508 41 Pittsburgh 7-6 39.6% 36 0.51 54 1.20 89 -35 0.902 39 0.509 42 Houston 8-5 42.0% 55 0.49 38 1.05 21 17 0.906 45 0.509 43 Kansas State 8-5 43.2% 75 0.47 26 0.98 6 20 0.906 47 0.509 44 Connecticut 3-9 39.3% 32 0.51 60 1.23 99 -39 0.903 41 0.509 45 Boise State 8-5 42.4% 61 0.49 45 1.04 12 33 0.918 53 0.510 46 UCLA 10-3 43.9% 86 0.46 19 0.95 2 17 0.894 34 0.510 47 Colorado State 8-6 38.9% 30 0.54 78 1.26 107 -29 0.925 59 0.510 48 North Carolina 7-6 42.2% 58 0.48 34 1.06 26 8 0.904 42 0.511 49 Georgia 8-5 40.8% 46 0.52 66 1.16 69 -3 0.923 58 0.512 50 Defense Record Success Rt Rk PPP Rk IsoPPP Rk Diff S&P(original) Rk S&P(Iso) Rk Bowling Green 10-4 42.2% 59 0.48 35 1.07 30 5 0.906 46 0.512 51 Central Florida 12-1 40.4% 40 0.51 61 1.18 81 -20 0.916 52 0.513 52 Fresno State 11-2 39.6% 35 0.54 77 1.24 105 -28 0.931 64 0.514 53 Syracuse 7-6 41.2% 50 0.49 47 1.15 65 -18 0.906 47 0.515 54 Virginia 2-10 37.9% 22 0.54 80 1.36 121 -41 0.918 53 0.516 55 Missouri 12-2 42.7% 65 0.49 39 1.07 31 8 0.913 49 0.516 56 UTSA 7-5 44.1% 88 0.48 30 0.98 7 23 0.920 56 0.517 57 Vanderbilt 9-4 43.2% 74 0.47 25 1.04 14 11 0.905 44 0.517 58 Mississippi State 7-6 41.3% 51 0.52 64 1.16 71 -7 0.928 62 0.517 59 Ole Miss 8-5 43.2% 72 0.48 33 1.05 20 13 0.913 51 0.518 60 Nebraska 9-4 42.6% 62 0.49 46 1.09 39 7 0.920 55 0.519 61 South Alabama 6-6 42.0% 54 0.51 55 1.13 57 -2 0.927 60 0.520 62 Michigan 7-6 42.6% 64 0.51 53 1.09 43 10 0.932 65 0.520 63 Ohio State 12-2 42.7% 66 0.51 57 1.09 44 13 0.935 67 0.520 64 Tulsa 3-9 42.1% 57 0.52 67 1.13 57 10 0.937 68 0.521 65 Texas 8-5 41.0% 48 0.52 72 1.20 90 -18 0.934 66 0.521 66 Notre Dame 9-4 45.2% 96 0.48 29 0.96 4 25 0.931 63 0.523 67 Ohio 7-6 41.7% 52 0.55 84 1.18 82 2 0.972 78 0.524 68 Ball State 10-3 43.4% 79 0.52 68 1.08 35 33 0.951 71 0.525 69 Minnesota 8-5 42.9% 69 0.51 58 1.12 51 7 0.938 69 0.526 70 West Virginia 4-8 40.7% 45 0.56 91 1.26 111 -20 0.965 76 0.527 71 Northwestern 5-7 44.6% 93 0.49 44 1.02 9 35 0.939 70 0.527 72 South Florida 2-10 43.4% 78 0.49 48 1.10 46 2 0.928 61 0.527 73 Northern Illinois 12-2 43.6% 82 0.52 70 1.09 42 28 0.959 73 0.528 74 Texas Tech 8-5 42.9% 70 0.53 74 1.14 60 14 0.960 74 0.528 75 Defense Record Success Rt Rk PPP Rk IsoPPP Rk Diff S&P(original) Rk S&P(Iso) Rk Kansas 3-9 42.7% 67 0.53 75 1.15 64 11 0.958 72 0.528 76 Rutgers 6-7 41.8% 53 0.55 85 1.21 95 -10 0.973 79 0.529 77 Duke 10-4 44.6% 92 0.52 71 1.06 28 43 0.969 77 0.532 78 Middle Tennessee 8-5 46.6% 101 0.50 50 0.96 3 47 0.963 75 0.534 79 Boston College 7-6 43.2% 76 0.54 81 1.16 72 9 0.973 80 0.535 80 Miami-FL 9-4 44.2% 90 0.55 83 1.11 48 35 0.988 84 0.536 81 Southern Miss 1-11 44.2% 89 0.56 86 1.13 56 30 0.997 91 0.539 82 Georgia Tech 7-6 43.9% 85 0.54 79 1.16 67 12 0.977 81 0.539 83 UL-Monroe 6-6 43.5% 81 0.54 82 1.18 79 3 0.979 82 0.539 84 UNLV 7-6 43.1% 71 0.56 89 1.21 94 -5 0.987 83 0.540 85 Oregon State 7-6 42.3% 60 0.57 96 1.26 108 -12 0.996 90 0.540 86 Iowa State 3-9 43.9% 87 0.56 87 1.17 73 14 0.995 88 0.541 87 Arkansas State 8-5 43.8% 84 0.56 88 1.18 77 11 0.994 87 0.542 88 Auburn 12-2 43.3% 77 0.56 90 1.21 91 -1 0.991 85 0.542 89 Hawaii 1-11 42.8% 68 0.57 95 1.26 106 -11 0.995 89 0.544 90 NC State 3-9 43.4% 