Every generation of New Englanders which has witnessed the century of Bruins’ hockey have their iconic, indelible moments.

For the Greatest Generation, it may have been Milt Schmidt, Bobby Bauer and Woody Dumart being hoisted on the shoulders of their teammates as well as those of the archrival Montreal Canadiens in their final game before going off to serve in World War II in 1943. Boomers, of course, have Bobby Orr sailing through the steamy Garden air on Mother’s Day 1970.

And for Gen Xers like Joe Sacco, son of Medford and now coach of the team he grew up loving, it was Reggie Lemelin pumping his fist in the Montreal Forum after the Bruins finally beat the Canadiens in the playoffs in 1988 for the first time in 45 years.

On Sunday, the B’s – with their ancient foe, the Habs – will commemorate the organization’s first game that was played on Dec. 1, 1924 at the old Boston (now Matthews) Arena against the Montreal Maroons with an extravaganza celebration that will begin at 2:45 p.m. prior to the 4:14 p.m. puck drop at the new Garden.

Sacco grew up as a fan but now, as someone who has worked as an assistant for a decade and now as head coach for the team, his level of appreciation has grown.

“You don’t realize being part of an Original Six team how important that is and how much of a privilege that is,” said Sacco. “It’s going to be a great (Sunday), it’s going to be a great day for the fans, it’s going to be a great day for our players. You have two teams that are rich in tradition. There’s obviously a rivalry that goes way back and I remember as a young kid watching those games, the intensity in those games was pretty special back then.”

Brad Marchand has gone from an impudent rookie who raised the Stanley Cup in his first full season to a first line player to now the captain of the team. His journey has given him a good perspective on the team and what it means.

“I really appreciate their commitment to winning,” said Marchand. “It’s such a special thing that I think a lot of players take for granted, being a part of an organization that consistently puts themselves in position to compete for a Cup. That is ultimately what every player in the league has tried to accomplish throughout their career and from their childhood and have always dreamed of doing. Obviously, you fall short a lot of times. But every year, they put a team together that is competitive and could get there. It’s not something that every organization can do. I have a ton of respect form the top down. It’s starts with the ownership and bleeds trough everybody else.

“Ultimately their commitment to excellence is so far and beyond what I thought it was and what I knew coming into this organization. And when you see guys coming in from other organizations – I obviously haven’t gone through that firsthand – but you see it very clearly and hear it from everybody else who comes in, how special it is. It’s something I’m very grateful for now having played my whole career here and gone through it, the ups and downs. I didn’t really appreciate it as much early on. You’re just trying to survive and stay here. Once you get embedded and see it everyday, you see what makes this organization special. It’s incredible to be a part of.”

The Bruins don’t have the best batting average when it comes to Cups. There are six of them in 100 years. There has been some years they’ve underachieved, to be sure. There were more years when they played the part a fist-throwing David going up against a more elegant Goliath, often played by Sunday’s guest, the Habs. You could also point out that ownership’s business model, shall we say, kept them from winning one in the late 1980s, early ‘90s.

Outside events also helped to keep the Cup count down. The B’s were on the cusp of a dynasty after winning in 1939 and ‘41 but then came WWII. And one would think that there would have been at least one or two more Cups in the ‘70s if not for the advent of the WHA and another round of expansion.

Perhaps it’s the near-misses that make it so special when they do actually win it, like they did in 2011. This city has seen a lot of championship parades and celebrations in the 21st century, and the B’s Duck Boat drive in ‘11 remains one of the biggest we’ve seen here.

“It goes both ways. The fans are very passionate here with every sports team,” said Marchand. “They let you know when things are not where they expect it to be and they’re very hard on teams. But they’re very, very passionate. They support us all the way through. From being around the city and meeting everyone and seeing the excitement around the teams – not just our team but all the teams – it really is special and you really grow to love being part of the city and they embrace you like their own. So many guys make their homes here even after their careers and it really is a special place. The fans make it worthwhile. They give us the opportunity to play the game we love. It’s not like that everywhere. You go to these other cities. You go to the rinks and they don’t have the same passion that our fans do. It’s such a big part of why the team cares about putting competitive team on the ice every night and why we care to show up. They deserve it, they expect it and they’re behind us all the way.”

Loose pucks

There will indeed be a game to be played on Sunday, and you can expect some changes on the power play. In Saturday’s practice, David Pastrnak and Marchand were split up on two separate units. On Pastrnak’s unit were Charlie McAvoy, Morgan Geekie, Justin Brazeau and Pavel Zacha, while Marchand had Mason Lohrei, Charlie Coyle, Elias Lindholm and Trent Frederic.

Sacco wouldn’t commit to those being the units in the game.

“Obviously we’re having struggles with it right now and we wanted to cover all our bases and see players in different spots, see how it looked in practice,” said Sacco. … Another possible change could Jordan Oesterle going in for Parker Wotherspoon, though Sacco would only say that switch is a possibility.