What are the rules of curling?

Curling is often called “chess on ice” for good reason. The Olympic sport blends strategy, physics and teamwork as two teams slide 42-pound granite stones down a 150-foot sheet of ice toward a target called the house — a set of concentric circles with the center known as the button.

Each team has four players: the lead, second, vice-skip and skip. The skip acts as captain and strategist, calling shots and delivering the final stones. A match consists of 10 ends (similar to innings in baseball), with each team throwing eight stones per end.

Only one team scores per end. Points are awarded for every stone closer to the button than the opponent’s nearest stone. A perfect end — all eight stones scoring — is called an “eight-ender,” a rare feat in elite play. If no stones land in the house, it’s a blank end, and the team with the hammer — last stone advantage — keeps it for the next end.

Curling is about more than sliding stones. Players choose from a variety of shots:

· Draw: Stop inside the house for scoring.

· Guard: Block an opponent’s path.

· Takeout: Knock an opponent’s stone out of play.

· Freeze: Nestle against another stone to limit movement.

Sweeping with brooms is critical. It reduces friction, helping stones travel farther and straighter. Teams use sweeping to fine-tune speed and curl, often amid shouts of “Sweep!”

Equipment and Ice Stones are made from rare granite found only in two places: Ailsa Craig in Scotland and the Trefor Quarry in Wales. The ice is “pebbled” — sprayed with water droplets — to create texture that allows stones to curl.

Curling originated in 16th-century Scotland on frozen ponds and made its Olympic debut in 1924 before becoming an official medal sport in 1998. Today, Canada, Sweden and Great Britain dominate the podium. The sport’s nickname, “the roaring game,” comes from the rumble of stones sliding across ice.

Despite its centuries-old roots, curling still puzzles physicists: stones curl in the same direction as their spin, defying typical friction laws. That mystery — along with its mix of finesse and strategy — makes curling one of the most captivating events at the Winter Games.