Is quarterback Mitchell Trubisky the real deal for the Chicago Bears?

The Bears have been one of the NFL's biggest surprises, and their 6-3 start has been fueled by one of the league's biggest individual surprises: the play of second-year quarterback Mitchell Trubisky.

So within the context of asking whether the Bears — who host the Vikings in a critical NFC North showdown on Sunday night — are for real, we might first ask: Is Trubisky the real deal?

First take: Michael Rand

Sorry, I'll start typing now that I've stopped rubbing my eyes to make sure they're working correctly. See, I just checked ESPN's Total QBR rankings and found Trubisky is fourth — FOURTH! — in the entire NFL. He's ahead of a lot of very good quarterbacks (including the Vikings' Kirk Cousins, who is No. 12).

That stat isn't perfect, but it's a place to start. Trubisky also has 19 touchdown passes, just seven interceptions and a 101.6 passer rating while being on pace to throw for more than 4,000 yards. Case closed?

Vikings writer Andrew Krammer: Fit him for a Hall of Fame jacket.

Jokes aside, Trubisky is an excellent example of how quarterbacks can very much be a product of the coaching and talent around them. The offseason addition the Vikings likely hated the most was Matt Nagy being hired as Bears head coach.

Rand: You might be onto something with the system thing. Pro Football Focus' QB rankings indicate Trubisky is benefiting a lot from safe throws and isn't doing much on his own. He's PFF's No. 27-ranked passer in the league this year (minimum 200 dropbacks), while Cousins comes in at No. 10. Trubisky also hasn't been a very accurate deep passer.

Give Trubisky credit so far for fitting well into Nagy's system, and give the Bears credit for playing to Trubisky's strengths. At the end of the day, though, he's probably pretty average — an upgrade over what he was last year but not the biggest of the Vikings' concerns on Sunday.

Krammer: The thing about the Bears offense is its distribution. Mike Zimmer joked Nagy installs something like "800" plays for a given game. Trubisky's top five weapons each have between 41 and 52 targets this season. While a healthy Allen Robinson might be the go-to guy, they make it difficult to game-plan for shutting down just one option.

However, regarding Trubisky, we have seen a middling athletic quarterback beat the Vikings (Josh Allen). Only Cam Newton has more rushing yards by a quarterback than Trubisky this season, and the Vikings can ill afford to underprepare for his athleticism the way Zimmer did for Allen's.

Rand: Just when I was starting to feel good about the Vikings' season, you had to remind everyone about the Buffalo game.

Ha! I think every team is capable of a dud, but man, that was a historically awful loss. I'll say the Vikings are fortunate the NFC North no longer seems to have a class system. From the Bears to the Lions (a team that beat New England), all four teams seem capable of beating anybody and losing to anybody. So, a path to a division title is clear starting Sunday night against Trubisky in Chicago.

If the Vikings can secure a home playoff game through this stretch, who knows what could happen?

More Rand: startribune.com/RandBall