Hope you got to see my initial post on returning production.  I think that it is hard to make a case that a high percentage of returning production will make a championship quality team.

Look at this.  14 Teams since 2017 have increased win percentage by 50%+ and 22 have decreased their winning percentage.  Here what those two groups returned from the previous season.

As you can see, it is hard to draw a direct correlation from returning production to improved or declining winning percentage.   One team returned 80% and lost 58% more games and another returned 90% and improved 60%... I showed a similar lack of correlation in the offensive efficiency and offensive production returned.  My post centered on the Playoff Teams, but I hope you will trust me when I tell you that those team's numbers are also a fair representation of FBS teams overall.  The above chart also shows you that returning production/or lack of does not point to improved wins for the season. 

Ok, Let's look at some Defensive Returning Production from the playoff teams from 2017-2021.  First chart is the defensive success rate under Kirby Smart.  I show this as a baseline to compare the other teams we breakdown. And also, you can see the trend of the defense of the Bulldogs (hard not expect some regression - but it won't resemble a collapse)

A 2019 quality defense + what I expect is an elite offense will be a team that has to be expected to win the SEC East and compete for a playoff spot. Speaking of Playoff, let's look at some of these defenses who made the playoff.  Spoiler alert, your 2021 Georgia Bulldogs broke the returning production narrative by making the  playoff despite losing 61% of defensive from 2020.  And they again lost a significant percentage of their defense and will have to break in new players at key positions.

One thing that jumps out is that 3 teams that made playoff for the first time in the last five years (Georgia, Notre Dame, and Michigan) returned 85%, 96%, and 70% defensive production.  (those teams returned 77%, 77%, and 54% offensive production, respectively).  All of this Data is noisy considering teams a team which returned 39% of defense just won the championship. In fact, 10 of 30 allowed more yards per play despite returning 80%+ of defense, highlighted by Oregon (84%) and UNC (81%) and were supposed to compete for the playoff.

A deeper look at the defensive efficiency numbers (success rate allowed and yards per play) shows the importance of defense but also the lack of correlation of returning defensive production and improved defensive output.

Thank you for reading.  My blog will continue to free to users without a subscription for the immediate future, but please consider jumping on this intro deal.  I am posting my spreadsheet in the forum so you can look at other teams not highlighted in this post.  It includes metrics, yards, talent, and returning productions for all FBS from 2017-2021.