The Calgary Flames enter Wednesday night's game (9:30 p.m. ET, ESPN+) against the Buffalo Sabres as the top team in the Western Conference, stashing 30 wins in 47 games. Only the mighty Tampa Bay Lightning have a better record league-wide.

Sure, it helps when Johnny Gaudreau and Sean Monahan have 27 and 25 goals, respectively. And yes, it's been nice to have Elias Lindholm and Matthew Tkachuk break out. Even the defense has been stout. But the real reason the Flames haven't fallen behind the Vegas Golden Knights or San Jose Sharks in the Pacific Division? David Rittich.

The NHL on ESPN+ Catch 300-plus NHL games streaming live or on replay this season on ESPN+. Click here for the upcoming schedule and to learn how to subscribe.

In 24 starts, the 26-year-old Czech netminder has 17 wins for Calgary. He boasts a .920 save percentage and a 2.46 goals-against average, and has been even better against conference foes.

It goes without saying that a team needs a competent goaltender to win (hey there, Philadelphia Flyers), but Rittich's real value comes from the fact that he wasn't supposed to be the guy this season. Entering the season, it was expected that he would back up Mike Smith -- after narrowly beating out Jon Gillies for the No. 2 gig -- and just see a start here and there behind the veteran.

Flames goalie coach Jordan Sigalet even told The Calgary Sun at the tail end of the preseason, "Ritter has to fight every day to keep his spot up here."

OK, that's all fine and well. But what happens when you've built a roster to contend and keep pace in the meat grinder that is the Western Conference, and all of a sudden your No. 1 goalie -- whom you rely on for 50-plus starts and steady play -- falters hard almost immediately out of the gate and never pulls out of the nose dive? The backup needs to step into the spotlight. "Big Game Dave" has done exactly that, and here's how.

We've seen this trend of an anointed starter failing quite a bit, and it has been a common theme with the Flames since Miikka Kiprusoff retired. The Flyers have dealt with their fair share of it, running seven different goalies out of the tunnel this season. The Carolina Hurricanes have struggled with underperforming starters (read: Scott Darling), Cory Schneider's rapid decline hit the New Jersey Devils hard, and the New York Islanders wasted their final season with John Tavares in part due to poor goaltending. Nine times out of 10, when a starting goalie turns in a bad season, the team collapses in on itself.

Without many options, the Flames turned to Rittich, who is only in his third season on North American ice and began the 2018-19 season with all of 16 NHL starts under his belt (with lackluster results). All Rittich did was post a .939 save percentage in October, helping buoy the club as Smith flopped to a .878 in the opening month (he has yet to reach .900 in any month and has generated an .889 on the season).

If Rittich doesn't answer the bell, it's anyone's guess where the Flames are right now. But we can confidently predict they wouldn't be holding off the Golden Knights and Sharks in their division. And they most certainly wouldn't be pacing the West. It's why having a sturdy No. 2 goalie is ever so important in today's NHL. Besides providing effectiveness when the starter needs a day off, as the league continues to see fewer and fewer true Martin Brodeur-esque workhorses, having a reliable secondary netminder gives teams options.

Of the top 10 goalies in even-strength save percentage with at least 15 games this season, five opened the campaign expected to ride pine more often than not: Rittich (.934), Jaroslav Halak (.933), Jack Campbell (.932), Anton Khudobin (.932) and Casey DeSmith (.928). Names like Curtis McElhinney, Linus Ullmark and Mikko Koskinen aren't far off that pace, either. What happens to the Bruins and Penguins if they don't have reliable options when Tuukka Rask and Matt Murray are slow to get in gear in October?

Halak and Khudobin were big offseason signings for the Bruins and Dallas Stars, respectively. Boston has handed Rask and Halak an equal 23 starts apiece, while Khudobin has handled about 40 percent of the starts for Big D. Workloads continue to level up. Toronto's Frederik Andersen is the only one of 14 goalies to start more than 30 contests with a save percentage sitting at .920 or better.

Look around the NHL and you'll see more and more clubs heavily valuing the No. 2 goalie roster spot, keeping the starter fresher while not sacrificing too much in the crease. But it also provides bailout options, like what we've seen in Calgary. If Rittich doesn't perform at or near this level, the Flames aren't where they are today.

Whether Rittich continues to stand tall in the net for Calgary is another question. We've seen lightning in a bottle before from other surprise performers standing in for struggling or injured starters. And the Flames would be wise to investigate all options in the goaltending market at the trade deadline. But regardless, he got them to this point. Without discounting the tremendous seasons of the young talent up front, the Flames owe their season to a goaltender who almost didn't make the team.