The slippery science behind curling starts with the ice itself. Curling ice must be perfectly flat – far flatter than a typical ice hockey rink – and is sprayed with droplets of water before each game to produce a pebbled surface.

So, why all the shouting? Don't confuse it with trash talk. With the “sheet” – i.e., playing area – measuring up to 150 feet long, yelling is the best way for the skip (team captain) to communicate how the sweepers should work to move the stone down the ice as they take each shot.

Curlers sweep the ice to help the stone travel farther and straighter. Sweeping in front of the stone reduces friction and helps the curlers control the amount of curl the stone undergoes. The sweeping quickly heats and melts the pebbles on the ice leaving a film of water.