Auston Matthews was named the NHL’s rookie of the year last season. (Jeffrey T. Barnes/Associated Press)

Just six months ago, when there was still unbridled hope in Washington, the Capitals got a close look at how fast the NHL is changing.

The Toronto Maple Leafs, an upstart team led by then-19-year-old Auston Matthews, leaped ahead of the top-seeded Capitals with a two-games-to-one lead in the Stanley Cup playoffs. Most of his teammates had never been to the postseason, and some of the other top contributors, such as William Nylander and Mitch Marner, also were younger than 21. They buzzed around the rink, turning the games into track meets on ice, bad bounces into scoring opportunities.

In the end, the Leafs lost in six games despite pushing the Capitals to overtime in five of the contests. But it likely was only a tease of how much Matthews and the league’s other young stars will influence the NHL moving forward.

“They have an unbelievable skill level coming in that’s really unparalleled in the last 100 years probably of the game,” Capitals Coach Barry Trotz said of the NHL’s newest crop of young players. “You always say, ‘Who’s the best player that ever played?’ The best player that ever played hasn’t been born yet. There’s someone better. We’re sort of seeing the next better. It’s in the areas of speed and skill, the nutrition, the training. It’s just evolving.”

Connor McDavid, who won’t turn 21 until January, edged Sidney Crosby for the league’s MVP last season. (Gene J. Puskar/Associated Press)

Since 2009, championship success has been concentrated among a few teams: the Boston Bruins won the Stanley Cup in 2011, the Los Angeles Kings won it in 2012 and 2014, the Chicago Blackhawks won it in 2010, 2013 and 2015 and the Pittsburgh Penguins did so in 2009, 2016 and 2017. That’s only four different champions across nine seasons, but now seems to be the time for other teams to ascend.

The speed and skill of the NHL’s young stars — a group headlined by the Edmonton Oilers’ Connor McDavid and Matthews but includes many more — not only is changing the league’s style of play. It is also squeezing out slower skaters and, as another season begins, could have a major bearing on where the power shifts next.

“If you ask 25 experts who they think are going to compete in the playoffs and ultimately win the Cup, you are probably going to get 25 different answers,” said Doug MacLean, a former NHL coach and general manager who is now a Sportsnet analyst. “That’s just how the league is right now — completely wide open. But I do think that if you don’t have one of these really good young players, you’re behind.”

MacLean sifts the young stars into two categories: franchise players and impact players.

The franchise players, according to MacLean, are McDavid, Matthews and Jack Eichel, who signed an eight-year, $80 million deal with the Buffalo Sabres on Tuesday. They are generational talents who are ripping through the starts of their respective careers. McDavid finished with an NHL-high 100 points and led the league with 70 assists last season. Matthews was a rookie last season and notched 40 goals (a league-high 32 at even strength) and 29 assists. Eichel has 113 points across his first two seasons, 56 as a rookie and 57 last year.

The impact players, according to MacLean, include Winnipeg Jets 19-year-old winger Patrik Laine, Colorado Avalanche forward Nathan MacKinnon and Calgary Flames forward Johnny Gaudreau. The 24-year-old Gaudreau is a 5-foot-9 speedster and one of the skating embodiments of the NHL’s tactical changes, with speed now favored over size.

But the NHL’s youth movement doesn’t stop there. The league’s latest collective bargaining agreement forces teams to commit a large portion of their salary caps to top players, leaving a lot of holes to fill with a little bit of cash. Teams are inclined to fill those holes with young players on inexpensive entry-level contracts. And those young players, more often than not, come into the league as fast skaters with years of skill training.

Though still one of the NHL’s top goal scorers, Alex Ovechkin has plenty of young company among the league’s upper echelon of stars. (Alex Brandon/Associated Press)

“The game getting faster, it really is a shift from the ground up,” said Craig Button, the former general manager of the Flames and now an NHL Network analyst. “I don’t think the intended consequences of rule changes and CBA changes was to change the entire game and make it a speed game, but that’s pretty much what has happened.”

Said Capitals General Manager Brian MacLellan: “It’s not a blue-collar sport anymore. When I was growing up, parents were working in factories, and you were getting hand-me-down stuff. These kids have personal trainers, skill development coaches. And they’re going to tournaments on weekends. Are you kidding me? It’s shifted to that. It used to be all blue-collar kids. It’s different now.”

Isabelle Khurshudyan contributed to this report.