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Here’s a better way to measure 2019 college football returning production

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The teams at the top of this list are likely to improve, recent history shows. Let’s go deeper than returning starter counts.

LSU v Florida Photo by Sam Greenwood/Getty Images

My process for releasing each preseason’s S&P+ projections:

  1. Release data on the primary factors that go into the projections — returning production, recent performance, and recruiting — in individual posts. This is the first of those.
  2. Release official S&P+ projections.
  3. Begin the 130-team preview series.

February’s Signing Day is a little bit later into the month this year (February 6), so we’re going to run the preview series a bit differently. I’m going to wait until the 11th to begin the team preview series with complete recruiting data built into S&P+, and for the first week of previews, I’m releasing two previews per day.

Two-a-days as prep for football season. Get it?

That doesn’t mean we can’t go ahead and talk returning production, however.

Over the last few years, I have attempted to move beyond the too-simple “returning starters” figure to measure experience.

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.”

It’s the same with returning starters. We use it because it exists. 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?

In 2016, I began using a returning production figure based on what seems to best correlate with year-to-year performance. With what is now a few years’ worth of data, let’s take a look at some updated correlations.

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

Returning experience on the offensive line doesn’t have nearly the statistical impact that we expect. But with more data in the bank — and a new set of tweaks to S&P+ that I’ve been unveiling at Football Study Hall — we can see there’s a little correlation.

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

  • Receiving yards correlation: 0.324
  • Passing yards correlation: 0.234
  • Rushing yards correlation: 0.168
  • Offensive line starts correlation: 0.153

With more data, the offensive line correlations have begun to grow stronger, which makes sense, but 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.

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

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.

  • Defensive back tackles correlation: 0.404
  • Defensive back passes defensed correlation: 0.377
  • Overall tackles correlation: 0.325
  • Overall passes defensed correlation: 0.324
  • Defensive back tackles for loss correlation: 0.299
  • Overall tackles for loss correlation: 0.269
  • Linebacker tackles for loss correlation: 0.250
  • Linebacker tackles correlation: 0.250
  • Linebacker passes defensed correlation: 0.228

That’s right, the correlations for defensive back tackles and passes defensed is stronger than the correlations for overall tackles.

The strongest correlations on the defensive line, by the way: 0.154 for tackles, 0.119 for tackles for loss. Continuity in the trenches does not appear to be worth what we tend to think it’s worth. But continuity in the passing game, on both sides of the ball, means a ton.

One more takeaway: tackles for loss are important, but the ability to get hands on passes might be harder to replicate than any other.

So what does this mean for 2019?

As with last year, I used categories like the ones above, weighted for largest effect — so returning quarterbacks, receivers, and defensive backs carry more heft — to create numbers for offense and defense. I have updated 2018’s rosters for 2019, accounting for NFL declarations and, as much as possible (since it’s impossible to keep up with all of them), transfers.

2019 college football returning production (as of Jan. 31)

