What is Curling?

History
Gameplay
Strategy
Scoring
Equipment
Spirit of Curling
Helpful Links

What is Curling?

The Basics

Curling is a game involving two four-player teams, granite stones, brooms, and a sheet of ice. All players alternate sliding stones towards a circular target area, called a "house", while their teammates sweep the ice and the skip shouts instructions. The score for each round, or "end", is determined after all 16 stones are thrown, based on whichever team's rock(s) is closest to the middle of the house. Games are eight ends long and take about two hours to play, excluding Olympic-level games which are 10 ends.

History of Curling

Curling originated in Scotland in the 1600s with players sliding stones on frozen rivers. The irregular bumps, snow, and debris on the ice and stones meant these early curlers had little control over the stone's path, making the game more luck than skill. Over time the stones gained handles, consistent shapes and weights, and eventually the sport moved indoors, culminating in the modern game you see today!

Gameplay

A game of curling consists of 8 to 10 “ends”, like innings in baseball, where the teams alternate shots with every player throwing two stones per end. Positions are named after the order the players throw: Lead, Second, Third (or Vice), and Fourth, who is almost always the team's Skip. The Skip spends most of the game in the house making the strategy decisions and shouting instructions at the sweepers, which is what the other players do when they aren’t throwing. When it’s the Skip’s turn to throw, the Vice takes over the shouting from the house.

There are three components to throwing or delivering a stone:

Weight - the speed of the stone
Turn or Handle - the rotation of the stone
Line - the direction of the throw

The stone must be released before its front edge crosses the near "hog line", and it must completely pass the far hog line or it is removed from play. This is called a "hogged shot" or "hogging".

Skips tell their teammates to attempt one of three types of shots:

Guards – Placing a stone in front of house to prevent a take-out. These are the slowest shots.
Draws – Placing a stone in the house.
Take-outs – Hitting an opponent’s stone out of play. These are the fastest shots

You’ll often hear other names for shots (peel, freeze, raise, run-back, etc) but they are all variations of the three basic shots. One of the key components of curling is that every stone is thrown with a clockwise or counter-clockwise rotation which causes the stone’s path to curve or curl as it travels down the ice, and slower moving stones curl more than faster moving stones. This allows a draw to curl behind a guard, while a faster moving takeout cannot. In the image to the right, the red stone is a guard, and the blue stone is a draw that curled around it.

Strategy - The Hammer

The last rock thrown in each end is so important it has its own name: the “hammer”. It is much easier to score with the hammer – so much so, that in the 2018 Olympics, teams with the hammer scored 90% of the time! Teams with the hammer tend to play more aggressively and try to score multiple points in an end, while the team without the hammer will play defensively and try to “steal” a point. The hammer switches teams throughout the game, going to whichever team did not score in the previous end (in the first end the hammer is usually decided with a coinflip).

Teams are so committed to scoring multiple points with the hammer that they will often “blank” an end by ensuring neither team has any rocks in the house, which means neither team scores. This allows them to keep the hammer and try for multiple points in the next end. As a result, it’s considered a win for the other team to “force” the hammer team to score only one point and give up the hammer. Teams will also blank ends for other reasons, including ensuring they have the hammer in the final end of the game.

These opposing goals lead to contrasting strategy for the two teams in each end – the hammer team will try to leave the middle open for the final hammer shot, while the other team will try to clog up the middle with guards and “bury” one of their rocks behind guards at the center of the house.

Strategy - The Free Guard Zone

The Free Guard Zone is a rule implemented only a few decades ago to make curling games more exciting and strategic. The Free Guard Zone prevents a team from knocking the opposing team's guards out of play for the first five rocks of each end. If a guard is knocked out of play, it simply goes back to its original location, and the thrown rock is removed. Rocks in the house are still allowed to be removed at any time. Before this rule was created, many teams with leads would take out every stone and blank the entire second half of games.

With this rule, it gives teams time to place guards and draw behind them before the other team can take out the guard. This results in more rocks in play and higher scoring games, making a more entertaining game to both watch and play.

