Coming into the season, the Boston Bruins appeared to meet all the qualifications of a team whose window to win a Stanley Cup was closed.
The B's looked as if they would be heavily reliant on stars who were either in the latter years of their prime or past it; they'd made questionable trades of young stars and had a goalie coming off back-to-back mediocre seasons.
Instead, Boston is not only competitive, but they're also making a case as the NHL's second-most-dangerous team behind the Tampa Bay Lightning.
Boston ranks No. 3 in team Corsi for percentage, second in even-strength goals for percentage, ninth in power play percentage and eighth on the penalty kill.
Simply put: The Bruins' Stanley Cup window is wide-open.
Elite players are still elite
Years down the road, we might find that age curves shifted in the 2010s. With an emphasis on health, fewer fights and head hits as well as more work being done to study factors like dehydration and workload, it's possible that hockey players' primes will last into their 30s instead of ending in the late 20s, as current age curve models suggest.
The Bruins could be evidence of this effect. Forwards Patrice Bergeron and Brad Marchand, ages 32 and 29, respectively, are having among their best seasons in 2017-18.
With a hat trick on Thursday night, Bergeron has 19 goals and 19 assists in 39 games. His 57.9 percent Corsi for percentage ranks third in the NHL among forwards, with only Chicago's Brandon Saad and Columbus' Artemi Panarin ahead of him. When Bergeron has been on the ice this season, the B's have taken 161 more shots than their opponents and outscored them 30-9.
Bergeron's longtime linemate Marchand is leading the team with 46 points, placing him just inside the top 20 in the league despite missing a handful of games. He ranks fifth in even-strength scoring rate, with 3.39 points per 60 minutes.
These numbers are all on par or better than when the Bruins won the Stanley Cup in 2010-11. Bergeron produced 57 points in 2010-11 with a 54.2 Corsi for percentage, while Marchand had 41 points in 77 games.
Zdeno Chara, who will turn 41 in March, is still playing more than 23 minutes per game, down about just two minutes from 2010-11. And while his shot differential numbers have slipped from seasons past, the 6-foot-9 blueliner still isn't letting anyone get in front of the net. With Chara on the ice, the Bruins have produced 158 high-danger chances to their opponents' 129, according to Natural Stat Trick.
Veteran stars David Backes (33) and David Krejci (31) have missed time this season, but when in the lineup they are each making significant contributions. The former Blues captain has 18 points in 27 games and wins 52.9 percent of his faceoffs, while Krejci has 23 points in 26 games.
The combination of all of Boston's veterans clicking at once has helped push the Bruins to an 8-0-2 record in their past 10 games and moved them into the top five in even-strength goals for and fewest goals allowed.
The youth movement
Bergeron, Marchand, Chara, Backes and Krejci aren't driving the Bruins' success alone. For a team that has rarely drafted early in the first round during the past decade, Boston has a remarkable number of key players under the age of 23 playing key roles. In fact, of the Bruins' top six scorers, four are 23 and under.
That group starts with David Pastrnak, 21-year-old right winger flanking Bergeron and Marchand on Boston's deadly top line. Last season, the Czech forward broke out to the tune of 70 points in 75 games. He's been even better this season, with 41 points in 44 games.
The Bruins selected Pastrnak with the 25th overall pick in the 2014 draft. The knock on him was size and strength, but his high-end skill allowed an instant jump from playing in Sweden. Of all the players drafted in 2014, only Leon Draisaitl has more points than Pastrnak.
Another first-rounder Jake DeBrusk, 21, has made an immediate impact in his rookie campaign, scoring 20 even-strength points in 40 games while largely playing alongside Krejci.
The pleasant surprise of the group is Danton Heinen, a fourth-round pick in 2014 who scored more than a point per game at the University of Denver and had a solid 2016-17 in the minors. He's made the jump smoothly, adding 19 even-strength points in 40 games, playing the majority of his minutes with Riley Nash and Backes.
The biggest difference-maker in the bunch is 20-year-old rookie defenseman Charlie McAvoy. He joined the Bruins in the postseason last spring and immediately took on a top-four role. He's built on that experience this season, averaging 22:47 per game in ice time. The former Boston University blueliner has 24 points, 15 of which have come in even-strength assists. McAvoy has become a consistent puck-moving partner for Chara.
Boston's collection of under-23s isn't just bringing them value in the form of impressive production; those players are also allowing the B's to survive huge veteran contracts.
Take the Chicago Blackhawks for example. With mega deals handed out to Patrick Kane and Jonathan Toews, Chicago struggles to find cheap depth that will support its stars. For the Bruins, the total cap hit of DeBrusk, Heinen and McAvoy is just $2.65 million. Boston saved in per-season spending by doing a six-year deal with Pastrnak, whose cap hit is a reasonable $6.66 million.
The youngsters also give the Bruins the type of depth required to go deep in the postseason. Even if players like DeBrusk, Heinen and McAvoy are inexperienced, Boston has them playing alongside veterans who have made deep postseason runs.
The goalie
No matter how deep we dig into the numbers or what technology arises, we might never fully understand a team's impact on goalie performance. But in Boston's case, it's pretty easy to draw a connection between a stronger, deeper team and a better defense corps this season helping out Tuukka Rask.
At his absolute peak, Rask's even-strength save percentage was an otherworldly .943. That mark slipped for three straight seasons, all the way down to .919 in 2016-17. Normally a goalie's even-strength numbers are more predictable from season to season than his overall save percentage, so a three-season slide would be cause for concern. But he's rebounded to a .928 save percentage in 2017-18, which may have something to do with the Bruins allowing the fewest high-danger chances in the NHL, per Natural Stat Trick.
Debates will rage for eternity as to whether teams should pay big money for top-notch goalies, but one thing is clear: Good goaltending is a requirement to win the Stanley Cup. Rask has been excellent in his postseason career, posting a .928 save percentage and giving the B's quality starts in 62.3 percent of his starts.
The next step
The Bruins don't have to make a move at the trade deadline to enter the playoffs as a legitimate contender. They already have an elite top line, two other solid scoring lines, two solid defense pairs and strong goaltending -- all the ingredients necessary.
Still, there could be an opportunity to add another cheap veteran role player down the stretch, like Carolina's Derek Ryan, Edmonton's Mark Letestu or the Islanders' Jason Chimera.
With this group, the balance is excellent between experience and youth, so the Bruins should be wary of throwing things off. However, one thing to keep in mind: Boston's window is clearly open now, but once players get into their late prime, it's hard to predict when they will fall off. So it should be win-now mode all the way in Boston.