What is Pebbled curling ice sheet?

Answer 1

Before each curling match, the ice is "pebbled" by spraying drops of hot water on the ice. The drops freeze within a few seconds and make the ice surface bumpy (about 1 bump per every square centimeter of ice). Quality pebble is one of the keys to modern finesse-based curling. It allows the rocks to slide down the ice much more easily and act more consistently than if the ice were simply smooth like a mirror. It also gives particles of debris a place to hide so that they don't run under the rock and cause the rock to do strange things.

Wearing-down of the pebble is an important factor in strategy, as it causes the behavior of the rocks to change as a game goes on. For example, rocks may act differently on the right side vs. left side of the sheet if significantly more rocks have been thrown on one side vs. the other.