Coming back

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.


Filed under Georgia Football, Stats Geek!

20 responses to “Coming back

  1. W Cobb Dawg

    Considering gtu plays in the acc, moving up significantly isn’t saying much.


  2. dawgtired

    Actually, you may be safe in putting GT at #1 in probability of improving from last year. When you such that bad, there is no where but up…


  3. spur21

    Numbers – meh. Does Bill account for talented new comers? Lose an average player only to have him replaced by a future 1st round draft pick.


    • You know, it’s amazing what you can find out if you actually bother to read the linked article:

      It is a major factor in my annual SP+ projections, which will be released next week. (The other primary factors: recent recruiting and weighted five-year history.)


      (Handling transfers is a pretty clumsy process, by the way. For players on new teams, I simply include their most recent season’s production in both their new team’s numerator and denominator. It works as well as anything else I’ve tried. And for returning players who logged major stats in 2018 but missed most or all of 2019 for whatever reason, I use their 2018 stats where applicable.)


      • J-Dawg

        The only stat that is meaningful to getting production and winning games is the amount of testosterone flowing through the veins of the players, plus at least a few million active brain cells per player. You cannot qualify or quantify the motivation of the team as a whole. The rest of all this blather about stats is meaningless.


  4. David H.

    No doubt Tech will be improved. As long as they don’t improve by 45 points against us, I’ll be fine with it.

    As for Georgia, one thing the article isn’t totally clear about is the effect of incoming transfers. Obviously we’re dinged for losing Fromm’s production. But do we get credit for “returning” Newman’s Wake Forest production?


    • Will (the other one)

      That did seem a little unclear. He talked about factoring in transfers but how the production is weighted wasn’t mentioned. Considering UGA lost their top 2 rushers + several Oline starters + their top QB + 2nd, 5th, 6th, 7th, and 9th leading receivers, I think Newman is factored in a bit to the offense.


  5. Texas Dawg

    Lies, Damn Lies, and Statistic. This is truly a case of statistical gymnastics to produce a totally meaningless set of statistics. Yes they may all return (hence returning production) but if they were horrible to begin with, would you want them back even if they represented 100% of your production (but had actually produced next to ZERO in the real world compared to their peers)?

    Liked by 1 person

    • spur21

      That was my point above. I was accused of not reading but I read enough to know it is closer to what TexasDawg said than anything else. How accurate is Bill over the years when he does these projections 7 – 8 months before the season? Juggle enough numbers and you can produce any result you want.


    • “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.”

      I don’t know why this is so hard for some of you to grasp.

      If GT shows up 2nd in his preseason SP+ ratings, then you can bitch about statistics.

      Liked by 1 person

      • spur21

        More gibberish. Saying GT has the 2nd highest probability is assuming there players will get better which leaves me thinking – you can polish a turd but it still a turd – I’ll admit it might be shiny but still a turd.


        • So, you’re saying that college players don’t improve in the slightest over the course of their careers, even in cases like Georgia Tech, where there’s been a radical change in scheme.

          Sure, that seems logical.

          Liked by 1 person

  6. FlyingPeakDawg

    Bill has wayyyy too much time on his hands.

    And I still doubt tech will become the tallest dwarf to Clemson’s Cinderella.

    Liked by 1 person

  7. Biggus Rickus

    Jesus Christ. You guys do understand he’s just ranking probability of improvement, right? Tech was 109th and returns everybody. Even if their improvement is on the high end of the scale, they’ll still end up ranked in the 50s in his rankings. More modest improvement would put them in the 80s.

    Liked by 1 person

  8. JasonC

    I think some of you should just stick to “is his girlfriend beautiful or not?” and leave it at that.

    @Senator, while the post draws comparison between UGA & GT, the team I went hunting for first was Florida to see if “the gap is closing”. For those that hate math, you can stop reading here. Both UGA & Florida ranked 65%, with Florida likely improving on Offense and Georgia declining. Both improving on defense, but Georgia more so. However, if the recruiting rankings and Bill’s returning production are accurate predictors, then one would assume the gap has not closed (or at least enough for Florida to overtake UGA). But I guess, we can wait for the SP+ before arguing again.


  9. Mayor

    Pawwwwl…..If you return bad players is that a good thing? I’ll hang up and listen.