Team OFF RET Rk DEF RET Rk TOTAL RET Rk
Team OFF RET Rk DEF RET Rk TOTAL RET Rk
Western Michigan 84% 9 85% 6 85% 1
Tennessee 91% 2 76% 25 83% 2
Texas State 80% 18 85% 5 83% 3
Southern Miss 94% 1 71% 47 82% 4
Rice 76% 29 85% 4 81% 5
Florida International 85% 8 76% 26 80% 6
Memphis 79% 23 82% 12 80% 7
Kent State 86% 6 73% 34 79% 8
Hawaii 73% 34 84% 9 79% 9
Minnesota 90% 4 66% 61 78% 10
Virginia Tech 60% 77 96% 1 78% 11
Indiana 78% 25 77% 23 77% 12
Florida State 74% 33 80% 17 77% 13
Western Kentucky 81% 14 72% 39 76% 14
LSU 82% 12 70% 49 76% 15
Illinois 70% 45 81% 15 75% 16
Tulsa 71% 41 79% 19 75% 17
Ball State 66% 56 84% 10 75% 18
Georgia Southern 76% 31 74% 30 75% 19
Baylor 65% 59 85% 7 75% 20
Utah 90% 3 59% 81 75% 21
Appalachian State 87% 5 61% 77 74% 22
Oregon State 62% 73 86% 3 74% 23
Louisville 69% 49 79% 18 74% 24
Liberty 79% 19 68% 52 74% 25
Florida 77% 27 71% 43 74% 26
SMU 68% 52 79% 20 73% 27
Georgia State 73% 35 73% 32 73% 28
Wisconsin 85% 7 60% 78 73% 29
Louisiana Tech 76% 28 68% 54 72% 30
Kansas State 69% 46 75% 28 72% 31
Oregon 73% 37 71% 46 72% 32
Arizona 61% 76 82% 11 71% 33
UCLA 61% 75 81% 16 71% 34
North Carolina 81% 15 61% 76 71% 35
Cincinnati 71% 42 71% 44 71% 36
Northern Illinois 64% 61 75% 29 70% 37
South Florida 83% 11 55% 93 69% 38
UNLV 80% 17 56% 87 68% 39
Coastal Carolina 63% 69 73% 33 68% 40
Troy 59% 83 76% 24 67% 41
San Diego State 66% 57 69% 51 67% 42
Colorado 71% 44 64% 63 67% 43
Arizona State 52% 103 81% 14 66% 44
South Carolina 68% 51 64% 64 66% 45
UL-Monroe 61% 74 70% 48 66% 46
Army 80% 16 51% 102 66% 47
Michigan State 78% 24 53% 99 66% 48
Iowa 72% 39 57% 84 65% 49
UL-Lafayette 63% 70 66% 60 65% 50
Charlotte 60% 78 69% 50 65% 51
California 51% 104 78% 21 64% 52
Clemson 77% 26 52% 100 64% 53
Pittsburgh 64% 62 64% 62 64% 54
Virginia 56% 90 72% 38 64% 55
Arkansas State 53% 101 75% 27 64% 56
Oklahoma 46% 109 81% 13 64% 57
New Mexico State 79% 20 48% 109 64% 58
North Texas 79% 22 48% 110 63% 59
Connecticut 36% 125 91% 2 63% 60
Wake Forest 55% 92 72% 37 63% 61
Ohio State 42% 117 85% 8 63% 62
Alabama 67% 54 59% 80 63% 63
Syracuse 55% 93 71% 40 63% 64
BYU 69% 48 57% 85 63% 65
Nevada 71% 40 54% 98 63% 66
Temple 64% 65 61% 75 63% 67
Michigan 76% 30 50% 106 63% 68
Georgia 53% 99 72% 36 62% 69
Maryland 69% 47 56% 92 62% 70
San Jose State 63% 68 62% 72 62% 71
Northwestern 53% 97 71% 42 62% 72
Arkansas 64% 63 60% 79 62% 73
Oklahoma State 56% 91 68% 56 62% 74
Air Force 62% 72 62% 74 62% 75
Central Michigan 83% 10 40% 124 62% 76
Washington State 58% 84 64% 65 61% 77
Texas Tech 59% 82 63% 67 61% 78
USC 79% 21 43% 118 61% 79
Iowa State 53% 98 68% 53 61% 80
Missouri 54% 94 67% 57 61% 81
Houston 82% 13 39% 126 61% 82
East Carolina 65% 60 56% 91 60% 83
Auburn 54% 95 67% 59 60% 84
TCU 73% 36 47% 111 60% 85
Miami-FL 63% 67 57% 83 60% 86
Rutgers 75% 32 44% 116 60% 87
Boise State 40% 120 77% 22 59% 88
UTSA 66% 58 51% 103 59% 89
Central Florida 54% 96 63% 66 58% 90
Vanderbilt 72% 38 43% 119 58% 91
Mississippi State 59% 81 56% 90 57% 92
Nebraska 59% 79 55% 94 57% 93
Marshall 63% 66 50% 105 57% 94
Miami-OH 57% 89 57% 86 57% 95
Florida Atlantic 57% 87 56% 88 57% 96
Notre Dame 57% 86 55% 95 56% 97
Bowling Green 71% 43 42% 120 56% 98
Tulane 50% 106 63% 71 56% 99
Penn State 44% 116 68% 55 56% 100
Akron 67% 55 44% 115 55% 101
Texas A&M 62% 71 49% 108 55% 102
Purdue 37% 124 72% 35 54% 103
Utah State 46% 110 63% 68 54% 104
West Virginia 42% 118 67% 58 54% 105
Duke 37% 123 71% 45 54% 106
Toledo 50% 105 57% 82 54% 107
Stanford 45% 112 63% 70 54% 108
NC State 32% 129 74% 31 53% 109
Boston College 69% 50 38% 128 53% 110
Old Dominion 45% 113 62% 73 53% 111
Kansas 49% 107 56% 89 52% 112
Ohio 41% 119 63% 69 52% 113
Kentucky 64% 64 39% 127 51% 114
New Mexico 59% 80 43% 117 51% 115
Ole Miss 30% 130 71% 41 51% 116
Eastern Michigan 53% 100 49% 107 51% 117
Washington 67% 53 34% 130 50% 118
Georgia Tech 44% 115 55% 97 49% 119
Wyoming 52% 102 46% 113 49% 120
Texas 57% 88 40% 123 48% 121
Middle Tennessee 45% 111 51% 101 48% 122
South Alabama 44% 114 51% 104 47% 123
UTEP 58% 85 35% 129 46% 124
Colorado State 36% 126 55% 96 45% 125
Navy 47% 108 41% 122 44% 126
Buffalo 40% 122 46% 112 43% 127
Massachusetts 40% 121 45% 114 43% 128
Fresno State 34% 127 41% 121 38% 129
UAB 33% 128 39% 125 36% 130

Most of the teams near the top of the list should be in good shape.

