Why are the Bruins so good? Duh, it’s because they’re from Boston and they all “get it” and nobody else wants to win as badly as they do.
Nope, it’s because they have a really good roster and a really good coach. The man responsible for that was rewarded on Thursday, as the B’s announced a four-year extension for general manager Peter Chiarelli. Since coming to the Bruins in 2006, Chiarelli has revamped the roster and taken the Bruins from cellar-dwellers to annual Stanley Cup  contenders and 2011 champs.
Though he often flies under the radar, Chiarelli has established himself as one of the best (if not the best) general managers in Boston in recent memory. He hasn’t been perfect, but he also hasn’t been afraid to do the unpopular thing. He’s made big moves (trading Phil Kessel  and later Tyler Seguin ) and he’s made smaller splashes where fans were calling for bigger ones (Chris Kelly , Rich Peverley ).
It’s easy to forget how these Bruins rosters came about over the years, so here’s a look at Chiarelli’s best and worst moves as B’s general manager.
(Definitely not) signing Zdeno Chara 
Chiarelli, who was working as the assistant general manager of the Senators, was hired by the Bruins on May 26, 2006, though he couldn’t begin working for the Bruins until July 15. Senators free agent defenseman Zdeno Chara , who highly respected Chiarelli, turned down a nice offer from the Kings and signed with the Bruins on July 1. So too did Marc Savard , which makes for a rare case in which a team was able to build itself into a contender via free agency in a salary cap league (Drew Brees  with the Saints also comes to mind).
Technically, it was interim general manager Jeff Gorton who made those signings — technically — but in getting Chiarelli, the Bruins were able to get Chara, and he has been the biggest piece of this whole thing.
(It should be noted that the Bruins made some important moves under Gorton. Chiarelli was actually sitting at the Senators’ table when the Bruins “reached” for Milan Lucic  with the 50th overall pick, took Brad Marchand  71st overall and traded for some kid named Tuukka Rask .)
The Bruins moved two-thirds of their return from the Joe Thornton  deal (they’d later trade Marco Sturm  for, in Chiarelli’s words, “nothing”) so it had to hurt some B’s fans to not see them get huge names for what they’d gotten for a Hart winner, but Ference ended up being a major part of both Cup runs for the Bruins. He was the unsung hero of the 2011 championship team and played a big role in neutralizing the Penguins  when the B’s allowed just two goals to them in the Eastern Conference finals last season. Factor in what he did for team chemistry and his contributions to the community, and Ference was worth both the trade and the three-year, $6.75 million extension the B’s gave him.
Byron Bitz, Craig Weller and Tampa Bay’s 2010 second-round pick for Dennis Seidenberg  and Matt Bartkowski
We’ll see what happens with second-round pick Alex Petrovic in Florida, but Bitz has played 17 NHL  games since the 2010 trade, while Weller played last season in Germany. Meanwhile, the Bruins got a top-pairing defenseman in Seidenberg and a very good young defenseman in Bartkowski, who scored in Game 7 against the Maple Leafs  and should stick in the NHL  this season.
Giving Dennis Seidenberg  a four-year, $13 million deal
This looks like a steal now, because it is, but Chiarelli was projecting that a guy who had been playing on one-year deals (he didn’t even have a contract the previous season until training camp) would become one of the best defensemen in the game. If Seidenberg had hit free agency a year later (after the Bruins won the Cup), he could have commanded major bucks and gotten them in a summer in which Christian Ehrhoff got 10 years and $40 million.
2011 second-round pick for Chris Kelly 
At the time that it happened, people scoffed at the move. It was viewed as “typical Chiarelli” by nay-sayers: The Bruins needed a replacement for the outrageously skilled Savard, so they went out and got a good penalty killer who had never scored more than 15 goals in a season. Any doubt went away once Scott Gomez messed up Kelly’s face and he started making magic on that third line with Rich Peverley  and Michael Ryder . Kelly scored 20 goals a season later and cashed in with a four-year, $12 million deal. The jury’s still out on that, but just remember that people also questioned Ference’s contract once upon a time.
Horton was a former 30-goal-scorer who the Bruins were convinced could become a 40-goal scorer if he were skating with Savard. That didn’t happen because Savard played a grand total of 25 games for the B’s in Horton’s first season with the B’s, which was Savard’s last. Horton did become a postseason hero for the Bruins, however, scoring the game-winning goal in double overtime against the Canadiens in Game 5 and then winning the series in overtime of Game 7 back in 2011. His biggest goal as a Bruin came two rounds later, when he scored the only goal in Boston’s 1-0 Game 7 victory over the Lightning to send the B’s to the Stanley Cup  final, something he did after separating his shoulder.
