<P> In mixed doubles curling, two players, one woman and one man, compose each team . The idea was developed by Curling Canada's Warren Hansen in 2001 to be one of four discipline variations for the introduction of the Continental Cup of Curling . </P> <P> The first World Mixed Doubles Championship took place in 2008 . Since its inception, Switzerland has won six of the first ten titles . Russia and Hungary have won their first world curling titles in the mixed doubles championship, and New Zealand, France, Austria, and the Czech Republic won their first world curling medals . </P> <P> The IOC did not approve the events for inclusion into the 2010 Winter Olympics, but an attempt to include the mixed doubles in the following winter Olympiad succeeded, making its Olympic debut at the 2018 Winter Olympics . </P> <P> At the start of each end, two rocks start in play--one in the back 4 foot with the front of the rock at the very center of the house, and a rock of the opposite color guarding on the center line, halfway between the front of the house and the hog line . Five rocks are played per team, with scoring performed as normal . One thrower must throw the first and last stones of each end, while the other thrower must throw the three in between . </P>

When did mixed curling become an olympic sport