The mixed or open doubles format is unique to the sport of curling and there are several key areas where it deviates from the traditional game.
- Two rocks are placed prior to the start of each end
- Each team has only two players. In Mixed Doubles league (Thursday evening,) one must be a male and one must be a female. Sunday's Open Doubles league does not have that requirement.
- Each team throws only five rocks (instead of eight)
- The person that throws the first rock in any end must also throw the last rock in the same end
- The person that throws the second stone must also throw the third and fourth stone in the same end
- The order of throwing may change with every end, but may not change within the end
- No rocks, including any of the same color, may be removed (taken out) by any player until the fourth stone is thrown
Who has Hammer?
What's known as the hammer or the last rock advantage is normally decided by coin toss for the first end in a game of curling and is given to the team that didn't score at the end of a typical end. In the mixed doubles game, having the hammer is a choice. The team that won the coin toss prior to the game or the team that did not score in the previous end is given a choice--take hammer or give the hammer to the opponent.
Starting an End: Placed Stones
In this game, two stones are in place prior to the start of an end. The team with the hammer has stone in the house (circles) just behind the T-line. The other team has a stone along the center line above the house. There are hash marks on the ice to help locate the rocks. Before the game the officials inform the athletes of which hash mark to use. Each team has an option of one power play per game when they have last rock where the starting rocks are placed off to the side instead of on the center line.
It's a Draw Game
The rules prevent any rocks - including a team's own rocks - from being removed prior to the fourth thrown stone in an end. This forces the athletes to crowd rocks into the house around the button (center of the rings). If any stone prior to the fourth stone removes a rock, teams reposition the rocks in their original location remove the shot stone from play. You might see people manually moving rocks in the house (either kicking them or pushing them with their broom) during this process. When the fourth rock is to be thrown, any of the stones may be removed without penalty.
Where are the Sweepers?
As each team has only two players, the traditional sweepers are not present. Some teams may choose not to sweep their rocks while others may choose to have the thrower sweep their own rock. The non-throwing player can choose to sweep the rock or stand in the house to hold the broom.
As always, the team with the rock (or rocks) closest to the button earns the points. A point is counted for every rock closer than an opponent's closest rock. There are no eight enders in this game, but a team may still accomplish a perfect end if they score six points.