a: hack - b: back line - c: button - d: tee line - e: centre line - f: hog line - circles: house
The game of curling is played on ice with (approximately) 42-pound granite stones. The playing surface - a 'sheet' - is 138 feet long from hack to hack, and just over 14 feet wide, with a house at both ends. In each 'end' of the game 16 stones are played, 8 by each team, and at the conclusion of the end, the team with one or more stones closer to the button than any opposition stones, scores the equivalent number of points. Each of the four members of a team delivers 2 stones each, one at a time, alternating with the opposing team. The stones are delivered from the hack at one end of the sheet to the house at the other end, by the player pushing off from the hack with the stone, and releasing it with a spin - 'curl' - which gives Curling its name. When delivering a stone, one can play a 'draw', which means the stone comes to rest somewhere in the playing area, or a 'takeout', whereby the delivered stone takes out an opposition stone. A draw stone that comes to rest in front of another stone, thereby making it difficult for the opposition to remove the guarded stone, is called a 'guard'.
THE CURLING ROCK
The original curling stone - or 'rock' - used in Scotland, was just a large chunk of rock, without any particular size or shape (see History of Curling) bowled across the ice. This evolved into the 42 pound rocks we use today, which are made of granite and shaped and polished to a specified size and shape, concave on both upper and lower surfaces. On some stones the degree of concavity is different on the two sides, allowing for reversal of the stone for 'faster' or 'slower' ice. A handle, usually on a circular plastic disc, is bolted onto the stone by way of a channel running through the middle of the stone.
Each stone is delivered from the hack, which is basically a rubber covered foot rest embedded in the ice surface. First, the stone is pulled backward where it may or may not be lifted off the ice surface, and then the curler and the stone glide forward together, the curler in stretched out pose. The stone must be released before it crosses the hog line to continue its glide toward the house at the other end of the sheet. The stone is released so that it rotates during its glide down the sheet, and this rotation makes it move gradually sideways, much like a very slow curve ball. This lateral motion is called 'curl'.
A team consists of four players, called the 'lead', 'second', 'third' and 'skip', and they each deliver two stones in that order. The skip, as the name indicates, is the team captain, who decides where he/she wants the particular stone to end up, holds his/her broom for the deliverer of the stone to aim at, and directs sweeping. When it is the skip's turn to deliver stones, the third temporarily acts as skip. The two team members that are not delivering a stone may be called on by the skip to sweep in front of the delivered stone. Such sweeping will both make a stone travel farther and reduce its curl, and so, can be used to assist the stone to behave in the manner desired by the skip. Vigorous sweeping requires curlers to be fit, and in a typical two hour game a curler walks almost two miles.
Prior to games the sheet is sprinkled with water, which freezes and produces a pebble like surface. Without this pebble the concave shape of the stone would work as a suction cup, but with it, the rotating stone curls nicely down the sheet. Ice making for curling requires both art and science, involving control of temperature, air moisture content, purity of water, and pebbling among other things.
Curlers always insist the game to be one of strategy, and not only because they want to be seen as doing more than just throwing rocks and slipping around on ice. A great deal of thought and effort goes into ensuring that your team has one or more stones closest to the button at the conclusion of each end. This can be accomplished by having the stone delivered with just the right speed, so that it stops where you want it to in the house - a draw as seen to the left, where the rock stops on the button.
Or an opposition stone can be removed from the playing area by hitting it with one of yours with enough force to remove it out the back of the house - a takeout, as illustrated below.
And once one or more of your stones is positioned where they may be scoring stones, you can deliver a stone so slowly that it stops in front of the potential scoring stone(s), making it difficult or impossible for the opposition to remove the scoring stone(s) with a takeout - a guard (below):
Since each team delivers 8 stones, the maximum score in any one end is eight, but typically, one to three points are scored. Games consist of 8 or 10 ends, lasting 2 or 2.5 hours, i.e. approximately 15 minutes per end.