In trying to make a case for the Blues staging a stunning first-round upset to bring down the Colorado Avalanche, we spend a lot of time talking about the essential need to prevent the Avs from scoring.

The Blues must slow Colorado’s high-speed rail of an offense and derail it if possible. Must limit the succulent scoring chances and erase opportunities. Must repress the Avs top line. Must rely on goaltender Jordan Binnington to be a hero, straight from the Marvel Cinematic Universe.

Here’s what we don’t talk about enough: none of this defense-shield planning will mean a damn thing unless the Blues can score goals of their own against a Colorado team that dominates possession and most of the shots.

When the Avs ignite their offense, go on the attack and apply extreme pressure, their opponents have to stay in the protection mode. You can’t get your offense going forward when you’re under siege, going backward, and defending.

The Blues’ 4-1 loss in Game 1 was all we needed to see to reaffirm what we already knew, minus the cheerleading: the Blues are in a very tough spot in a matchup against a Colorado whirlwind.

When the teams competed Monday night at five-on-five, the Avs had 71.6 percent of the shots on goal, 71% of the scoring chances, and 70.5% of the high-danger salvos.

The Avalanche swarmed the fearless and unflinching Binnington, who kept his team closer than it should have been or deserved to be. This was a blow-out disguised as a two-goal victory for the Avs, who potted their fourth goal into an empty net.

Binnington stopped 46 of 49 shots overall including a 41 of 43 at even strength. “There’s never a doubt with Binner,” Blues captain Ryan O’Reilly said. “He’s our best player. He showed it tonight. We know it’s there. We were right in that game.”

Yes, the Blues were level at 1-1 going into the third period. This was a miracle on ice, performed by the supernatural Binnington.

Not that Binnington was under duress or anything … but after the Blues began the first period with a couple of incursions into the Colorado zone, the Avs had 50 of the final 70 shots on goal in this game.

Mercy.

And this is hardly a surprise; during the regular season the 39-13-4 Avalanche were the NHL’s most authoritative team at five-on-five. They controlled 59 percent of the overall shot attempts, 58% of shots on net, 60.4% of the scoring chances, and claimed just under 60% of the goals scored. The percentages led the league in each category.

It’s difficult to outscore the Avalanche when you don’t have the puck or the ability to thwart their supremacy. Binnington helped the Blues snatch three regular-season wins over this mighty nemesis — but the Avs have a Binnington of their own in Philipp Grubauer.

This:

In his final 21 regular-season games — including a 2-1 victory over the Blues at Enterprise Center — Grubauer was 18-2-1 with a .928 save percentage and four shutouts. And his .931 save rate at five-on-five ranked No. 5 among NHL goaltenders over that time.

In 14 regular-season home games since March 10, Grubauer was 13-0-1 with a spectacular .956 save percentage at five-on-five, and .939 overall. And his save percentage of .907 on high-danger shots was absurdly grand.

Including Monday’s win over St. Louis, Grubauer has yielded only 12 even-strength goals in his last 15 home games.

In his last three starts against the Blues (including Monday) Grubauer has allowed two goals, total.

That’s not all.

Keep in mind that the Avs’ possession control puts a cap on opponent shots on goal. If Colorado holds form, the Blues won’t give Grubauer nearly as much of a test as the Avs will throw at Binnington.

This season the Avs have allowed only 25.2 shots on goal per 60 minutes, lowest in the league. The average is even lower (23.9) at five-on-five.

Grubauer faced fewer shots per 60 minutes (25.1) than any No. 1 goaltender in the NHL. And the same applies to his average of 23.7 shots faced at five-on-five.

Grubauer was No. 1 in the NHL in goals allowed per 60 minutes overall (1.95) and No. 1 in goals allowed per 60 at five-on-five (1.87.)

In his last two games against St. Louis — the April 3 win at Enterprise Center, and the postseason opener on Monday — Grubauer has stopped 49 of 51 shots for a .960 save percentage.

It would help the Blues to have David Perron available to generate goals with his passing and scoring. Vladimir Tarasenko would boost his team’s offense by burying goals when set up for sweet-spot opportunities. He had two chances to do that Monday and came up empty.

It’s asking a lot of O’Reilly and linemates Brayden Schenn and Jaden Schwartz to carry the Blues with their scoring when they are consumed with the strenuous, burdensome task of shutting down the Nathan McKinnon, Gabriel Landeskog and Mikko Rantanen line.

Including Monday’s game, Colorado’s top-gun line has outscored opponents 66-21 at all strengths, 41-20 at even strength, and 37-16 at five-on-five.

The Blues beat Grubauer one time this season — the season-opener for both teams on Jan. 13 in Denver. They got four pucks past Grubauer on 32 shots, winning 4-1. The guy who scored two of the goals, Oskar Sundqvist, was lost for the season to a knee injury on March 19. Do the Blues have another Oscar in the house?

Down 0-1, do the Blues have any chance at all in this best-of-seven series?

Binnington is highly capable of stealing a game or two for the Blues. That’s been established. But that is no longer the most pertinent question. I want to know if the St. Louis shooters are capable of stealing games from Grubauer.

Thanks for reading …

–Bernie

Please check out Bernie’s sports-talk show on 590-AM The Fan, KFNS. It airs Monday through Thursday from 3-6 p.m. and Friday from 4-6 p.m. You can listen live online and download the Bernie Show podcast at 590thefan.com  … the 590 app works great and is available in your preferred app store.