Curling stems from Scotland where the game first started in the 16th century on frozen ponds. Eventually it made its way to North America with clubs popping up in Canada and the U.S. in the early 19th century.
The game is played with two teams with four players each for the men and women. There is also a mixed doubles tournament with one man and one woman. The U.S. has qualified teams for all three events at the Beijing Olympics.
The curling sheet, or playing surface, is roughly 46 meters long and 5 meters wide with houses, or rings, on either side.
Instead of a smooth layer of ice, like on an ice-skating rink, the ice for curling is covered with frozen water droplets or “pebbles” to help the stones curl.
Each curling rock is really 44 pounds of granite which is concaved on the bottom. After one player pushes the stone, other teammates then work with brooms to warm the ice’s surface with the goal landing a stone in a target at the far end or positioning the stones to act as guards.
There are ten rounds per match for men and women. There are eight for mixed doubles. These are called ends. It’s easier to think of them like innings in baseball, except the teams go back and forth sliding their rocks down the ice rather than having one team throw all of theirs first, then the other.
PLAYING THE GAME
In men's and women's, each team gets eight stones per end. In mixed doubles, it's six stones each per end.
The players push their rock down the ice, making sure to release before the stone reaches what is called the hog line. If a player does not release the stone before this line, then it is a violation and it is not counted.
From there, teammates use brooms to sweep the ice’s surface. The friction from the brush warms the ice’s surface and provides control. Neither the brooms nor the players’ feet may touch the stone.
They are aiming for the house – a target at the far end. The bullseye in the middle is the button.
For the men's and women's team competitions, the team member designated as the "lead" releases the first two stones and specializes in placing them close to the house. Then the “second” throws the third and fourth stones. This person specializes in placing stones to protect their first two stones from their opponent. The “third” then throws the fifth and sixth stones and is skilled at knocking off the stones of their opponent, while keeping their own stones in play.
The fourth person is the “skip” and throws the final two rocks. This person determines team strategy and is essentially the team captain. The skip aims to get the most points possible with those final rocks. When they aren’t throwing the rock, the skip is usually yelling sweeping instructions to their teammates.
In mixed doubles, one of the six stones for each team is pre-placed near the target at the start of each end. Of the remaining five stones, one player shoots the first and final ones while the other shoots the three in the middle.
While the casual fan might think each circle in the target is worth a certain number of points, that’s not the case. The most a team can get is one point per stone. But how many total points they get in an end depends on which stones are closest to the middle.
During each end, only one team may score. The team with the most stones closest to the button can win points. For example, if Team A has a stone sitting on the button and Team B has the next closest stone just one inch beyond that, then Team A would be awarded one point.
But if Team A has three stones closer to the button than any of Team B’s stones, Team A gets three points and Team B gets none.
If both teams fail to place a stone in the house, nobody gets points for that end.
The team that fails to get any points in an end is awarded the hammer. That means they get to throw last in the next end, which is the strategic advantage. If nobody scores in an end, then the hammer is awarded based on the most-recent end in which a team scored.
If the match is tied after all the ends are played, then it goes to extras until there is a winner. But, a team can also choose to concede a match if it believes it is so far behind, there is no way to catch up to the team in the lead.
The shoes curlers wear appear normal, but they are actually equipped with Teflon sliders on the bottom to help the curlers glide across the ice. Some, though, just buy a regular pair of shoes and add Teflon themselves.
Two different types of brooms are allowed. The first, and more common one, is a “push broom.” Also allowed is a corn broom, which looks like a normal straw broom. This was used mainly prior to the 1950s, as they were the common household brooms during that time.
Travis Pittman contributed to this report.