The Boston Bruins are going back to the Stanley Cup Final because they have a system of play in which they believe implicitly. That faith is the bedrock to all that they do.

"It just shows what a team can do," defenseman Dennis Seidenberg said after the fourth-seeded Bruins completed an improbable sweep of the top-seeded Pittsburgh Penguins in the Eastern Conference Final. "They have a lot of firepower, a lot of quality scorers over there. But if you play as a team, defend as one, I think you can do what we did in this series and that was just playing good defense, a lot of layers and play hard."

A similar formula already delivered the Bruins ultimate glory in the form of the Stanley Cup they won two seasons ago. In an unforgettable comeback victory against the Vancouver Canucks, Boston won four of the final five games.

Now they are back on hockey's biggest stage -- against the Chicago Blackhawks, who eliminated the defending champion Los Angeles Kings on Saturday night to win the Western Conference Final -- following a script that again features a dominating performance from its goaltender, a suffocating team defense anchored by tower of power Zdeno Chara, and a balanced and opportunistic offensive attack.

After surviving a first-round scare against the Toronto Maple Leafs, which featured one of the most improbable third-period comebacks in NHL history in Game 7, the Bruins have embraced their identity and sailed through the Stanley Cup Playoffs, losing once in their past nine games.

Amazingly, they did not lose at all in the conference final against a high-octane Penguins club that entered the series as the highest-scoring team in the postseason. Pittsburgh left with two goals in four games -- neither by any of their superstars.

"It was a great effort by everybody," center David Krejci said. "We take pride in our defensive game. And to sweep a team like that, the highest scoring team in the League this year, it's a pretty cool feeling. But in the playoffs you have to stay in the moment. We're going to enjoy the win tonight, but we know we're not done yet. "

Here are five reasons the Bruins aren't done yet and will play for a second Stanley Cup in three seasons:

1. Tuukka time

Boston goalie Tuukka Rask had a series for the ages. He stopped 134 of the 136 shots he faced from the most talented offense in the game today. His save percentage of .985 across almost 280 minutes of hockey is practically impossible to comprehend, as is the fact he allowed one goal to a desperate Penguins team in the final six periods of the series.

His lunging save on Jarome Iginla at the final buzzer in Game 4 pretty much sums up Rask's ability to make the clutch save in crunch time and leave world-class shooters looking for answers.

"He's been playing phenomenal and he gives us a chance to win every night, even if we're not playing at our best," Boston defenseman Johnny Boychuk said. "He's Tuukka."

2. Decision day

The Bruins won -- and in convincing fashion, at that -- because of the decisions coach Claude Julien made throughout the series.

The biggest one was the manner in which he deployed his defense. In the end, Julien decided to keep his shutdown pair of Zdeno Chara and Dennis Seidenberg together. Then he decided to pit that unit almost exclusively against the Evgeni Malkin line, placing trust in the fact that the Andrew Ference pairing could contain Sidney Crosby's line.

Julien got the forward matchups he wanted throughout the series as well. Even when the Bruins played the first two games on the road, Julien repeatedly found a way to exploit the Penguins with his decisions.

Nearly immune to the constant criticism that is part and parcel of his job, Julien showed an implacable faith in his players and his game plan. That confidence clearly was transferred to his players.

"I've been here for six years. I think I've been fired five times," Julien said. "You know, those kinds of things really are not important to me. What's important is the results."

3. Prep time

By dispatching the New York Rangers in five games in the second round, the Boston Bruins earned a full week off before starting the Eastern Conference Final.

Tuukka Rask

Goalie - BOS

RECORD: 12-4
GAA: 1.75 | SVP: 0.943

Boston was decimated on the blue line during the first two rounds when Seidenberg and Ference went down with injuries. Seidenberg was the first one back, and Ference was able to heal enough during the layoff to be declared fit for Game 1.

His importance to the Bruins can't be overstated. A wily vet of the playoff wars with enough speed and tenacity to draw and complete his assignment as a shutdown guy against an elite offensive line, Ference gave Julien the opportunity to rotate his defensemen to maximum effectiveness.

"To be able to win the series against New York in five [and] get that week off really gave us our second wind," Julien said. "That was important. It gave us a chance to prepare for the Penguins, and it also gave our guys an opportunity to get some rest. We knew we had to be at our best to beat this team. That's exactly what happened."

4. Killer instinct

Pittsburgh went 0-for 15 on the power play in this series after scoring 13 power-play goals in the first 11 games of the postseason. In a taut Game 3 decided in double overtime, Pittsburgh went 0-for-6 with the extra man.

The Bruins' penalty kill was a sight to behold, taking away every tendency Pittsburgh used to its advantage in earlier series against the New York Islanders and Ottawa Senators. Pittsburgh could not get the puck into the zone regularly, could not gain possession when it was able to dump it in, and had its shooting lanes disappear as fast as they opened.

Then, of course, there was Rask.

"Always said your best penalty killer has to be your goalie," said forward Chris Kelly, one of Boston's primary penalty killers. "Tuukka was unbelievable for us. He made those big saves when there were breakdowns. I thought we did a good job taking their time and space away and staying compact. We didn't let them seam us too often and we didn't give them any freebies."

5. Tower of power

As good as Rask was, there is a compelling argument Zdeno Chara was the MVP of the series.

His game-clinching arm save in the hectic final seconds of Game 4 will be on the Bruins sizzle reel for the rest of the playoffs, but his impact runs so much deeper.

In the four games against Pittsburgh, Chara played 119 minutes, often pitted against Malkin's line at even strength or for long turns on each of the 15 penalty kills. He used his reach and ability to get body position on attacking forwards -- and he did so without ever getting rattled.

"We were committed to do the little things, and really buy into our structure, what we want to do defensively," Chara said. "Let's not kid ourselves; they have the best offense in the world and they are an unbelievable team. They probably deserved better, but we were just playing under our game plan and exposing what we do well and trying to limit what they're trying to do."