In Year 1, he was a complete unknown, a graduate of the prestigious Bill Belichick School of Football but someone without a track record of decision-making.

In Year 2, we had a better read on his plan, but not enough data to be 100% confident in our findings.

In Year 3, he was drafting for a new coach and a new defense, and those were wild cards we worried would gum up the mix.

But now, as we get ready for Bob Quinn’s fourth draft as Detroit Lions general manager, we have some undeniably compelling information to work with.

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► Quinn believes, beyond a shadow of a doubt, in building through the trenches. In 2016, he spent a first-round pick on an offensive lineman. In 2018, he did the same. And the one year he didn’t, he spent big on two offensive linemen in free agency.

► He values character and leadership traits, and much prefers players with high floors to the boom-or-bust ones with bigger ceilings but less chance of reaching them.

► He drafts for need. Every single first-round pick has been a Day 1 starter.

► And he loves the SEC — or at least its players — from which he’s drawn his last five first- or second-round picks. In fact, the only non-SEC player Quinn has drafted in those rounds in three years was 2016 first-round pick Taylor Decker, a product of that football factory known as The Ohio State University.

Quinn may have other preferences as general manager, but those four are pillars of his draft philosophy and the reason I gave Alabama offensive lineman Jonah Williams to the Lions in my latest trade-down mock draft.

Williams was a dominant player in the SEC for three seasons, starting for Nick Saban at right tackle as a true freshman before moving to left tackle the last two years. He’d fill one of the few starting spots the Lions still have up for grabs after free agency. And he’s considered a high-character player on and off the field. Hemay never reach the heights of a lineman like Joe Thomas, but his position versatility should lead him to a second contract with the team that drafts him.

I’ve been reluctant to give Williams to the Lions in previous versions of my mock draft because I didn’t believe the value was there at No. 8 for taking a right guard, even one who may eventually move to tackle.

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The Lions traded down a few spots in this mock and took Williams at 11, and while that isn’t that big of a drop, it somehow made the pick more palatable in my mind. The Lions aren’t passing on potential star defensive players outside of the top 10, though some would argue Florida State’s Brian Burns has that type of upside and I did have the Lions moving down with LSU’s Devin White still on the board.

I believe Quinn will do everything in his power to trade down, unless Quinnen Williams, Nick Bosa or Josh Allen somehow falls into the Lions' laps. Any one of those players would be outstanding, and there are two others — Ed Oliver and White — I think the Lions would regret passing on even if they don’t seem like perfect fits (based on size, scheme or who’s already on the roster).

Beyond that quintet, put the name of the next eight or 10 prospects in a hat and they’re about the same. Iowa tight end T.J. Hockenson is a safe pick who’d upgrade the offense, but he’s also a tight end. Burns is an athletic pass rusher, but I’m not sure how much more weight his body can carry. Clemson’s Christian Wilkins and Clelin Ferrell are versatile defensive linemen who should have long NFL careers. And Montez Sweat might be the second best defensive end in the class after Bosa, but his off-field and health concerns don’t scream "Lions."

One prospect who does is Williams, for all the reasons mentioned above.

I wrote two weeks ago that an offensive lineman was a sleeper pick for the Lions at No. 8, and I was reminded of that again when I looked back at our coverage of last year’s draft and I came upon this quote from Quinn explaining why he’s so determined to build a great offensive line.

“I think it starts in the trenches,” Quinn said last April. “I think it starts up front. I think we want to build through the middle of our team, through the offensive line, defensive line and through the middle, and that’s kind of what we believe in.”

And that’s exactly what Williams is.

Contact Dave Birkett at dbirkett@freepress.com. Follow him on Twitter @davebirkett. Read more on the Detroit Lions and sign up for our Lions newsletter.