For all of the time we spend analyzing the Stanley Cup playoffs and why teams win or lose, it often times comes down to one very simple thing: Which team has the better goalie?

It can be the ultimate equalizer in a series (or, if you are the Montreal Canadiens, an entire season) and is the one position that consistently change the outcome of a game. And in a best-of-seven series, one game is often all it takes to decide which team moves on.

While the Pittsburgh Penguins try to figure out what to do with their situation in net after their Game 5 switch did not work, the Tampa Bay Lightning have had, by far, the best goalie through the first five games of the Eastern Conference finals series. It is probably the biggest reason they carry a 3-2 series lead into Game 6 on Tuesday night in Tampa Bay.

It's just not the goalie we expected to be making the difference for them when the series started.

As Ben Bishop, one of the finalists for the Vezina Trophy this year, remains sidelined with some sort of lower body injury, Andrei Vasilevskiy has been showing why the Lightning used a first-round pick on him in 2012, and why he has been such a highly touted prospect over the past couple of years.

Andrei Vasilevskiy is getting the job done for the Tampa Bay Lightning. Charles LeClaire, Charles LeClaire-USA TODAY Sports

It might seem odd to call him the difference in the series when you see he has given up at least three goals in every game he has started. But then you look at the workload he has had to face. It has not been easy. After replacing Bishop just 12 minutes into Game 1, a relief appearance where he stopped 25 out of 26 shots, he has had to face 41, 48, 38 and 34 shots in the four starts that have followed. The Penguins have not only outshot Tampa Bay by 65 shots on goal in the series through the first five games (196 to 131) they have also at times had the better of the chances.

While the Penguins' duo of Matt Murray and Marc-Andre Fleury has managed only an .885 save percentage on their opportunities, Vasilevskiy is rolling along at .924. This is not a matter of him getting easier looks or soft chances. He has faced breakaways, odd-man rushes and wide open looks. He was nearly flawless in relief of Bishop in Game 1, and was probably the biggest reason Game 2 made it overtime and his team even had a chance in that game. The same can probably said for Sunday's 4-3 overtime win where he made what might be his biggest save of the series to this point when he made this stop on Chris Kunitz.

(Vine via @TheGoalieGuild)

He has been making saves like that the entire series. The fact he has still given up 14 goals in the five games says more about the quantity -- and quality -- of shots and chances he has had to face than anything about his play.

At that point in the game the Lightning were still trailing 3-2.

If Kunitz scores there, the game is probably over, Pittsburgh wins, and the roles in the series are completely flipped heading into Game 6.

The Penguins are not getting that stop in this series. The Lightning are. Immediately after that save everything started to unravel at the other end of the ice. Ryan Callahan nearly tied the game with a quick shot off the rush that hit the goal post behind Fleury, and then less than a minute later tied the game on a wrap-around goal to send it to overtime.

From there, Tyler Johnson's backside did the rest.

In their two playoff matchups against the New York Rangers and Washington Capitals it was the Penguins that ended up getting the goaltending advantage. That doesn't mean Murray is better than Henrik Lundqvist or Braden Holtby from a big picture perspective, but he was better in those 11 games at that exact moment.

A lot of times in the playoffs that is all a team needs.

In this series, the tables have been turned on them and it is Tampa Bay's young goalie that is making the biggest impact.

Nobody really seems to know when Bishop will be able to return to the Lightning lineup, but given the way Vasilevskiy has played so far they really have no need to rush him back.