Curling is a precision team sport similar to bowls or bocce, played on a rectangular sheet of prepared ice by two teams of four players each, using heavy polished granite stones which players slide down the ice towards a target area called the house. Points are scored for the number of stones that a team has closer to the centre of the target than the closest of the other team's stones.

The game is thought to have been invented in late medieval Scotland, with the first written reference to a contest using stones on ice coming from the records of Paisley Abbey, Renfrew, in February 1541.

In the early history of curling, the rocks were simply flat-bottomed river stones which were sometimes notched or shape; the thrower had little …show more content…
The reason for this is that any dirt in the area or on the bottom of a rock could alter the trajectory of it and ruin the shot. When this happens, this is called a "pick".
After cleaning the rock, the next step is to know what rotation, or turn, to put on the rock. The skip will usually tell the thrower this information. The thrower will then place the handle of the rock generally at either a "two o'clock" or a "ten o'clock" position. When delivering the rock, the thrower will turn the rock from one of these two positions toward the "twelve o'clock" position before releasing it. A rock turned from ten o'clock to twelve will spin clockwise and curl to the right, and a rock turned from two o'clock to twelve will have the opposite effect. A generally desired rate of turn is about two and a half rotations before coming to a rest.

Once the thrower knows the turn to give the rock, the thrower will place the rock in front of his or her toe in the hack. At this point the thrower will then start his or her delivery. This begins by slightly rising from the hack, and moving the rock back to one's toe. This is the beginning of a pendulum movement that will determine the force given to the rock. Some older curlers will actually raise the rock in this backward movement, as this is what they are accustomed to. The forward thrust of