How Curling Works

Before the Shot

As the person delivering the shot steps up to the hack, the foothold located behind the house that is used to push off, she looks to the far end of the sheet for instructions. Another player, usually the skip (captain), is stationed behind the button on the far end of the sheet to determine the weight (the speed the stone moves down the ice), turn (which direction the stone will spin) and line (where the stone will curl) for the shot. The skip communicates the type of shot that should be used and the distance it should travel with a series of hand and arm movements, and uses a broom to mark the shot where the shooter should aim.

Delivery

From a kneeling position, with a foot flat on the ice, the player with the stone begins a shot by sliding forward and releasing the stone before crossing the hog line, painted under the ice. The player delivering the stone gives it a slight spin upon release, depending on which direction they want it to travel. For a right-hander, an in-turn will curl clockwise, while an out-turn will curl counterclockwise. For a left-hander, the opposite is true. Once the stone is released, the shooter’s job is finished. The stone is now in play and the team begins working to get it as close to the target as possible.

The spin allows the stone to travel in a curved path, or curl, as it approaches the house. The ideal amount of spin will cause the stone to make no more than three complete rotations as it travels the length of the ice. How much a stone curls depends on the amount of spin, the speed of the stone and the ice conditions. The faster the stone is traveling, the less it will curl.

Communication

Immediately after release, the skip yells to the other two teammates, telling them whether or not the line is good and whether adjustments are needed. Running up the ice with the stone are two sweepers who tell the skip whether the shot is heavy (hard) or light (too soft). The skip might yell, “sweep!” directing the brooms to polish the ice. The skip and sweepers yell back and forth, communicating what they see and doing their best to guide the stone to the intended spot.

Sweeping

The primary method to assist a stone’s movement down the curling sheet is sweeping in front of its path. Players may not make contact with the stone, but with guidance from the skip, they can clear the ice in front of the stone to enable smooth movement. The sweeping motion briefly polishes the ice (pebble) just before the stone travels over it, melting a molecular layer of ice for a very brief moment, and generating a thin layer of water. This creates a lower friction environment, allowing the stone to travel further. Sweeping cannot make a stone move faster, only farther.