In advance of Friday’s unveiling of the initial 2017 S&P+ projections, I am looking at each of three primary factors in detail. On Monday, we took a look at five-year performance averages. On Thursday, we’ll look at recruiting. Today, we’ll look at returning production, with full FBS rankings below.

Over the last couple of years, I have attempted to move beyond using the too-simple “returning starters” figure to measure experience and returning production.

We use the best tools we have, even if they're not that great. We try to derive value from offensive line starts because it's the only individual measure of offensive linemen that we have. You can't get much from "he's been one of Team A's five preferred linemen 16 times since he started school here," but the value is probably greater than zero, so we go with it. It's the same with returning starters. We use it because it exists, and nothing else is particularly available. It is fine as a really quick snapshot, but we know that one team's six returning offensive starters aren't another's. What about go-to guys? Returning backups? And quarterbacks are worth more than other starters, right?

Last year, I began using a returning production figure based on what seems to have the most direct impact on year-to-year performance. With what is now a few years’ worth of data, let’s take a look at some updated correlations between given categories and change in production.

First, we’ll take a gander at offense. Returning experience on the offensive line doesn’t have nearly the statistical impact that we think it will. But with more data in the bank, we can see there’s a little bit of a correlation.

How returning production in four different offensive stats correlates with changes in Offensive S&P+ ratings:

(The higher the number, the more likely returning production in these areas is to coincide with strong offense.)

Receiving yards correlation: 0.320

Passing yards correlation: 0.231

Rushing yards correlation: 0.126

Offensive line starts correlation: 0.096

The conclusion remains: Continuity in the passing game matters a hell of a lot, and continuity in the run game doesn’t have as strong an impact.

On defense, where returning production appears to matter more in general, the correlations are both stronger and more diverse. Since teams use different numbers of defensive linemen, linebackers, and defensive backs, I look at both unit-specific categories and those for defense as a whole.

Correlation between defensive stats and changes in Defensive S&P+:

Overall passes defensed correlation: 0.406

Overall tackles correlation: 0.369

Defensive back passes defensed correlation: 0.363

Defensive back tackles correlation: 0.352

Overall tackles for loss correlation: 0.296

Defensive back tackles for loss correlation: 0.291

Linebacker tackles for loss correlation: 0.174

Defensive line sacks correlation: 0.171

The main takeaways are similar to last year: disruption and continuity in the secondary are key. And the ability to get hands on passes, via interception or breakup, is harder to replicate than any other, when it comes to box-score disruption.

So what does this mean for 2017? As with last year, I used categories like the ones above, weighted for largest effect — so, quarterbacks, receivers, and defensive backs carry more heft — to create general “returning production” numbers for offense and defense.

