Curling is a team sport played on ice. Teams are traditionally made up of four players with the team captain called the skip. There are no skates. This Olympic medal sport, probably originated in the 1500's on the lakes and ponds of Northern Europe. Two teams of four players each slide 42-pound granite rocks down a sheet of ice 140 feet long by 15 feet wide (see Figure 1). The rocks are delivered from one end of the sheet to the other toward the center of a 12-foot diameter target called the house. Players wear shoes that grip. While delivering the stone, players slide on a slick, plastic slider attached to one foot. This gives the delivery a smooth effortless look.
Curling is played actively in more than thirty countries and on every continent. The majority of players live in Europe, Canada and the United States. It is mostly played indoors at dedicated curling facilities housing multiple sheets (lanes) of ice.
Curling can be enjoyed by nearly all age groups for social play as well as high-level competition such as the annual world championships and Olympic Games. Curling awareness has increased dramatically since the Olympic Games in Torino, Italy in 2006 where media coverage of the sport increased in the United States and Canada. With the 2018 games complete, many teams are preparing for competition in the Winter Games in 2022.
The object of the game is to score more points (rocks) than your opponent. In each end, like an inning in baseball, teams throw eight rocks each (two per player, alternating with your opponent) toward the twelve-foot diameter target called the house. All rocks closest to the center count as one point as long the opponent does not have one closer. The targets are usually painted into the ice just below the surface at both ends of the sheet of ice, allowing the game to be played back and forth, usually eight or ten times. Eight-end games take about two hours. Each player throws two rocks toward the target, alternating with the opponent. Rocks traveling down the ice will curl anywhere from six inches to six feet. After all sixteen rocks have been thrown the score is determined. Teams score one point for each rock closest to the center of the house without an opponent's rock closer. In each end, only one team can score. As the rocks are thrown, they are intentionally rotated clockwise or counterclockwise (depending on the shot). This rotation causes the rocks to curve (curl) as mentioned above.
A unique part of curling is the concept of sweeping. Players vigorously sweep, or brush the ice in front of the rock as it travels. The friction of the brooms momentarily changes the ice surface by melting and scratching a thin layer of the ice in front of the rock. This thin layer lubricates the bottom of the rock allowing it to travel farther and straighter. In recent years, the sweeping motion has been known to scratch the ice slightly helping to steer the rock. Good sweepers can manipulate the distance and curl resulting in rock placement.
Traditional Four on Four: Most games are played four against four, each player throwing two rocks per end. The number of ends varies depending on the level of play, generally eight ends or ten. In the four-against-four format, there are many different categories based on gender and age.
Mixed Doubles: A format that debuted at the 2018 Olympics is mixed doubles. The object of the game is the same but it is played two against two. One male, one female. Only five rocks are thrown per team in each end. One payer throws the first and last rocks while the other throws the middle three. The order can switch every end if so desired. Two rocks are prepositioned before play begins, one in the house and one in the free guard zone. Refer to the WCF rules for more detail.
Wheelchair Curling: The objective of wheelchair curling is the same. There are some basic rules that the curlers play by such as, no sweeping, the chairs must contact the ice surface, and you can deliver by hand or by throwing device. Wheelchair curling is also mixed gender. Also refer to the WCF website for more detail.
One-On-One: 2020 is the year one on one formats emerged. Of course, the one-on-one format has been used for years in informal practice-type settings.
Some History: As mentioned earlier, the game originated on the frozen lochs of Northern Europe several hundred years ago. There was a point in curling history where temporary enclosures were placed around the curling section of the frozen lake. This was done to protect the curlers from the elements.
Ice that is formed by cold air is known as natural ice. For natural ice to occur, obviously the temperature must be below 0 degrees C (32 F). This limited the growth of curling to the more southern latitudes. When the sport finally came to North America (early 1800's), it was primarily played in Canada, where the winter temperatures were consistently below freezing.
In the early 1900's, refrigeration technology allowed ice to be prepared in regions where winter temperatures are often above 32. This ice is known as artificial ice. Almost all curling facilities now have artificial ice, which allows curling to thrive in all latitudes.
Artificial ice is produced using a process of compressing ammonia or Freon and then allowing it to expand and cool. This cooling process removes heat from the playing surface, lowering the temperature, and creating ice. This is done by running cooling pipes under the playing surface. The pipes are usually four inches apart, run the length of each sheet, and carry cold liquid chilled by the ammonia or Freon. A four-sheet club has approximately six miles of pipe under the ice.
