If you can read a piece that ranks Georgia Tech 2nd and Georgia 59th in something without losing your shit, then Bill Connelly’s take on returning production for 2020 has some good news and some not-so-good news for us Dawg fans.
First, a reminder of what he’s measuring:
As a remedy for this, I have for a few years been deriving what I call a team’s returning production percentage as an alternative to returning starters. It looks at the most predictive key personnel stats — percentage of your QB’s passing yards returning, percentage of your secondary’s passes defensed returning, and everything in between — and is weighted based on what correlates most strongly with year-to-year improvement and regression.
In other words, he’s not saying Georgia Tech is returning the second-best team in the country; rather, he’s saying that Tech has the second-highest probability for improvement, based on returning personnel.
For offense, that means
… the following percentages create the strongest tie between returning production on offense and the following year’s improvement and regression:
• Percentage of last season’s QB passing yards returning: 32% of offensive returning production formula
• Percentage of last season’s WR/TE receiving yards returning: 32%
• Percentage of career starts returning on the offensive line: 17.5%
• Percentage of last season’s offensive line snaps returning: 12%
• Percentage of last season’s RB rushing yards returning: 6.5%
And for defense,
Because teams differ so much in their use of linemen (some teams feature three in their base defense, some four), linebackers (three to five) and defensive backs (four to five), it’s a bit trickier to derive the importance of each unit. So while I still use unit-level numbers, I also feature full-defense numbers to a degree.
• Percentage of defensive returning production formula derived from defensive line: 5%
• Percentage derived from secondary: 37%
• Percentage derived from full defense: 21%
You can probably see where the good news and bad lies in those numbers: a new quarterback is likely to hurt, but that secondary percentage is bad ass.
And bottom line, what does it mean from an advanced stats perspective?
… What does that tend to mean for a team’s SP+ ratings?
Over the past six seasons, offenses with returning production above 60% average an improvement of about two points per game, while those below regress by about three. And the extremes are pretty stark: Only one of the 18 teams that have returned at least 90% of their offensive production saw its offensive SP+ rating fall, while nine improved by at least seven adjusted points per game.
Meanwhile, of the 37 offenses that returned 35% of their production or less, only five improved, while 19 regressed by at least seven adjusted points per game.
It’s the same story on defense: Teams returning at least 85% of defensive production improve by an average of five adjusted points per game, while teams returning 40% or less regress by five adjusted points per game. If you’re on one end of the spectrum or the other, your fate is pretty settled.
Georgia returns 50% of its offensive production and 80% of its defensive production.