2017 returning production (as of Jan. 31) Team OFF % RET Rk Proj. PPG change (Off) DEF % RET Rk Proj. PPG change (Def) % RET Rk Team OFF % RET Rk Proj. PPG change (Off) DEF % RET Rk Proj. PPG change (Def) % RET Rk FIU 85% 14 2.9 85% 6 -3.6 85% 1 TCU 92% 5 3.3 77% 23 -2.2 85% 2 Oregon 76% 37 2.3 91% 3 -4.6 84% 3 FAU 91% 8 3.3 76% 27 -2.1 83% 4 Wake Forest 97% 1 3.4 69% 49 -0.9 83% 5 Texas 84% 15 2.9 80% 12 -2.8 82% 6 Kentucky 87% 12 3.1 76% 25 -2.1 81% 7 S. Carolina 91% 7 3.3 72% 44 -1.3 81% 8 Georgia 77% 35 2.4 85% 5 -3.6 81% 9 Vanderbilt 94% 3 3.4 68% 59 -0.6 81% 10 Tulane 81% 20 2.7 80% 14 -2.7 80% 11 EMU 92% 6 3.3 69% 52 -0.8 80% 12 Indiana 63% 67 0.8 96% 1 -5.4 79% 13 Colorado St. 84% 16 2.9 74% 34 -1.7 79% 14 UMass 74% 41 2.1 84% 7 -3.4 79% 15 Miami (OH) 82% 18 2.8 75% 31 -2 79% 16 Syracuse 64% 64 1 93% 2 -5 79% 17 UTSA 81% 19 2.7 74% 33 -1.8 78% 18 SMU 94% 2 3.4 59% 81 0.9 77% 19 App. St. 80% 23 2.7 72% 43 -1.3 76% 20 Iowa St. 86% 13 3.1 65% 66 0 75% 21 Stanford 76% 38 2.3 74% 36 -1.7 75% 22 Arizona 70% 47 1.7 79% 16 -2.6 75% 23 Troy 93% 4 3.4 56% 98 1.6 74% 24 Virginia 64% 62 1 84% 8 -3.4 74% 25 USF 71% 46 1.8 77% 21 -2.2 74% 26 Penn St. 79% 26 2.6 68% 55 -0.6 74% 27 ULM 79% 28 2.5 67% 63 -0.5 73% 28 Ga. Tech 62% 70 0.7 82% 10 -3.2 72% 29 Northwestern 67% 55 1.3 77% 22 -2.2 72% 30 Missouri 89% 10 3.2 54% 102 1.9 72% 31 BGSU 74% 42 2.1 69% 53 -0.8 71% 32 Nevada 61% 73 0.5 81% 11 -2.9 71% 33 NC St. 83% 17 2.9 58% 90 1.1 71% 34 Arizona St. 72% 45 1.9 70% 48 -0.9 71% 35 Kansas St. 79% 24 2.6 61% 77 0.6 70% 36 Army 66% 56 1.2 74% 35 -1.7 70% 37 NMSU 57% 87 0 83% 9 -3.2 70% 38 Florida St. 60% 79 0.4 80% 13 -2.8 70% 39 Oregon St. 77% 36 2.3 63% 70 0.2 70% 40 MTSU 81% 22 2.7 59% 83 0.9 70% 41 BC 67% 53 1.4 72% 42 -1.3 69% 42 Wash. St. 67% 54 1.4 72% 41 -1.3 69% 43 Memphis 87% 11 3.1 51% 109 2.5 69% 44 Louisville 58% 84 0.1 80% 15 -2.7 69% 45 Rutgers 60% 76 0.4 76% 29 -2 68% 46 Texas St. 68% 51 1.4 68% 58 -0.6 68% 47 Duke 79% 25 2.6 55% 100 1.6 67% 48 Oklahoma St. 78% 30 2.5 56% 97 1.5 67% 49 Florida 81% 21 2.7 53% 103 2 67% 50 CMU 60% 78 0.4 74% 37 -1.7 67% 51 Wisconsin 66% 58 1.2 68% 56 -0.6 67% 52 Cincinnati 70% 48 1.7 64% 68 0.1 67% 53 Oklahoma 60% 77 0.4 73% 40 -1.6 67% 54 SDSU 79% 27 2.6 53% 104 2 66% 55 Auburn 72% 43 1.9 60% 79 0.8 66% 56 Wyoming 45% 103 -2.1 87% 4 -4 66% 57 Utah St. 76% 39 2.3 56% 94 1.4 66% 58 North Texas 63% 65 0.8 69% 54 -0.8 66% 59 Rice 53% 92 -0.6 78% 19 -2.5 66% 60 UNLV 90% 9 3.2 41% 117 4.2 66% 61 Purdue 55% 89 -0.3 76% 30 -2 66% 62 Miss. St. 72% 44 1.9 59% 85 0.9 65% 63 Ark. St. 78% 29 2.5 50% 111 2.5 64% 64 UTEP 57% 86 0 71% 46 -1.1 64% 65 Georgia St. 65% 59 1.2 62% 72 0.3 64% 66 Marshall 50% 96 -1.1 76% 26 -2.1 63% 67 SJSU 51% 95 -1.1 76% 28 -2.1 63% 68 Ball St. 65% 60 1.1 62% 74 0.4 63% 69 Washington 75% 40 2.2 50% 110 2.5 63% 70 USC 58% 82 0.2 67% 61 -0.6 63% 71 Ohio St. 68% 50 1.5 57% 92 1.3 63% 72 Alabama 64% 61 1 59% 84 0.9 62% 73 Texas Tech 62% 69 0.8 59% 82 0.9 61% 74 Charlotte 63% 66 0.8 59% 86 1 61% 75 So. Miss 61% 72 0.6 60% 80 0.8 61% 76 ODU 51% 94 -1 69% 51 -0.8 60% 77 Hawaii 64% 63 1 56% 99 1.6 60% 78 Buffalo 47% 98 -1.7 71% 45 -1.2 59% 79 Fresno St. 77% 34 2.4 40% 121 4.5 58% 80 Toledo 68% 52 1.4 49% 113 2.8 58% 81 California 38% 111 -3.6 78% 18 -2.5 58% 82 Kansas 78% 31 2.4 38% 122 4.8 58% 83 UCF 78% 32 2.4 38% 123 4.8 58% 84 Maryland 38% 110 -3.5 77% 24 -2.1 57% 85 Notre Dame 58% 83 0.2 56% 96 1.5 57% 86 Temple 58% 85 0.1 56% 95 1.5 57% 87 UConn 60% 75 0.5 53% 105 2 57% 88 Akron 63% 68 0.8 51% 108 2.4 57% 89 Arkansas 55% 91 -0.4 58% 89 1.1 57% 90 Minnesota 45% 102 -2 68% 60 -0.6 57% 91 Va. Tech 34% 119 -4.5 79% 17 -2.5 56% 92 Baylor 45% 104 -2.2 67% 62 -0.5 56% 93 NIU 38% 112 -3.6 74% 39 -1.6 56% 94 Boise St. 60% 74 0.5 50% 112 2.6 55% 95 Houston 51% 93 -0.9 58% 91 1.1 55% 96 UL-Laf. 40% 108 -3.2 69% 50 -0.9 54% 97 Kent St. 62% 71 0.6 47% 114 3.1 54% 98 UCLA 68% 49 1.5 40% 120 4.5 54% 99 WKU 46% 101 -1.9 62% 75 0.4 54% 100 Ohio 41% 107 -3 67% 64 -0.5 54% 101 Colorado 77% 33 2.4 29% 126 6.6 53% 102 Navy 32% 122 -5 74% 38 -1.7 53% 103 S. Alabama 46% 100 -1.9 58% 88 1.1 52% 104 Tulsa 29% 124 -5.6 75% 32 -1.9 52% 105 BYU 34% 118 -4.4 70% 47 -0.9 52% 106 Texas A&M 39% 109 -3.3 64% 67 0 52% 107 Illinois 50% 97 -1.2 53% 106 2 51% 108 Tennessee 42% 106 -2.8 61% 78 0.6 51% 109 Ole Miss 37% 115 -3.8 63% 71 0.2 50% 110 LSU 59% 80 0.3 40% 119 4.4 50% 111 Idaho 56% 88 -0.2 43% 116 3.8 50% 112 ECU 37% 113 -3.7 61% 76 0.5 49% 113 New Mexico 66% 57 1.2 33% 125 5.8 49% 114 Utah 59% 81 0.3 37% 124 4.9 48% 115 Coastal Caro. 55% 90 -0.3 41% 118 4.3 48% 116 Clemson 32% 121 -4.8 62% 73 0.4 47% 117 Iowa 27% 125 -6.2 68% 57 -0.6 47% 118 WMU 15% 129 -9.5 78% 20 -2.4 46% 119 Miami 37% 114 -3.7 55% 101 1.7 46% 120 Ga. Southern 35% 117 -4.2 57% 93 1.3 46% 121 Nebraska 26% 127 -6.3 65% 65 -0.1 46% 122 Pittsburgh 44% 105 -2.3 44% 115 3.7 44% 123 Mich. St. 35% 116 -4.2 52% 107 2.2 44% 124 La. Tech 26% 126 -6.3 59% 87 1 43% 125 N. Carolina 19% 128 -8.4 64% 69 0.1 41% 126 Michigan 46% 99 -1.8 22% 128 7.9 34% 127 WVU 30% 123 -5.3 25% 127 7.2 28% 128 Air Force 33% 120 -4.7 18% 129 8.6 25% 129