Curling in Warm Climates? Curling is slow to arrive in the middle latitudes. To date, dedicated curling facilities in warm climates (35 degrees North latitude and below) are few and far between. The refrigeration equipment and compressor is driven by one or more large capacity electric motors. These motors draw an enormous amount of electricity making it very expensive to make ice. Curling in these climates usually happens at ice rinks that share ice time with skaters, hockey players and curlers.
The Playing Area: The modern playing area is approximately fifteen feet wide by about 140 feet long. It's called a sheet. Rubber hacks are placed in the ice for foot traction for delivering the rocks. The dimensions of a sheet are subject to change from time to time.
The Hog Line: In addition to the perimeter lines, marking the boundaries of the playing area, there are important lines within the playing area that effect play. The hog line is the most significant demarcation. The hog line has two functions. The far hog line serves as the leading edge of the area in play meaning rocks must fully cross the hog line to stay in play during the end. The nearer hog line serves as the farthest edge of the delivery area, meaning all rocks must be released before they touch the near hog line. It's an odd name for a boundary line.
Anecdotal Explanation: The name hog line comes from an old Scottish shepherding term. Baby sheep are known as hogs. The line of slow-moving baby sheep (not pigs) at the trailing edge of the pack was referred to as the hog line. This line of sheep was the farthest back a sheep could be and still be part of the group. You can draw the distant similarity. In curling, it's the farthest point a rock can be from the center and still be in play.
Originally, the hog line was used only to determine in-play boundaries. It was not used as a release boundary since most deliveries were essentially from a stationary position the hack. As players began using the slide in delivery (1940s and 50s) rules were put in place to prevent a player from sliding the entire length and placing the rock in house. The near hog line seemed to be a suitable spot. Starting in the 1950s, the body was not allowed to cross the hog line during the delivery. In 1973, the international organization modified the rule stating the stone must be released before it touches the near hog line and the body would be allowed to slide past it. Today, the rock is removed from play if it touches the hog line prior to release and in some cases is measured by high tech sensors in the handles.
From a distance, curling ice appears perfectly smooth. After a closer look, you'll notice that the ice appears bumpy. The rocks ride on these small frozen bumps called pebble. The pebble is put on before each game with a machine that works like a flower sprinkler. Without the pebble, there would be too much friction between the ice and the rocks, making it too difficult to throw the rocks the full distance. Pebble is what makes curling a finesse game.
The ice is maintained between games by sweeping off debris and re-pebbling. The build-up of pebble is generally scraped off the surface two or three times a week, or as much as possible. A special scraping machine is manufactured just for curling ice. The resurfacing machine removes the build-up of pebble and any frost that has settled before new pebble is applied.
Occasionally, due to the uneven freezing of the surface, the entire area is flooded and allowed to freeze slowly. This levels the ice and is done about every six weeks or so.
It is very difficult to prepare a perfectly level ice surface. Even though most imperfections can't be seen, the way the rocks behave while in motion may indicate the presence of ridges and troughs. This is part of the game. Skips must determine what the sheets are like as early as possible, similar to reading the green in golf.
The ice surface temperature is maintained somewhere in the 22-25 degree F range. In some cases, sophisticated equipment is used to measure and maintain these temperatures.
New Era Curling Ice: Up until the mid-1980's, the ice surface was relatively crude. Ice was made with mineral-laden tap water. Pebble was added every game and built up over time. Corn brooms littered the ice with corn chaff and debris. The ice was relatively slow and straight (rocks didn't curl much) and games were played with mostly takeouts. A draw game was played by seniors.
Two major contributions or breakthroughs in the 1980's changed the game.
Purified ice and regular scraping completely changed the ice surface and therefore change the game. The ice was faster with more curl. Teams immediately took advantage by shifting from a takeout game to a draw game and the new era of curling began.
The Air: The air temperature in most clubs is controlled. The ideal air temperature at chest level is around 40-45 F. Not only is it comfortable for the curlers, the heat keeps the relative humidity lower so frost won't build up on the ice surface. Some clubs have dehumidification systems. This further decreases the relative humidity and dew point. Lower latitude clubs with no heating capabilities usually have frost problems. Higher latitude clubs with no heat are very cold and dry. In extremely cold and dry cases, the ice may sublimate. Sublimation is the process of ice changing to vapor without passing through the liquid stage.
