* Russia, Canada, United States debut in men's hockey
* Skiers in sleeveless tops as temperatures rise
* Organisers say relaxed about snow conditions
* Anti-corruption activist criticises Games
By Mike Collett-White
SOCHI, Russia, Feb 13 (Reuters) - Medals will be decided elsewhere, but the men's hockey competition is the big draw at the Winter Olympics on Thursday as heavyweights Canada and the United States, and host Russia, all play their opening round games.
With the weight of a nation on its shoulders, the home squad takes on Slovenia at the gleaming new Bolshoy Ice Dome in the Black Sea resort of Sochi, while Canada meets Norway and the United States play Slovakia.
The final of the tournament is not until hours before the closing ceremony on Feb. 23, but the men's hockey is the one gold that many Russians would dearly love to win above all.
Of the six medal events to be decided on Thursday, the first gold went to Joss Christensen of the United States in the inaugural men's freestyle skiing slopestyle. Gus Kenworthy took silver and Nick Goepper the bronze in a U.S. podium sweep.
That may help relieve the pressure on American athletes, amid early grumblings from U.S. media about the team's performance at the Games so far.
Writing before Thursday's action got underway, Los Angeles Times sports columnist Bill Plaschke wrote: "After six days of competition, despite being allegedly ready for this, the U.S. team is getting the hind parts of its snow pants kicked."
He listed a string of notable failures, among them speed skater Shani Davis, whose bid to win the Olympic men's 1,000 metre crown for the third Games in a row ended with an eighth place finish at the Adler Arena on Wednesday.
At the same venue on Thursday, the absence of injured four-times Olympic champion Wang Meng opens up the race for the women's 500m short track title.
Also going for gold on the sixth day of full competition at the sun-drenched Olympic park in Sochi are Americans Heather Richardson and Brittany Bowe, favourites for the women's 1,000 metres speed skating title.
SUNSHINE AND SNOW
In Sochi, balmy spring temperatures of 15 degrees Celsius (59 degrees Fahrenheit) and the sight of people bathing in the sea are not a problem for indoor venues.
Up in the Caucasus mountains, where the skiing events are taking place and the hills below them are bare, it is an issue.
On Thursday, several competitors in the women's cross country started the race in sleeveless tops, an unusual sight.
Organisers played down concerns about snow conditions that several athletes have described as slushy and difficult, and may explain some of the crashes in disciplines ranging from freestyle skiing slopestyle to cross country.
"It is a constant battle for winter sports," said Mark Adams, International Olympic Committee spokesman. "We are always trying to battle with a dynamic field of play. We are relaxed but we watch the situation."
The International Ski Federation said it had no concern about the ski jumps at the Olympics, despite two night-time training crashes, one of which sent an athlete to hospital.
In the mountain medals, Norwegian Ole Ainar Bjoerndalen aims for a record 13th Winter Games medal in the 20km biathlon, and compatriot and cross-country skier Marit Bjoergen goes for her second Sochi gold in the 10km classic race.
In the last event of the day, luge powerhouse Germany look destined to win the inaugural team relay.
Germany is already top of the medals table with six golds, ahead of Canada, the Netherlands, Norway and the United States who all have four. Russia is seventh with two.
The thrill of the action has gone some way to eclipsing the threat of Islamist militant attacks, international criticism of Russian laws banning gay propaganda among minors and allegations of corruption that marred the buildup to the Games.
Russia spent an estimated $51 billion on its first Winter Olympics, making them the most expensive Games ever held.
Officials dispute the figure, and say that many of the huge construction projects associated with Sochi will help turn the area into an international winter sports centre of the future.
President Vladimir Putin has staked his reputation on staging a successful Games, and says criticism levelled against the event has been reminiscent of the Cold War when he said the West sought to hold the Soviet Union back.
He has also dismissed charges of widespread corruption surrounding the Olympics.
Sergei Kolesnikov, a Russian biophysicist who campaigns to expose what he says is major corruption in the country, said during a visit to Washington this week that Sochi may not be the triumph Putin hopes it will be.
"I think underneath the Olympics drives many Russians crazy because the standard of life is decreasing," he said.
"Everyone is going to look back from this and remember only that $52 billion were thrown away for nothing ... Everybody knows how much money was stolen to make the Olympics happen, so what should we be proud of?" (Additional reporting by the Reuters Winter Olympics team in Sochi and Rosa Khutor and John Shiffman in Washington)