Although the sport of curling dates back to the early part of the 16th century in Scotland, it didn't become an Olympic medal sport until 1998 in Nagano.

Sometimes compared to shuffleboard, curling is played by sliding heavy stones on ice. In the 16th century, those stones -- which now at regulation weight are 42 pounds -- were used on frozen ponds, lochs and marshes.

Unlike other winter sports such as skiing, luge, figure skating or speedskating, curling has organized clubs. The sport has been enhanced by the friendships that are formed throughout several competitions.

Curling takes place between two teams with four players on each squad. The game is played on ice, and the two teams take turns pushing the 42-pound stone toward a series of concentric circles. The object is to get the stone as close to the center of the circles as possible. The center of the circles is known as the "tee." A team scores a point for each stone that is closer to the center circle than the opponent's best stone, provided that the stone is within 6 feet (1.83 meters) of the tee. This circular area is known as the "house." It is the scoring zone in curling. A game is made up of 10 ends, just like innings in baseball.

The basic components of the 500-year-old ice sport are delivery of the stone, sweeping along its path and strategy. Special brooms are used to sweep the ice for friction to create more or less speed for the rock.

The team's skip is the strategist and must study the ice, judge the amount of curl, and call the shots. That person holds the broom as a target for shots by the other three players. Skips usually throw the last two rocks of each end.

The men's and women's tournaments will consist of 10 teams, each competing in a round-robin tournament. During the preliminary series, each team will play against each of the other teams. Based on the results of the round-robin, teams will advance to the semifinals. The winners of the semifinals will play in the gold-medal game. The losers of the semifinals will play for the bronze medal.

The curling competition starts on Monday, Feb. 13. The women's bronze and gold medal matches are scheduled for Thursday, Feb. 23, while the men's bronze and gold medal matches are the following day. Curling will be held at Pinerolo Palaghiaccio, which is about 30 miles southwest of Torino.

TOP CONTENDERS AND CURRENT CHAMPIONS

Although the sport is probably most popular in Canada, the men's Olympic titles have gone to Switzerland (1998) and Norway (2002). The Canadians have finished with a silver each time.

Pal Trulsen leads the Norwegians as the team's skip and has led his squad to a fifth place finish or better at every world championships since 1999. The 43-year-old Trulsen, back for his third Olympics, is joined by teammates Lars Vaagberg, Flemming Davanger, Bent nund Ramsfjell and Torger Nergard.

Finland's Markku Uusipaavalniemi heads another potential international threat for men's curling gold. His teams have finished no worse than fifth at the world championships since 2000. Wille Makela, Kalle Kiiskinen, Teemu Salo and Jani Sullanmaa are also on the Finnish men's team.

Ralph Stockli heads the Swiss men's team, which also won a bronze medal four years ago.

In the women's division, Great Britain claimed the gold in 2002, while Switzerland won the silver and Canada the bronze. The Canadians won gold in 1998.

Rhona Martin skipped the British women to the title in 2002 and will return this year. She'll be joined by Kelly Wood, Jackie Lockhart, Lynn Cameron and Deborah Knox.

What may give the Brits an advantage is technology. They have reportedly been using state-of-the-art brooms that have a memory card and sensors. They're apparently being used to review how sweeping forces of athletes can help the stone slide to the target.

U.S./CANADIAN OUTLOOK

Canada stands an excellent chance at sweeping the gold in both the men's and women's divisions. Brad Gushue skips the Canadian men. The 25-year-old's team barely won the national championships in December. Gushue will be the youngest man to skip a Canadian team at the Olympics. He'll be joined in Torino by Mark Nichols, Russ Howard, Jamie Korab and Mike Adam.

Shannon Kleibrink, Amy Nixon, Glenys Bakker, Christine Keshen and Sandra Jenkins make up the Canadian women's rink. Kleibrink, who serves as the skip, pulled off some upsets at the national trials. In fact, her team lost three of the first four matches before putting together seven consecutive wins to earn a berth in Torino.

The Americans have a daunting task if they are to medal in curling for the first time at the Olympics.

The owner and operator of a pizza shop in his hometown of Bemidji, Minn., Pete Fenson will skip the U.S. men's team. Fenson's team came in sixth at the 2005 World Curling Championships after beating New Zealand, which qualified the squad for the Olympics. Also on Fenson's team will be Shawn Rojeski, Joseph Polo, John Shuster and Scott Baird.

For the second straight Olympics, the U.S. women's team will be led by a sister tandem. In 2002, Kari Erickson and her sister, Stacey Liapis, were on the team that finished fourth. This time, it's Cassie and Jamie Johnson headlining the "Curl Girls" in their effort to bring home a medal. Read More About The Johnson Sisters. They're joined by Jessica Schultz, Maureen Brunt and Courtney George.