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Hammer, Power Play and More: Common Curling Terms, and What They Mean

NBCUniversal Media, LLC

One of the most popular sports in the Winter Olympics, curling has drawn plenty of attention since it was added to the program, but there are a lot of terms that casual fans of the sport may not know.

To help with that, we’ve compiled a quick glossary of terms that you are likely to hear during curling broadcasts on NBC 5, USA Network, and Peacock.

4-Foot Circle:

At its most basic level, the “4-foot” is the innermost ring in the house, and is typically red in color. It surrounds the “button.”

The next ring out, which is usually white, is called the “8-foot,” and the ring outside of that, which is typically blue, is the “12-foot.”


Essentially, this is the center circle, or the bullseye, of the house. The team with a stone closest to the button earns points at the conclusion of each end.

Center Line:

This line is oriented vertically down the length of the sheet, moving directly through the middle of the button.

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Each curling match is divided into a set number of “ends,” which function like periods or innings.

In mixed doubles, there are eight ends, while in the men’s and women’s tournaments, there are 10 ends.

Each team also has a set number of stones that they get to throw during each end. In the men’s and women’s tournament, each player throws two stones, for a total of eight stones per team per end.


The “guard” is a stone that is placed in front of another stone to help protect it from being hit by the opposing team. These can either be placed prior to an end beginning, or can be thrown during the end to protect other stones.


The “hack” is the raised foothold, similar to those used in track and field, that is used by the athlete to push off before a delivery.  


The team that gets to throw the last stone in a given end is said to have the “hammer.” When a team scores points in an end, their opponent gets the “hammer” in the next end.

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Hog Line:

There are two horizontal lines on the ice known as “hog lines.” The one nearest the person throwing the stone marks the point where the stone must be released. The one closer to the house marks the point that a stone must reach in order to remain in play after it is thrown.


The house is the area beyond the far hog line where points can be scored. It includes the concentric circles around the button.

Power Play:

In mixed-doubles curling, each team is given the option to use one “power play” per game.

In a game of curling, two stones are placed on the sheet ahead of the end. The power play allows a team to position those stones in a way that could potentially allow them to score multiple points during an end.

During a power play, the team that elects to use the power play is allowed to position their “in-house” stone on the tee line, with half the stone in the 8-foot circle and the other half in the 12-foot circle.

The guard stone, placed by the opponent, is then positioned to the side of the sheet in line with the “in-house” stone, so that a vertical line could be drawn between the in-house stone and the hack.

A team has to be in possession of the hammer to use their power play.

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Shot Stone:

The “shot stone” is the stone that is closest to the button during a given end, indicating that the team is in position to score points.


Effectively the team captain, this player usually throws the last two stones in a given end in team curling.


The large, circular hunks of granite that are used to compete in curling. Also commonly known as "rocks."


“Sweeping” is, as the name would indicate, the job of using the broom to brush the ice in front of a moving stone, which allows it to travel farther or to curl less.

Tee Line:

This line goes horizontally across the house, dissecting the button into two halves.

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