  • Over the last five years, 35 teams have returned at least 80 percent of their production based on these calculations; 28 of them (80 percent) improved, and 17 (49 percent) improved their adjusted scoring margin per game by at least six points.
  • Last year’s top 10 teams in returning production (omitting Liberty, which was in its first year in FBS) saw their win total increase by a combined 25 games, from 45 to 70, in 2018. Michigan State regressed by three wins, and Mississippi State regressed by one. The other eight all improved.

Thus far for 2019, seven teams return 80 percent or more, including Tennessee. (I will release updated returning production figures right before the season begins.)

On the flip side, teams at the bottom might have lean years.

  • Meanwhile, 80 teams returned no more than 50 percent of their production; 65 of them (81 percent) regressed, 36 (45 percent) by at least a touchdown.
  • Last year’s bottom 10 teams saw their win total decrease by a combined 27 games, from 76 to 49. LSU and FIU each managed to improve by one win, and Colorado held steady at 5-7. The other seven all fell by at least two wins, and four (Navy, Colorado State, Louisville, and CMU) all fell by at least four.

For now, 13 teams are at 50 percent or lower, including Washington, Texas, and Georgia Tech.

SEC! SEC! SEC! SEC!

Here are 2018’s top 10 teams, according to the revamped version of S&P+, re-ranked in order of 2019 returning production:

  1. LSU (76 percent, 15th)
  2. Florida (74 percent, 26th)
  3. Clemson (64 percent, 53rd)
  4. Oklahoma (64 percent, 57th)
  5. Ohio State (63 percent, 62nd)
  6. Alabama (63 percent, 63rd)
  7. Michigan (63 percent, 68th)
  8. Georgia (62 percent, 69th)
  9. Auburn (60 percent, 84th)
  10. Mississippi State (57 percent, 92nd)

It’s safe to say Alabama will begin second in the preseason polls, and sportsbooks are listing Georgia in the top four. But there could be legitimate reason for putting four SEC teams near the top, including LSU, which overachieved last year’s returning production, and Florida. The Tigers and Gators went a combined 21-6 in 2018 and ranked fifth and ninth, respectively, in the revamped S&P+. And now they’re both going to be projected to improve by a decent amount.

In fact, if we were to use returning production as the only S&P+ projection factor — eschewing recruiting and recent history — here’s how the projected top five would take shape. Again, this would be based on nothing more than last year’s S&P+ ratings and this year’s returning production, not the complete formula:

  1. Alabama (+36.7 adjusted points per game)
  2. Georgia (+33.2)
  3. Clemson (+30.2)
  4. LSU (+28.9)
  5. Florida (+27.1)

Auburn, Mississippi State, Missouri, and Texas A&M would all be in the top 15 with this approach, too. Plus, Tennessee, second in overall returning production, could take a couple of steps forward as well.

Finally, the SEC gets its ducks in a row. (Yes, that was sarcasm.)

The year of the Ute?

Let’s keep the “If this were all there was to S&P+ projections” thing going. Here’s how the projected Pac-12 would rank based on returning production:

11. Utah
21. Washington
29. Washington State
31. Oregon
33. Stanford
36. USC

For now, never mind that there would be more Group of Five teams in the projected top 25 (Appalachian State, Memphis, and UCF) than Pac-12 teams.

Let’s just focus on the fact that Utah, which finally broke through and won the Pac-12 South, might take one final step up the ladder.

Washington could catch fire with Jacob Eason at quarterback, Oregon could break through in Mario Cristobal’s second season, USC could [insert things we say about USC every year]. But based solely on who produced for each team last year and who’s returning, Utah might start as the front-runner. We’ll see how that changes as we work recruiting rankings and whatnot into the mix.

Lowest returning production in the Power 5: guaranteed preseason top-10 Texas

121. Texas (48 percent)
119. Georgia Tech (49 percent)
118. Washington (50 percent)
116. Ole Miss (51 percent)
114. Kentucky (51 percent)
112. Kansas (52 percent)
110. Boston College (53 percent)
109. NC State (53 percent)
108. Stanford (54 percent)
106. Duke (54 percent)

Some of those, you could have guessed. Kentucky loses LB Josh Allen and most of the primary reasons for 2018’s breakthrough. Ole Miss’ offense takes a big hit. Washington loses Jake Browning, Myles Gaskin, and most of its secondary.

That top name might come as a surprise.

Fresh off of a 10-win campaign — the school’s first since 2009 — and a Sugar Bowl win, Texas is all but guaranteed to begin 2019 in the preseason top 10. The Horns bring back quarterback Sam Ehlinger and receiver Collin Johnson as headliners, plus the fruits of successful recruiting.

They do not, however, return their leading rusher (Tre Watson), leading receiver (Lil’Jordan Humphrey), three honorable mention all-conference offensive linemen, their top three tacklers on the defensive line, their top two linebackers, and three of their top five defensive backs, including corner Kris Boyd, who led the team in havoc plays (tackles for loss, forced fumbles, and passes defensed).

At 48 percent returning production, the Horns aren’t in the “guaranteed regression” range like, say, UAB and Fresno State. But Tom Herman’s recruiting classes are going to have to break through quickly if Texas is to live up to expectations.