Scoring

The goal in curling is to have your stones closest to the "button", or the center of the house, at the conclusion of each end. Only the team whose rock is closest to the button can score, and they earn one point per stone closer to the button their opponents' closest rock. That's a mouthful, so here are a few examples to help explain:

A rock must be in the house to score, which includes any rock partially inside the house. If a stone is not at least the touching the outside ring of the house then it does not count. If no rocks are in the house at the conclusion of an end, the end it is "blanked" and no one scores. As described in the Strategy section, sometimes it's advantageous not to score.

While Olympic games now use a baseball-style scoreboard, most curling clubs use one that's similiar but 'backwards'. The numbers in the center row indicate the points, and the numbers above and below represent the end the team reached that many total points. So in the example below, Red is winning 4 to 3 against Blue. Red scored 2 points in the 2nd end, and 2 more points in the 5th end, giving them a total of 4. Meanwhile, Blue scored 1 point in each of the 1st, 3rd, and 4th ends for a total of 3. If there were any blank ends, the end marker would be hung on the top left, next to the Blank label.

Keeping score this way has a few advantages. You can quickly tell who is winning by whichever team has an end marker furthest to the right, and easily tell the difference in score without needing a separate running tally like in baseball. Furthermore, it requires only one set of number markers, 1 through 8, which is helpful as curling is generally a low scoring game with 0, 1, or 2 points scored most ends. If we were using a baseball-style scoreboard in the example above, we'd need three 1 markers and two 2s, and the game is only half over!

For more information about scoring, please see Potomac Curling Club’s Scoreboard 101.

Equipment & Playing Surface

The curling stone, also called a rock, weighs about 42 pounds and is 12 inches across. The bottom of a stone is concave, so only a small ring of the stone comes in contact with the ice. Originally the material for all curling stones came from islands off the coast of Scotland, but now some are from Wales too. That's because very few types of granite have the right density to meet the size and weight requirements with enough strength to stand up to repeated hits from other rocks!

The playing surface is called a "sheet", as in a sheet of ice. Each sheet is 146 feet long and 14 feet wide with a house at each end - for scale, here's how that compares to a hockey arena. The house is 12 feet wide and consists of three concentric rings unimaginatively called the four-foot, eight-foot and twelve-foot rings. The rings are only a visual aid for judging which stone is closer to the center and do not affect scoring, but a stone must be at least partially touching the house to score. The center of the house is known as the "button", and a shot intended to stop at the very middle of the house is called a "draw to the button".

Unlike smooth hockey ice, curling sheets are sprayed with water droplets which form a bumpy "pebble" upon freezing. The stone skips across the top of the pebble as it moves down the ice which helps the stone to curl. The pebble wears down over the course of the game which can affect the amount of curl, and sweepers intentionally wear the pebble in ways to influence the curl and distance of their shots. The sheets are scraped and re-pebbled prior to each game.

Curling shoes are similar to ordinary athletic shoes except the soles don't match - each pair has a sliding and a non-sliding sole. The sliding shoe is worn on a player's non-dominant foot and has a slippery sole, usually teflon, which is necessary for sliding when throwing, while the other shoe has a rubber surface for better traction on the ice. Many curlers will put a removable "gripper" around the sliding shoe between throws to have better traction when sweeping.

Spirit of Curling

Curling is a game with a strong tradition of sportsmanship, which is called the "Spirit of Curling". The most prominent examples of the Spirit of Curling are:

Before games all players shake hands, introduce themselves, and say "good curling" to all members of the opposing team.
Curlers congratulate throwers for all good shots, including their opponents' shots, and never celebrate a bad shot by the other team.
Similiarly, shouting or slamming brooms in anger is not tolerated.
There are no referees or umpires, even at the Olympic level; curlers call fouls on themselves.
Curlers never distract their opponents while throwing with movement or sound.
At the end, or when a game is out of reach, the losing team is expected to concede to the winners by shaking hands again.
Last, but certainly not least, it's tradition for the winners to buy the losers a round, called "broomstacking"!