CALGARY — A Canadian rival's assist fills a gap for Brendan Bottcher at the men's world curling championship.

The world championship stones in Calgary are not the rocks Bottcher and teammates threw to win a Canadian title last month in the same arena.

The World Curling Federation's stones employed at WinSport's Markin MacPhail Centre were last tossed at the 2019 men's world championship in Lethbridge, Alta., where Kevin Koe represented Canada.

Colton Flasch, Koe's second that year, has supplied Bottcher's foursome with a "rock book" that is a scouting report on each stone's movement.

"He gave us his book from the '19 worlds," Bottcher third Darren Moulding said. "That just shows us Canadian curlers, we've got each other's backs."

Bottcher, Moulding and front end Brad Thiessen and Karrick Martin from Edmonton came from behind to beat Scotland's Bruce Mouat 9-6 in Canada's opener Friday.

Down 5-2 at the fifth-end break, Canada scored two in the sixth, seventh and ninth ends to be up 8-6 coming home without last-rock advantage.

The Scots couldn't generate a deuce with hammer and gave up a steal of one. Mouat, a bronze medallist in 2018, is a contender for the title in Calgary.

"We were resilient that game," Bottcher said. "We battled hard. That was a big win for us in the course of the week.

"I'd be lying if I said there wasn't a little bit of butterflies. It's a pretty cool feeling. We've been wearing the (Canada) jerseys for a few days now. We're playing in a world championship. That's frigging cool."

The hosts also topped Japan's Matsumura Yuta 8-5 in an evening draw to move to 2-0, while Scotland responded with a 7-2 win over Denmark to even its record 1-1.

Koe defeated Bottcher in the 2019 Tim Hortons Brier final and took silver in Lethbridge behind champion Niklas Edin of Sweden.

Nine of 14 skips in this year's BK Tires and OK Tire World Men's Curling Championship also competed in Lethbridge.

They have stone intelligence the Canadians would lack if not for Flasch's generosity.

"We are all Team Canada and anything to help them," Flasch wrote in a message to The Canadian Press.

"I would think with no information they would be at a slight disadvantage and any extra information early in the week would only help them."

The WCF's stones feel lighter and not quite as lively in the house as the Brier rocks, said Moulding.

"They are different stones than we used in the Brier and running a little bit differently than we're used to seeing," Bottcher said.

The Russian Curling Federation team skipped by Sergey Glukhov won twice Friday. Glukhov's official team name is Russian Curling Federation because of World Anti-Doping Agency sanctions against his country.

Norway's Steffan Walstad and Italy's Joel Retornaz also went 2-0 on Day 1.

Reigning Olympic champion John Shuster of the United States and Switzerland's Peter de Cruz opened with wins Friday to sit 1-0, while Japan's Matsumura was alongside Scotland at 1-1.

The Swiss edged back-to-back world champion Edin 8-7 in an extra end.

Sweden and Germany's Sixten Totzek were 0-1, while Jaap Van Doorp of the Netherlands, Denmark's Mads Noergaard, South Korea's Jeong Yeong-seok and China's Zou Quiang started 0-2.

No spectators are allowed in the arena, which was also the case at the Canadian men's, women's and mixed doubles championship in Calgary preceding the men's world event.

Participants were subject to quarantine and testing before getting on the ice. They're confined to the arena and the hotel while competing to avoid the COVID-19 virus.

"We feel safe," Norwegian third Torger Nergaard said. "They had a few test events before the guys from Norway came, so that's good."

The top two teams in the round-robin standings earn byes to the semifinals April 10.

Third through sixth compete in qualification games with third versus sixth and fourth versus fifth.

Qualification winners advance to the semifinals. The gold and bronze-medal games are April 11.

Head-to-head results, and then pre-game draw-the-button distances, solve ties.

The top six teams qualify their countries to compete in men's curling in the 2022 Winter Olympics in Beijing.

This report by The Canadian Press was first published April 2, 2021.