80 0.57 94 1.22 98 -4 1.001 92 0.544 91 Washington State 6-7 44.5% 91 0.58 98 1.19 84 14 1.021 95 0.549 92 Tennessee 5-7 43.2% 72 0.58 102 1.28 113 -11 1.013 94 0.550 93 Toledo 7-5 47.2% 104 0.52 69 1.03 11 58 0.992 86 0.550 94 Colorado 4-8 43.6% 82 0.59 105 1.26 110 -5 1.031 97 0.551 95 UL-Lafayette 9-4 44.8% 94 0.58 99 1.20 88 11 1.025 96 0.553 96 Western Michigan 1-11 46.9% 102 0.56 93 1.10 45 48 1.033 98 0.557 97 SMU 5-7 47.6% 107 0.53 73 1.05 22 51 1.004 93 0.557 98 Troy 6-6 42.6% 63 0.63 115 1.40 124 -9 1.060 104 0.562 99 Wyoming 5-7 47.0% 103 0.58 101 1.13 54 47 1.049 102 0.562 100 Defense Record Success Rt Rk PPP Rk IsoPPP Rk Diff S&P(original) Rk S&P(Iso) Rk Central Michigan 6-6 47.8% 108 0.56 92 1.08 36 56 1.036 99 0.563 101 Kent State 4-8 46.5% 100 0.57 97 1.17 74 23 1.038 100 0.564 102 Navy 9-4 50.6% 121 0.53 76 0.93 1 75 1.041 101 0.565 103 Texas A&M 9-4 46.2% 98 0.62 110 1.24 102 8 1.077 107 0.570 104 Georgia State 0-12 47.6% 106 0.60 106 1.16 68 38 1.076 106 0.571 105 Temple 2-10 46.3% 99 0.62 112 1.24 104 8 1.085 109 0.572 106 Florida International 1-11 45.4% 97 0.63 113 1.30 117 -4 1.084 108 0.572 107 Kentucky 2-10 48.4% 113 0.59 104 1.12 50 54 1.069 105 0.573 108 Massachusetts 1-11 47.5% 105 0.61 109 1.19 85 24 1.089 110 0.576 109 Arkansas 3-9 48.3% 111 0.58 100 1.15 66 34 1.059 103 0.576 110 San Jose State 6-6 48.2% 110 0.61 108 1.17 75 33 1.089 111 0.578 111 Illinois 4-8 47.9% 109 0.63 114 1.21 96 18 1.109 113 0.582 112 California 1-11 44.8% 95 0.68 120 1.42 126 -6 1.131 115 0.584 113 Indiana 5-7 49.4% 117 0.62 111 1.18 80 31 1.113 114 0.590 114 Army 2-10 48.5% 115 0.67 118 1.26 112 6 1.154 118 0.594 115 Purdue 1-11 51.9% 123 0.58 103 1.05 24 79 1.103 112 0.594 116 Idaho 1-11 48.3% 112 0.65 117 1.28 114 3 1.132 116 0.595 117 Nevada 4-8 49.7% 119 0.67 119 1.26 108 11 1.169 119 0.604 118 UAB 2-10 48.6% 116 0.69 121 1.34 120 1 1.172 120 0.605 119 Miami-OH 0-12 53.6% 124 0.60 107 1.06 27 80 1.137 117 0.610 120 UTEP 2-10 48.5% 114 0.72 124 1.39 123 1 1.202 122 0.611 121 New Mexico State 2-10 49.6% 118 0.73 125 1.36 122 3 1.226 124 0.617 122 Air Force 2-10 54.8% 125 0.64 116 1.07 32 84 1.187 121 0.622 123 Eastern Michigan 2-10 49.7% 119 0.74 126 1.41 125 1 1.240 125 0.625 124 New Mexico 3-9 51.8% 122 0.71 123 1.28 115 8 1.225 123 0.626 125 Old Dominion 1-4 55.0% 126 0.70 122 1.24 103 19 1.253 126 0.646 126

There is a bit more of a shift in the defensive ratings -- five teams went up at least 10 spots, and three went down at least 12 -- but nothing major. Meanwhile, we get clearer pictures of some defenses. Purdue was 123rd in Success Rate and 24th in IsoPPP (the Boilermakers' Success Rate was so bad that it made their PPP ranking 103rd), while Navy took that effect even further: 121st in Success Rate, first in IsoPPP. (Again: not adjusted for opponent.) Meanwhile, both Michigan State and Virginia Tech (along with defenses like TCU's and Clemson's) were incredibly efficient and almost never gave up big plays; but the big plays they gave up were huge ... and had little impact. Again, big plays might not have the effect we thought they had.

This is exciting!

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