Mixed curling the house. In the 2015-16 season, a new rule called "power play" was added, which each team can exercise in one end per game, only when they have the hammer. Instead of positioning the rock in the house on the center line, it is placed to a position straddling the edge of the eight-foot circle, with the back edge of the stone touching the tee line. The opponent's guard stone is placed in line with the stone in the house and the hack. The power play cannot be used in an extra end. Mixed curling Mixed curling, also known as
Curling exclusive rights to the Ailsa Craig granite, granted by the Marquess of Ailsa, whose family has owned the island since 1560. According to the 1881 Census, Andrew Kay employed 30 people in his curling stone factory in Mauchline. The last harvest of Ailsa Craig granite by Kays took place in 2013, after a hiatus of 11 years; 2,000 tons were harvested, sufficient to fill anticipated orders through at least 2020. Kays have been involved in providing curling stones for the Winter Olympics since Chamonix in 1924 and has been the exclusive manufacturer of curling stones for the Olympics since the