The Mitch Trubisky solution — what took so long?

The Bears’ success since coach Matt Nagy retooled the offense to emphasize Mitch Trubisky’s strengths has been a revelation — for this franchise, anyway.

An offense that ranked 31st in scoring only four weeks ago has produced 25, 30, 34 and 33 points in consecutive games — the fifth-best total (122 points) in the NFL in that span. An offense that was last in the NFL in rushing four weeks ago has rushed for 122, 140, 169 and 199 yards since Trubisky replaced Nick Foles at quarterback. The Bears’ 157.5 -average is fourth in the NFL in that span. Their 5.6 yards per carry is second.

And Trubisky, who four weeks ago looked closer to Blake Bortles on the failed first-round quarterback scale, now is edging toward Ryan Tannehill territory — with momentum that could propel him to who knows where. Trubisky looks more like a quarterback than ever and — dare anybody say it — a potential keeper.

To critics who have been imploring Nagy to accentuate Trubisky’s strengths by moving the pocket to give him more opportunities to use his mobility and make him more of a weapon than a target, the change elicited an obvious question: What took so long?

A bit of stubbornness on Nagy’s part probably was a factor. He came here to run Andy Reid’s offense, and molding Trubisky to fit the offense was a priority over retro-fitting the offense to fit Trubisky.

And as Nagy noted, there were other moving pieces that have fallen into place to get the Bears where they are today — including a revamped offensive line with Sam Mustipher at center, Cody Whitehair at left guard and Alex Bars at right guard and the maturity of rookie tight end Cole Kmet and rookie wide receiver Darnell Mooney.

Kmet had a lot to learn. Mooney was a fifth-round pick.

“You go through these different situations throughout the course of the year, and you’re in different places at that time,” Nagy said. “Cole Kmet, we knew when we drafted him what type of player this kid is going to be. He’s going to be really, really good.

“But sometimes what’s hard for people to understand is it’s like Nintendo, and you think you can just put these kids in for the first game they ever play — or first three games they ever play — and they’re going to have these numbers or can play every snap. It’s hard to do that. So over the course of the year, you get more and more trust as coaches with a guy like Cole, and Cole gets more trust with himself.

“Even a guy like Mooney — we weren’t sure in Week 1 against Detroit, were the lights going to be too big for Mooney coming from where he came from? He’s obviously shown that they’re not.”

Of all the factors Nagy mentioned, replacing Trubisky with Nick Foles in Week 3 at Atlanta draws the most criticism. If Trubisky was running the current offense, maybe that move never would have had to be made.

“Obviously, we made the quarterback switch, so there were some things there, and I think right now . . . we try not to look back at what happened but just where we’re at right now and keep building off where we feel we’re at,” Nagy said. “And we do feel it’s a good place, with the identity of the offense, with Mitchell playing the way he’s playing, with the scheme, with the consistency of the O-line and the growth of these young players.

“Would we have loved to have it happen sooner? Yeah. But it hasn’t. So we just want to grow these next two games.”