Teams are made up of four players. The positions are traditionally called skip, vice skip, second and lead. The traditional name for a curling team is a rink. For example "The Smith Rink" would describe the team skipped by John Smith. This term is fading and most teams today are just called teams.
Each player throws two rocks, alternating with the opponent. Traditionally, the first position is known as the Lead and throws the first two rocks for the team. The second position is known as the Second and throws the second two. The third position is known as the Vice Skip and throws the third two rocks. The fourth position is known as the Skip (calls each shot and is essentially the team captain) and in most cases throws the last two rocks.
Quick Note: The role of the players determines the position names. The person calling the shots, managing the game and standing in the house is the skip. The person that takes over the skip's responsibilities while the skip is throwing is the vice skip. Throwing order has no bearing on position names.
The skip controls the game by determining the game strategy and calling all of the shots. Since the rocks curl as they travel down the ice, the throwers must aim at a point other than the intended target rock or resting point. The skip is responsible for providing an aiming point. He or she places the broom upright, directly over the desired aiming point. The skip is also responsible for determining whether sweeping is necessary on some shots and communicating this to the sweepers*
The use of a team coach is becoming more popular. Curling coaches are required to passively coach the team. Rules state that the coach cannot interact with the team during play. Even with the existence of a team coach, the skip must call all of the shots. Coaches generally communicate before, after and in some cases, during a break half-way through the game. Time-outs are another opportunity for coaches to intervene.
* On more skilled teams the skip is not responsible for determining sweeping on draw shots. The sweepers judge the distance and sweep when necessary (See the Sweeping section).
Essentially, there are only two types of curling shots, the draw and the takeout. There are many variations of these two shots, however.
Draws are shots that are only thrown hard enough only to reach the field of play at the other end. Takeouts are designed to remove rocks from play.
As mentioned earlier, we intentionally rotate the rocks as we throw them. These rotations are called turns. A clockwise rotation (for a right handed person) is called an In-turn while a counter-clockwise rotation is called an Out-turn. The names originally come from the direction your elbow took as you were throwing. (the elbow pointed out as you rotated the out-turn and vice versa). This is no longer appropriate because the elbow shouldn't move in a proper delivery. The names remain.
Below is a list of possible draw shots:
Below is a list of possible takeout shots:
All shots called by the skip have an associated hand or arm signal. Hand signals were developed due to the length of the sheet of ice (the option is to scream to players at the other end). Also, many curling clubs are so loud, making talking difficult.
Skip's signal can vary dramatically. Listed below are the most common signals used. There are two basic types:
Games consist of either eight or ten ends depending on the level of competition. League and bonspiel games are generally eight ends while championship games are ten ends. An end in curling is similar to an inning in baseball. Each end takes approximately fifteen minutes, so an eight end game would generally take two hours to play.
Each game, the teams are assigned a sheet of ice (similar to a lane in bowling) at the curling club. Curling clubs have anywhere from two sheets to eight sheets of ice.
In championship games, a short pre-game practice is allowed, generally six to ten minutes per team.
The Coin Toss
In championship games the hammer is not determined by chance. It is determined by the Last Shot Draw (draw to see who has last rock). This is done before each game. The winner of the draw contest chooses hammer or rock color.
Beginning of the Game
Note: In many clubs, the rocks are numbered from one to eight. Unless told otherwise, the lead should throw rocks number one and two, the second throws three and four and so on.
Each player will throw two stones per end, alternating with the opponent. Your team throws one; the opposing team throws one, and so on. As the lead is throwing, the second and vice are designated sweepers, with the skip calling the shots. When the second is throwing, the lead and vice are the sweepers. When the vice is throwing, the lead and seconds are sweeping. When it comes time for the skips to throw, the vice skip takes over responsibility of the house and calls all sweeping for direction. The lead and second remain as the sweepers for the skip's shots. Yes, the lead and second sweep more than the vice, and the skip doesn't sweep at all.
Position of Players
If you are about to deliver a rock, position yourself behind the hack and remain quiet and still as your opponent delivers. As soon as the opponent delivers the rock, choose your rock and move into the hack area. While the opponent's rock is still in motion, begin the setup process in the hack (described in the Delivery section).
