Curling is a team sport played on ice where two teams of four players take turns sliding heavy granite stones toward a circular target called the house. The goal is to land your stones closer to the center of the house than your opponent’s. A standard competitive game lasts 10 ends (similar to innings in baseball), though many league games play 8 ends and take about two hours.
The Ice and the Target
A curling sheet is roughly 150 feet long, a narrow lane of carefully prepared ice with specific markings that govern gameplay. At each end of the sheet sits the house: a set of concentric rings with radii ranging from about six inches at the very center (called the button or pin) out to about six feet for the largest ring. Stones must be touching or inside these rings to count for scoring.
Two other lines matter most. The hog line, located between the delivery area and the house, is the point by which a player must release the stone. If you’re still holding the stone past the hog line, that shot doesn’t count. The hack is a foothold embedded in the ice at the far end of the sheet, essentially a starting block that players push off from when delivering their stones. Between the hog line and the house is the free guard zone, an area where specific rules protect certain stones from being knocked out of play early in an end.
Teams and Turns
Each team has four players, and each player throws two stones per end, alternating with the opposing team. That means 16 total stones are thrown in each end, eight per team. The four positions are called the lead, second, third (or vice-skip), and skip. The lead throws first, followed by the second, then the third, and finally the skip.
When a player isn’t throwing, they’re either sweeping or directing strategy. The skip typically stands at the far end of the sheet near the house, reading the ice and using a brush to indicate where the stone should be aimed. The skip is the team’s strategist, calling the shots and deciding whether the team needs an offensive or defensive play. When the skip throws, the third usually takes over that role at the house.
How to Deliver a Stone
Curling stones weigh roughly 40 pounds, and delivering one is a precise, athletic motion that starts from a standstill and ends in a gliding release. The process begins in the hack, where the thrower places the ball of one foot against the foothold and positions the stone on the ice in front of them, lined up with the skip’s target brush at the far end.
From there, the player rises into a semi-crouch, pulls the stone back along the intended line, then drives forward off the hack foot. The other foot, fitted with a special low-friction sole, slides along the ice as the player glides forward in a deep lunge, trailing leg extended behind. The throwing arm stays slightly bent, and the player’s eyes stay fixed on the target throughout. Just before the hog line, the player releases the stone with a slow, deliberate rotation of the handle, either clockwise or counterclockwise. That rotation is what makes the stone curl.
Why the Stone Curves
A curling stone doesn’t travel in a straight line. The gentle spin applied at release causes it to gradually arc left or right as it slows down, a behavior that gives the sport its name. A stone spinning counterclockwise will curl to the left; clockwise, to the right. This curling motion is what makes the game so tactically rich, because players can bend shots around obstacles or tuck stones behind guards.
The degree of curl depends partly on the ice surface and partly on what the sweepers do. Curling ice isn’t smooth. It’s covered in tiny frozen water droplets called pebble, which create a textured surface the stones ride across. As the stone slows, the curl becomes more pronounced, which is why the final few feet of a stone’s path often show the sharpest curve.
What Sweeping Actually Does
Sweeping is one of the most misunderstood parts of curling. It looks odd, but it serves a real physical purpose. When sweepers vigorously brush the ice in front of a moving stone, they momentarily raise the ice’s surface temperature through friction. That tiny temperature increase reduces friction between the stone and the ice, allowing the stone to travel farther and straighter than it otherwise would.
Sweeping can also smooth out frost or debris on the ice surface, further reducing resistance. The effect isn’t huge on any single stroke of the brush, but sustained sweeping over a stone’s full path can add several feet of distance and noticeably straighten the trajectory. The skip reads the stone’s speed and line, then shouts instructions to the sweepers: sweep hard to keep it straight and carry it farther, or lay off to let the stone curl more. This real-time adjustment is one of curling’s most skilled elements. Two sweepers working in sync can meaningfully alter where a stone ends up.
Scoring at the End of Each End
Once all 16 stones have been thrown in an end, only one team scores. The team with a stone closest to the pin (the very center of the house) earns points. They get one point for that closest stone, plus one additional point for every other stone of theirs that sits closer to the pin than the nearest opposing stone. Stones must be touching the rings to be eligible.
So if your team has three stones in the house and all three are closer to the center than the opponent’s nearest stone, you score three points. If neither team has a stone touching the house, no one scores, and the end is called a blank end. Blank ends aren’t always accidents. A team might intentionally blank an end to retain a strategic advantage called the hammer.
The Hammer and Basic Strategy
The hammer is the last stone thrown in an end, and it belongs to whichever team didn’t score in the previous end. Having the hammer is a significant advantage because the final shot can displace an opponent’s stone or place yours perfectly without any response. Teams will sometimes deliberately avoid scoring (blanking the end) so they keep the hammer for the next end, where they can aim for a bigger payoff of two or more points.
Three types of shots form the backbone of curling strategy. A draw is a shot designed to stop inside or in front of the house, the basic scoring play. A guard is a stone placed deliberately in front of the house to shield a scoring stone from attack. A takeout is a shot that removes an opponent’s stone from play entirely. A takeout aimed specifically at a guard is called a peel. Most of curling’s complexity comes from layering these three shot types into sequences that build an advantage across each end.
The Stones Themselves
Curling stones come from only two places on Earth: Ailsa Craig, a small island off the Scottish coast, and the Trefor granite quarry in Wales. Both sources produce dense igneous rock that formed millions of years ago. Ailsa Craig’s granite is around 60 million years old, while Trefor’s dates back 400 to 500 million years.
Each stone is actually made from two types of granite. The running surface, the narrow band on the bottom that contacts the ice, is typically made from Ailsa Craig blue hone. This variety has small, uniform mineral grains that resist being plucked out by the ice over years of use, and it’s relatively nonporous, so water doesn’t seep in and cause fractures. The body of the stone and its striking surface use a different granite (Ailsa Craig common green or one of the Trefor varieties) with more variation in grain size, which actually helps absorb the impact when stones collide. Conventional wisdom long held that these granites were ideal because they lacked quartz, but geological analysis has found quartz in all four types. The stones hold up so well likely because the rock is geologically young enough to have avoided the tectonic stresses that would introduce internal fractures.
Footwear and the Ice
Curling shoes are uniquely asymmetric. One sole is a slider, typically made of Teflon, that lets the player glide smoothly across the ice during their delivery. Sliders range in thickness from extremely thin (for beginners who want more control) to a quarter inch thick for experienced players who want a faster, longer slide. The other shoe has a grippy rubber sole, like a winter tire, that provides traction for pushing out of the hack and for walking on the ice without slipping.
When players aren’t delivering a stone, they slip a rubber gripper over their slider shoe so both feet have traction. This is especially important for sweeping, where having two firm contact points on the ice allows for harder, safer brushing. The gripper also protects the soft Teflon slider from damage when stepping off the ice between shots.