(Note: This list does not include FBS newcomer UAB, which is starting from scratch.)

How effective is it to look at returning production this way?

Over the last three years, 32 teams have returned at least 80 percent of their production based on current calculations; 26 of them improved, and 17 improved their adjusted scoring margin by more than a touchdown.

Meanwhile, 29 teams returned 45 percent of production or less; 25 of them regressed, and 15 regressed by more than a touchdown.

Thus far for 2017, 12 teams return 80 percent or more, and seven return 45 percent or less.

It's 2014 all over again.

In 2014, Oregon reached the CFP final, and TCU 12-1 and finished third in the polls. But while they went a combined 25-3 that year, they went just 10-15 last fall. A plummet to 4-8 got Oregon's Mark Helfrich fired, but he left an experienced roster for Willie Taggart.

After significant youth movements in 2016, the Ducks and Horned Frogs both return as much of last year's production as anyone in the country not named Florida International.

Another new coach hits the ground running: Texas' Tom Herman. The Longhorns are one of only three teams (along with FIU and Tulane) to return at least 80 of their production on both sides of the ball. Charlie Strong didn't leave the cupboard empty.

Return of the East?

As things stand, four SEC East teams rank among the top 10 in overall returning production: Kentucky, South Carolina, Georgia, and Vanderbilt. Plus, Missouri ranks in the top 10 in returning offense and is 31st overall.

Granted, last year's two best East teams -- Florida (15th in year-end S&P+) and Tennessee (28th) -- have some inexperience to deal with. The Gators should show gains on offense but also rank 103rd in returning defensive production, while Tennessee ranks 109th in overall production.

Still, the division as a whole should improve. It won't catch the West, but expect a little more balanced playing field in the SEC.

Woe to the Big Ten?

Michigan, Michigan State, Nebraska, and Iowa are all among the bottom 12 in returning production. The Wolverines will continue to recruit well and should get a top-15 overall projection because of it, but a step or two backward could be in the works.

In all, the Big Ten brings up the rear when it comes to average production returning.

Conference USA (65.6%) SEC (65.4%) Pac-12 (65.2%) Big 12 (64.9%) ACC (64.8%) American (62.3%) Sun Belt (61.7%) MAC (60.8%) Mountain West (60.5%) Big Ten (58.8%)

After National Signing Day, we’ll plug in the recruiting portion of this puzzle.