Horton also had a very good postseason for the B’s this past season despite playing with another separated shoulder suffered late in the season in a fight against Jarome Iginla. In 43 playoff games for the Bruins, he had 15 goals and 21 assists for 36 points.
Campbell, meanwhile, has thrived in his fourth-line role for the B’s. His 13 goals in 2010-11 tied a career high.
Martins Karsums and Matt Lashoff for Mark Recchi  and a second-round pick
He may not have been the 50-goal-scorer he was in the early 90s by the time he got here, but Recchi brought the B’s necessary experience and leadership and helped Patrice Bergeron  become the leader he is today. The Bruins traded the second-round pick acquired in this deal as part of the Seidenberg/Bartkowski trade.
Matt Hendricks for Johnny Boychuk 
Good defensemen are hard to come by, and the Bruins got one for the cost of Hendricks and a little bit of patience. Hendricks has established himself as a fine bottom-six player in the NHL , but Boychuk has become a legitimate top-four defenseman.
Hiring Claude Julien 
Maybe Chiarelli’s best get aside from Chara. Julien was fired mid-season by the Devils prior to the Bruins hiring him, but Chiarelli wasn’t afraid to can Dave Lewis after a season and bring in the Marty Schottenheimer  of hockey coaches, in that he could always get you a good record, but just hadn’t won it all. Julien changed that reputation in 2011.
Drafting Zach Hamill eighth overall in 2007
Hamill was the first pick Chiarelli made for the Bruins, and boy, was it the worst. Hamill, a mega-bust who played just 20 goal-less games for the Bruins before being traded last summer, was taken ahead of the likes of Logan Couture (ninth), Kevin Shattenkirk (14th) and Max Pacioretty  (22nd), among others.
The Chris Bourque experiment
Maybe the Bruins got cocky after having a successful regular season with Benoit Pouliot skating on the third line with Kelly and Peverley and figured they could plug anyone in there. They traded Hamill for Bourque and played Bourque in 18 games, making for a very unproductive third line that started to look OK once Jordan Caron joined it, but then Kelly got hurt.
Kris Versteeg for Brandon Bochenski
The Bruins got 11 goals out of Bochenski the season of the trade in 2006-07, but he was nothing more than a spare part the next season who ended up being dealt for Shane Hnidy. Versteeg has had three 20-goal seasons in the NHL , including 22 in 2008-09, when Bochenski was long gone from Boston and spending all but seven games of the season in the AHL for the Lightning.
Joe Colborne, 2011 first-round pick and 2012 second-round pick for Tomas Kaberle 
This was a bad trade only because Kaberle was bad (to put it nicely). Colborne hasn’t amounted to anything special, while the first-round pick was used by the Leafs to move up and grab Tyler Biggs 22nd overall. This trade didn’t work out for the Bruins, but it isn’t one they should necessarily regret.
The Phil Kessel  trade
There was a time when Bruins fans laughed maniacally at how much Chiarelli had fleeced Brian Burke in that 2009 trade that sent Kessel to Toronto for three draft picks. The picks became Tyler Seguin , Dougie Hamilton and Jared Knight, and here’s what we know: Almost four years later, it’s clear that the Leafs have the best player in the trade.
That by no means makes it a bad deal for the Bruins — Kessel didn’t want to be here and Hamilton’s going to be great, while they got a tremendous return on Seguin in Loui Eriksson (it’s too early to grade that trade on here, but it was ballsy and certainly looks to be a home run) — but to say the Bruins made out any better in this deal than the Leafs did would be arrogant. Both teams have to be happy with how the deal turned out.
Wheeler has become the top-six player the Bruins wanted him to be, while Stuart is solid and a great leader. At the end of the day, however, the Bruins don’t win the Cup without Peverley in 2011. Boris Valabik is a person who is tall, and that’s all you need to know about him.
2013 conditional second-round pick (became a first-round pick), Lane MacDermid and Cody Payne for Jaromir Jagr
Jagr didn’t score in the postseason, put he still wore other teams down while logging top-six minutes for the Bruins. With Seguin’s postseason no-show there’s no way they would have made it as far as they did if Seguin was still on that second line rather than Jagr.
Scott McLaughlin contributed to this report