The Bengals don’t draft defensive linemen in the first round under coach Marvin Lewis. The Raiders haven’t drafted a first-round offensive lineman since 2004. On the other hand, the Steelers focus on big guys. Pittsburgh has drafted six linemen or edge rushers in the past nine first rounds.

Rick Spielman has compiled his own NFL draft trends for the Vikings, whose front office has not drafted a quarterback outside the first round in a decade.

The Vikings also became one of those teams that don’t often draft offensive linemen early.

That trend is seemingly coming to an end.

With a starting spot undecided and the 30th overall pick, the Vikings could fill that hole at the start of this year’s NFL draft on Thursday night. If Spielman picks an offensive lineman in the first three rounds, it would be the first time the Vikings do so in back-to-back drafts since 2005-06, before he was hired.

The pivot really started a year ago, when the Vikings aggressively repaired the offensive line through free agency and the draft. Spielman sounds ready to start a new trend.

“Whether it be free agency or if there is an opportunity to draft one depending on who else is there on the board, of course, you try to continue to invest in the guys up front,” Spielman said this offseason.

As part of his planning, Spielman “self scouted” his own tendencies for acquiring blockers.

“On how many guys we drafted in the earlier rounds who were offensive linemen, and how aggressive we were in free agency,” Spielman said.

In the draft, what he found is the Vikings have selected only two offensive linemen — left tackle Matt Kalil No. 4 overall in 2012, center Pat Elflein in the third round last year — in the opening three rounds since 2012, when Spielman got the title of general manager.

He has selected eight offensive linemen in the fourth through seventh rounds during that span; three are still on NFL teams.

Since 2007, only one NFL team has drafted fewer first-, second- or third-round offensive linemen than the Vikings. The Jets have the fewest with two, followed by the Vikings, Cardinals, Packers and Eagles with three such picks.

Top picks obviously aren’t guaranteed hits. The Dolphins (nine), Broncos (eight), Colts (eight) and Seahawks (eight) have made the most early-round picks on offensive linemen. Today, all four teams have average or worse groups.

What’s clear is that the Vikings’ need to protect quarterback Kirk Cousins further emphasizes the rebuilding of the line, which saw more losses than additions in free agency.

“There are some very good offensive linemen in this draft,” Spielman said. “What we have to determine as we go forward now is does he fit what you require him to do?”

The need isn’t as dire as last year, when the Vikings made big-money deals for Riley Reiff and Mike Remmers. The Vikings’ interior options are fewer after Joe Berger’s retirement and Jeremiah Sirles’ exit. And two starters, left guard Nick Easton (ankle) and Elflein (shoulder/ankle), are coming off surgeries.

The draft features a “deeper” class of top interior offensive linemen, according to NFL Media analyst Mike Mayock. Spielman attended Ohio State’s pro day and talked with center/guard Billy Price. The Vikings have eyes on other options, which include a versatile guard/tackle such as Georgia’s Isaiah Wynn or a local center/guard in Chanhassen High School graduate Frank Ragnow out of Arkansas.

They have also got close looks at some top tackles, hosting Texas’ Connor Williams and reportedly Notre Dame’s Mike McGlinchey on visits.

A team’s scope is narrowed at a later first-round pick like 30th, said SiriusXM analyst Phil Savage, a former NFL executive with the Ravens, Browns and Eagles. With 29 players taken before their pick, the Vikings could be led in many directions at the end of the opening round.

“I think they’ll be surprised that a number of players they really like will be there [at No. 30],” Savage said. “Will Hernandez, the guard from UTEP. Isaiah Wynn from Georgia. If they need help at guard, those are two names to keep an eye on.”