If you are about to sweep, position yourself on the tee line approximately two feet from the sideline. Confirm the shot and weight with the thrower. As your teammate begins to deliver, start moving forward and to the center trying to meet the rock near the hog line. At this point you may begin sweeping the rock if necessary.
When you have stopped sweeping, return to the other end of the ice. Be sure not to walk down the center of the sheet, preventing the opponent from viewing. As you are walking back, try not to distract the opponent in the hack. If time permits, stop and remain still while the opponent is delivering.
Completing the End
After each end, when all sixteen rocks have come to rest, one team will score one point for every rock it has closest to the center. Only one team can score in an end. The scoring team gives up the hammer in the next end. If no team scores in an end, either deliberately or by accident, the hammer is retained.
After agreeing on the score, the vice skip of the scoring team is responsible for posting the score after each end. On the curling scoreboard, numbers 1 through 16 (possibly 17, 18, 19 etc.) are painted horizontally from left to right. These numbers represent the rocks scored. At one end of the scoreboard, there is a stack of individual numbers from 1 to 10. These represent the ends and are hung either over or under the painted numbers. Since teams throw different colored rocks, the ends are hung above or below the painted numbers depending on color. In curling, the rocks scored are posted cumulatively, meaning two rocks scored in the second end are added to whatever was scored in the first end (if any).
The team scoring in the end will give up the hammer and throw first in the next end. This means that the scoring team will never have last rock advantage after just scoring.
Finishing the Game
Conceding the Game
Rule of Thumb
Like golf, slow play is never appropriate. Fifteen minutes per end!!!
The clock begins when the opponent's rock comes to rest and the skip is allowed to take control of the sheet. The clock will continue to run until the next rock is thrown.
It is necessary for the lead and second to be ready to play when the opponent's rock comes to rest. This is a noticeable difference in the pace of the game. Teams under the clock no longer have the luxury of casually moving into the hack and taking their time. The pace at the beginning of end is usually faster than the pace at the end due to the vice skips and skips discussing the shots. The faster the leads and second are, the more time the back end has to discuss the strategy.
Equipment for Curlers
The broom or brush is used to sweep the ice (polish it, actually) and most curling clubs have brooms available for use. See the Advanced Equipment section for the CurlTech choice on purchasing a broom.
More advanced curlers may choose to purchase special curling shoes with a built-in slider. See the Advanced Equipment section for the CurlTech recommendation for curling shoes.
There are many manufacturers of curling equipment in the United States and Canada. Most veteran curlers choose to have their own curling equipment; shoes, brooms, special curling gloves, pants, jackets, etc. The list of equipment types and styles is endless. Consult your local curling trainer or curling professional for advice on appropriate equipment.
Equipment for the Curling Club
The Spirit of Curling
The previous text was taken verbatim from the World Curling Federation (WFC) curling handbook. The Spirit of Curling is familiar to all who curl and its principles guide the sport.
Curling is one of the few sports in the world that emphasizes etiquette. All games, regardless of level, start and finish with handshakes. In most league play, there are no referees or judges. Adhering to the rules is based on the honor system and good shots are admired by all. Missed shots are never cheered. Now that you are familiar with the time-honored spirit of curling, let's apply it to a real game.
Curling is a medal sport in the Olympic winter games. This status has increased the competitive nature of the game, as well as overall interest in the sport. Despite the competitive aspect of the game, curling remains a highly social and gracious sport for all age groups.
Broomstacking and the Competitive Spirit
Broomstacking at all levels leads to the development of world-wide social networks. Lifelong relationships are developed and forged through the broomstacking concept.
Even at the competitive level, many teams play against each other so often that they become friends. To prepare for the 2018 Olympic Men's Gold Medal Game (USA vs. Sweden), Team Shuster and Team Edin had a friendly chat over Facetime about their upcoming big game and wished each other luck. These two teams had played each other so many times, that they were friendly enough to invite each other to their weddings (a couple guys on Sweden's team went to Matt Hamilton's wedding). This is a true and amazing example of the competitive spirit and friendly nature of the game.
The sort of curling has been played for hundreds of years. It has only been in the last fifty or so years that curling has seen any significant innovation. The following is a list of curling innovations: