As we approach Sunday’s NFC Championship Game between the 49ers and Packers, there’s a big, glaring mismatch that I don’t believe we’re talking about enough.

No, it’s not George Kittle vs. Packers linebacker Blake Martinez, or Nick Bosa’s power rush against Green Bay left tackle David Bakhtiari.

It’s not even between the lines on the field.

It’s the showdown of head coaches.

We know that 49ers’ head coach Kyle Shanahan is one of the best in the NFL, if for no other reason than the fact that he’s arguably the best offensive coordinator in the league.

But are we sure that Packers first-year coach Matt LaFleur is anywhere near Shanahan’s level?

I’m not.

Yes, LaFleur’s team went 13-3 — now 14-3 — this campaign, but there’s no evidence to suggest that the man who is in his second season as an NFL play-caller was really the difference between the team not making the playoffs in 2018 and being in the NFC Championship Game this season.

(Kyle Shanahan, also 40 years old, has 12 years of experience calling plays at an NFL level.)

To be fair, it’s tough to judge LaFleur’s play-calling, because quarterback Aaron Rodgers so often changes the play at the line of scrimmage. But the data more than suggests that once the Packers have to go off script — when LaFleur has to think on his feet — they struggle.

And that’s bad news for Green Bay with a trip to the Super Bowl on the line Sunday. Related Articles What we learned Friday at 49ers HQ: George Kittle ruled out, Dee Ford questionable

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Some context: Offensive coordinators often script the first 10, 15, 25 plays of a game. Both Shanahan and LaFleur do this.

And those predetermined plays work pretty well for Green Bay. The Packers are third in the NFL in first-quarter points (6.8), and seventh in third-quarter scoring (6.4).

What does that tell us? Well, when LaFleur has time to think; time to scheme — even if it’s only a few minutes at halftime — he’s pretty darn good at calling plays that move the ball down the field for Green Bay.

But the Packers are also 26th in second-quarter points and 28th in fourth-quarter scoring.

Wha does that say?

As Mike Tyson famously said — everyone has a plan until they get punched in the mouth. When LaFleur is proverbially punched, his offenses don’t respond.

We saw this play out in the Packers’ playoff game against the Seahawks last Sunday. Green Bay, which unlike its opponent, had a bye week, jumped out to an early 21-3 lead.

Then Russell Wilson started doing his magic act — what’s a defense to do? The Packers, after scoring a touchdown a little past the halfway mark of the third quarter, didn’t score again the rest of the contest, winning 28-23.

Rodgers — the future Hall of Fame and one of the greatest quarterbacks of a generation — was 3-for-8 in the fourth quarter against Seattle, though he did make two strong throws to ice the game.

For reference, the 49ers’ scoring ranks this year, by quarter, are fourth, eighth, second, and fifth. Shanahan and Garoppolo not only have a great game plan that’s well-executed to start a game, but they’ve also proven — and this is beyond debate — they can respond effectively to the dynamic changes of a game. Per Football Outsiders, the 49ers had the best offense in the NFL this year when trailing by more than a touchdown (though that was only 48 plays).

Pair the 49ers’ steady offensive output (second in the NFL in points this season) with a strong defense and you have an outstanding team.

But pair the Packers’ inconsistent offense with a defense that is aggressively average — and has glaring weaknesses that will be surely targeted by Shanahan — and you’re looking at a team that understandably needed all 60 minutes to hold off a gassed and injured Seahawks squad that barely had a positive point differential this season. Related Articles What we learned Friday at 49ers HQ: George Kittle ruled out, Dee Ford questionable

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It’s not like a breakout is looming, either. There’s no evidence that LaFleur has appreciably made Rodgers or the Packers’ offense better in his first year in charge.

Last year, Rodgers had a career-worst Total QBR (ESPN’s proprietary quarterback stat) of 58. That season cost Mike McCarthy his head coaching job and prompted the notoriously conservative Packers to go out and hire a young Shanahan disciple — a supposed quarterback whisperer — in LaFleur.

Yet this year, Rodgers posted a QBR of 50.4 and the Packers offensive DVOA went from seventh… to eighth, regressing mostly in the run game — which was the team’s strongest offensive characteristic most of the season.

It was improvements to the defense (though not enough of an improvement to make the unit anything more than 16th in weighted DVOA this season) and a weak division that brought about the Packers’ regular-season record. One could argue that they’re the least impressive 13-3 team in NFL history.

But hey, they beat the tired and hardly-impressive Seahawks at home, after a bye week.

Now, LaFleur is no chump, although Rodgers might treat him like one in the media, sometimes. The Packers’ coach was brought up by Shanahan and later Sean McVay, after all. (Matt’s brother, Mike, is the 49ers’ passing game coordinator.) But there’s a big difference between theory and practice.

And that difference can only be bridged through experience or preternatural talent.

LaFleur has neither, but this week in the biggest game of the year he’ll have to keep up with someone who has both.

The players on the field might determine games, but the coaches on the sideline have a say in this huge game, too, and the 49ers look to have a marked advantage there.