The world\'s top 16 ice hockey nations square off in the 76th ice hockey world championships starting in Finland and Sweden on Friday. Reigning champions Finland are trying to overcome the misfortune that has beset hosts of the world championships in recent decades as they seek to become the first team to win gold on home ice since the Soviets in 1986. They will also try to defend the world title on home ice for the first time since the Soviet\'s all-conquering Red Machine in 1979. However, they face tough challenges from hungry pretenders headed by Vancouver Olympic champions Canada, last year\'s runners-up Sweden and the traditionally strong teams of Russia and Czech Republic dreaming to storm all the way to the top. This year international ice hockey\'s ruling body IIHF has changed the format of the annual tournament, which will be co-hosted by two countries for the first time in modern history. And it will be the first time since 1997 that the men\'s world championship - the biggest annual winter sports event worldwide - will be played with two preliminary round-robin groups with eight teams in each. Finland\'s capital Helsinki will stage the championship\'s matches at the 13,350-seat Hartwall arena, while the group which is based in Stockholm, Sweden, will play its matches at 13,850-seat Globen arena. The new format sees the top four teams in each group advance into the last-eight round. The quarter-finals will be played within the respective groups as opposed to the cross-over system. Bottom-placed teams in each group will be relegated to Division One and replaced by Austria and Slovenia in next-year\'s tournament. Two quarter-finals will be played in Helsinki and two in Stockholm. Both semi-finals, bronze medal game and the championship\'s final will be played in Helsinki. Defending champions Finland are teamed up with both North-American giants Canada and the United States, Switzerland, Slovakia, France and two former Soviet Republics - Belarus and Kazakhstan in the group based in Helsinki. Stockholm will stage the matches of the other round-robin group comprising the hosts Sweden, Russia, last year bronze medalists Czech Republic, Germany, Norway, Latvia, Denmark and Italy. This year\'s world championship will also determine the seeding for the men\'s Olympic ice hockey tournament in Sochi 2014 for all countries participating in the Olympic qualification campaign. After the end of the championship nine top-ranked teams will earn a direct entry to the 12-team Olympic tournament in Sochi. The three other participating teams will be determined in three final Olympic qualification tournaments in 2013. The championship title winner will be decided in the final in Helsinki on May 20.