In a series that has been all about goaltending, from the matchup to the performance, Carter Hart has been the shining star.

Hart’s performance is only as good as the defensive work the Flyers put in to help him. He’s been getting that in nearly every game the Flyers have played since entering the bubble. He’s been getting so much help, the collectively as a team, the Flyers allowed more goals in Game 2 than they have in the entire playoffs, a 5-4 margin.

Tuesday seemed like just another day at the office for Hart, but it held some historic meaning for the 22-year-old goalie and the Flyers.

Here are the 5 takeaways from Game 4 of Flyers-Canadiens.

1. Another Shutout for Hart

Hart started this series by celebrating his 22nd birthday the day after recording his first win in a playoff series. He was on the hook for the toughest loss of his playoff career in Game 2, allowing four goals on 26 shots. In Game 3, he bounced back with a 1-0 shutout win, making 23 saves, on Carey Price’s 33rd birthday. How did he follow that up? Only with another shutout win, this time making 29 saves.

For Hart personally, that is now his second playoff shutout. It took him 33 regular-season games to get his first shutout in the NHL. In six playoff games, he now has two.

In addition to that, Hart is just the third goalie in Flyers history to post back-to-back shutouts in the playoffs. Michael Leighton did it against the Canadiens in Game 1 and 2 of their 2010 series. The other is none other than Bernie Parent, who had back-to-back shutouts in Games 2 and 3 of a quarterfinals series in 1975, the year the Flyers won their second Stanley Cup.

In NHL history, only three other goaltenders have recorded back-to-back shutouts before their 23rd birthday. Felix Potvin did it in April of 1994. Terry Sawchuk did it twice in a matter of 19 days in the 1951-52 season. The only goalie younger than Hart to have back-to-back playoff shutouts is Harry Lumley, who did it with the Detroit Red Wings in the 1944-45 season at 18 years and 161 days old.

It really shouldn’t come as a surprise anymore. Hart has so much poise and so much talent that these types of things are going to happen. He’s very much like his counterpart in this series in Price. Their games are so similar. Always square to the shooter. Always tracking the puck. Always in the right position. It’s rare for either to allow a bad goal. Hart has been so on top of his game, and just like when he broke through at the NHL level last season, he’s starting to take these playoffs by storm with his performances that just keep getting better and better.

2. Doing the Dirty Work

Alain Vigneault shuffled the lines around for Game 4 completely. Nothing looked familiar. Even that could not completely solve the Flyers scoring woes. Time and space are limited, and while the Flyers did a much better job finding both in Game 4 than any other game in this series and looked more like the team that played in Round Robin than in any other game in this series, they still struggled to generate shot.

One line that really impressed, though, was the line of Nate Thompson, Tyler Pitlick and Connor Bunnaman. It’s not a line that is designed to score or contribute in a huge way to the offense, so don’t look for that to be the reason they were so impressive. Thompson was a force on the forecheck and really put in the dirty work in this game. Thompson also blocked a Shea Weber shot in the third period that showed the dedication and willingness to sacrifice the body for the team’s success.

Bunnaman was a surprise addition to the lineup for Nicolas Aube-Kubel, who may have been feeling the effects of blocked shots from Game 3, and he certainly looked the part. Bunnaman’s style really complements the style that Montreal plays. Montreal wants to out-work teams and drive play with the forecheck. Bunnaman gave it right back to the Canadiens in this game, especially in board battles and won several.

In the playoffs, this is the style of hockey that wins. The Flyers have done what they had to do to get the lead in this series and then gone to work to shut it down. Montreal has struggled to get extended offensive zone time or quality chances down the stretch as a result of this style. Another similar effort could be the formula to close out this series.

3. A Rare Leaky Goal

Entering this game, the Flyers had three goals in three games in the series. Goals are hard to come by against Carey Price. But the way to beat him is to get shot volume and traffic to the net. If you take a large number of shots, you always have the possibility that one gets through.

Phil Myers found a way to get one through.

The Flyers finished the game with 22 shots on goal, but Myers took one from the outside that hit the stick of defenseman Brett Kulak and took a bounce on Price. The shot appeared to be going wide, but Price tried to deflect it to the corner and instead knocked it the other direction into his own net.

That is the type of shots the Flyers need to funnel to the net. You can’t be afraid to shoot on Price because the more you do, the more likely you are to get a leaky goal. It won’t happen often, but the Flyers got some important separation in this game by getting a second goal just like that, because there wasn’t much there outside of that.

4. Getting a Fast Start

In Game 4, the Flyers got off to a similar start in Game 3. It took them nearly the exact same amount of time to strike for the first goal of the game. In Tuesday’s Game 4, it took about 75 seconds longer than in Game 3, but that first goal of the game has set the tone for the Flyers.

Michael Raffl’s goal as part of the new-look line with Sean Couturier and Jake Voracek got the Flyers on the board. Just like in Game 3, the Flyers made a first-period goal hold up. That said, the approach the Flyers have taken at the start of games has been much better.

In Game 2, the Flyers were already in a 2-0 hole before they could even get a shot on goal and had their worst start of any game they have played in the playoffs. The last two games, the Flyers have been harder on the puck and generating more at the start. Even as the Canadiens try to apply pressure later in the game, the Flyers have come out with the better starts in both games and gotten the payoff.

Another start like that in Game 5 will be key, especially if the Flyers need to lean on their goaltender again.

5. Chance to Close It Out

Game 4 of a playoff series, especially in a 2-1 series, is pivotal. Win, and you take command of the series. Lose, and you are looking at a Game 5 that can be a turning point.

The Flyers win in Game 4 is critical because it puts them further in the driver’s seat in the series. Now, they have a chance to close out a series. They have a chance to put an end to the Canadiens hopes. They force the Canadiens to put everything on the line to keep their season alive. And that means that Montreal has to play a more reckless game. It means they have to lean on Price even more than before.

But that also means they will be coming harder than ever. They will do what they can to replicate the Game 2 effort and claw their way back into the series. They will try to be the harder working team and win more of the battles. The Flyers simply need to out-will them one more time.

The back-to-back situation in these playoffs has certainly been unique. The Flyers answered a lot of the questions that would be had in Game 4.

In net, the answer is clear. You go with Carter Hart. You go with the hot goalie. The approach also becomes much different when you are not the team playing for your life one day after playing another pivotal game. The Flyers can’t be completely care-free, but also don’t have to shoulder the pressure, which can be a benefit.

Add in that a lot of the Canadiens playoff hopes now rest on Price, who has an 0-2-2 record with a 3.76 GAA and .864 save percentage in the back-end of back-to-back games this season. Montreal was also 9-12-5 in games played in back-to-back situations, while the Flyers were 13-9-4. The Flyers get their chance to close it out on Wednesday night.

Kevin Durso is Flyers insider for 97.3 ESPN and Flyers editor for SportsTalkPhilly.com. Follow him on Twitter @Kevin_Durso.