 This changed the starting strategy of the game as the team with the hammer was able to throw up two guards uncontested instead of the usual 1 allowed with the previously used 4 rock rule.Through the addition of the Grand Slam events and the new rule changes, the WCT is rapidly becoming a well known series to sports fans worldwide.On June 28, 2017, the Canadian based World Curling Tour officially merged with the European and Asian based Curling Champions Tour to create a worldwide entity focused on growing the game on the international stage.