Since the first previews of Florida’s 2019 season, the first thing to jump out at anyone who looked was the turnover at offensive line. The Gators had four departing starters, and the one returning player was not one of the best two guys in the group last year.

Spring went by without too much to say on the unit. It may not have dominated to the point of putting concerns to rest from then, but the more attention-grabbing aspect was how many true freshmen were in the second string. It was redshirt freshman Richard Gouraige and four early enrollees, though senior Noah Banks and redshirt freshman Griffin McDowell missed the session with medical issues. They’ve since returned to practice in fall camp.

It’s hard not to place an emphasis on returning starters since new players bring uncertainty. When Florida has replaced a departing senior quarterback, sometimes it’s gotten Heisman-winning Tim Tebow in 2007 and sometimes John Brantley in 2010.

There is someone who has tried to figure out where returning production matters and where it doesn’t. ESPN’s Bill Connelly, then of SB Nation, has run correlations between various stats from one year to the next. It’s the most sound attempt I’ve seen at relating individual categories for projection purposes.

For instance, on offense the highest correlation — meaning the one that provides the most predictive power — is receiving yards. The more receiving yards a team has coming back, the more likely the team is to have a good offense. The correlation isn’t exceptionally strong at 0.324 (where 0.0 means no correlation at all and 1.0 means a perfect one-to-one relationship), but it’s not hard to think of factors that could muddy the waters. An easy one is that losing a good quarterback could negate the advantage of having a lot of receivers coming back. Returning passing yards is second, by the way, with a correlation of 0.234.

The strongest correlations are on defense, where returning defensive back tackles (0.404) and returning defensive back passes defensed (0.377) beat out the returning receiving yards relationship. This makes sense considering defensive back, especially corner, is one of the hardest positions to transition in from high school to college. Even once in college, experience matters. It’s no mistake that the two worst Gator defenses of the last 20 years (2007 and 2017) had a couple of the greenest secondaries.

So what about offensive line starts returning? Its correlation is a measly 0.153. That’s barely worth mentioning. The only position with similarly low correlations happens to be on the defensive line, with returning D-line tackles (0.154) and returning tackles for loss (0.119) also being nearly useless.

Why might this be?

The defensive line isn’t so hard to figure out. Defensive tackles often have the job of eating space and blocks so others can make plays. That doesn’t tend to generate statistics. It’s entirely possible for a nose guard to have an amazing game and only wind up with one tackle in the stat sheet. His impact would be seen in tackles for other players.

Further, roles can change with personnel. Jabari Zuniga can be a good pass rusher, but last year, Jachai Polite on the other end of the line was a pass rushing monster who wasn’t as good against the run. So, last year Zuniga’s stats weren’t what they could’ve been because he was setting the edge fairly often.

This year, Jonathan Greenard is better at that kind of run defense. That fact may lead Todd Grantham to unleash Zuniga against quarterbacks. Losing Polite’s sacks and tackles for loss may be made up for by Zuniga’s stats rising.

There also is the administrative detail that UF’s 2018 roster listed Polite as a defensive lineman even though he played Buck, which is technically a linebacker spot. Greenard by contrast is listed at linebacker. If he matches Polite’s stats, it’ll be seen as a loss to the defensive line and a gain to the linebackers. The proliferation of 3-4 defenses with rush ends sometimes listed as DL and sometimes LB complicates the matter.

Like defensive tackles, offensive linemen don’t generate many stats. Some outfits like Pro Football Focus try to grade them and come up with measures like percentage of successful pass blocks, but those aren’t widely dispersed and don’t go back far in time.

Offensive line is also one of the hardest positions to recruit. Bruce Feldman wrote a lengthy piece last year on the topic, full of anecdotes about former tight ends and even former quarterbacks becoming successful offensive linemen.

Because players sometimes have to grow into their bodies to become effective linemen, they may not be ready to play there until later in their careers. Further, it’s hard to tell how much more room a lineman has to improve. An offensive tackle who looks good for a freshman in his first year on campus may still look merely good for a freshman once he becomes an upperclassman.

Plus, injuries can take a toll since the human body isn’t really made to support 300 pounds of weight among other rough realities of life in the trenches. Martez Ivey looked promising as a true freshman, but injuries, especially to his shoulder, kept him from blossoming into the surefire pro prospect his 5-star rating in high school would’ve suggested.

Put it all together, and age is probably more important than starting experience along the offensive line. Replacing a true senior with a redshirt junior as Florida is at left tackle likely isn’t a recipe for a dramatic falloff. Stone Forsythe has had plenty of time to mature physically (losing bad weight and building muscle in his case), so the Gators aren’t rolling the dice on a younger player who may or may not be there yet. He’s also played a million snaps in practice, many of them in the past 18 months with the guys who will be starting this fall thanks to four starters leaving at once.

Obviously age doesn’t explain everything. Jean Delance is a fourth-year player starting at right tackle, and no one expects him to be as good as Jawaan Taylor was in his third year on campus in 2018.

However, the line consists mostly of upperclassmen. The top five also set itself apart early, as the current starters played most or all of spring on the top line of the depth chart. John Hevesy didn’t lose much chemistry building time in March and April trying to find his best players.

Florida’s offensive line probably will be just fine this year. It may even start ahead of where 2018’s line was thanks to the players having more time in the system. The fact that only one scholarship backup is above redshirt freshman status means it can’t afford any injuries, but the starting five may not be such a concern after all. At the very least, having a relatively low number of returning starts doesn’t mean the line is guaranteed to experience a decline in quality.