The United States and Canada have met in the gold-medal games of all 15 tournaments to date.
All but one of Canada's recent defeats in the final were one-goal losses, but the fact is the U.S. has become harder to finish off in the world championship finale.
The two countries open the 2015 world championship Saturday in Malmo, Sweden, against each other in a Pool A game. Finland and Russia round out their group, with host Sweden, Switzerland, Germany and Japan featured in Pool B.
Caroline Ouellette scored Canada's overtime winner in Burlington, Vt., in 2012 for her team's only world title in the last five championships. The Montreal forward said then: "We can't say anymore we are better than them."
In their most recent meeting, Canada edged the U.S. 5-4 in a shootout to win the Four Nations Cup in November.
"Maybe early on when women's hockey made its debut at the world championship, Canada probably had the edge over the United States," Ouellette said Friday in Malmo. "(Canada) had more depth, maybe better preparation and they were able to dominate those games.
"(Now) we know not much separates us from the U.S."
Canadian head coach Doug Derraugh of Arnprior, Ont., did not reveal his starting goalie Friday. Genevieve Lacasse of Kingston, Ont., made 33 saves and another three in the shootout to earn the Four Nations final win.
With games between the North American rivals turning on small details and moments, there isn't a glaring reason for Canada to become less dominant at the world championships. There could be a contributing factor, however.
Canada may be winners of the last four Olympic gold medals — including last year's overtime thriller against the Americans — but the Winter Olympics are a different animal than the world championship.
All players from the world's top female hockey countries have adopted the Canadian model and now suspend school and work for an entire winter. They train full-time with their respective national teams for the Games.
Women's world championships aren't held in the same year as an Olympic Games.
In the years in between Olympics, they go back to playing for their college or university, or return to work and their club teams.
The U.S. roster at a world championship typically has more college players on it, with 13 this year compared to Canada's eight.
The American squad that beat Canada 3-2 for gold two years ago in Ottawa had 11 compared to Canada's six.
A college or university team mirrors Olympic preparation in that the players are on the ice almost every day, can play up to 40 games in a season and dryland train with their teammates.
The Canadian Women's Hockey League is important for female players who have already graduated or who aren't in school. Without it, 15 players on Canada's current roster and five on the American team wouldn't have a place to play.
But CWHL players practise twice a week and play no more than 27 games in a season.
A roster heavy in NCAA Division 1 players can have another impact. Their Frozen Four final is often less than a week out from opening day at the world championship, while the CWHL's Clarkson Cup championship wraps up two to three weeks before the tournament.
For example, 10 U.S players participated in last weekend's Frozen Four in Minneapolis, including four in Sunday's championship game.
Immediately joining the U.S. team extends their season's peak. They ride adrenaline and a high level of play right into the world championship.
"Anybody that's coming from the college game, where you're playing every day, practising with your team, you're conditioned at a high level to jump into this type of situation playing against great international players from all over," U.S. goaltender Jessie Vetter said.
"I think it's an advantage for anyone who comes from college. We look to our college kids quite a bit throughout the worlds."
Canada had three players in the Frozen Four with Harvard goaltender Emerance Mashmeyer taking the loss to Minnesota in the final. For those who played in the Clarkson Cup, won by the Boston Blades, their season ended March 8.
Hockey Canada's director of female hockey is aware that if the CWHL continues to be the primary supplier of the women's national team, more attention must be paid to those players' daily training environments.
"This year, we've spent a lot of time with the players and following them and getting them into good training situations off-ice," Melody Davidson said. "The next step is to tackle what actually happens on ice because they only practise twice a week.
"We really have to look at the on-ice piece now and how we can best support the CWHL and how we can best support our own individual players."