166ccb49_ranite_Curling_Club_of_Seattle__What_It_Means
[Term] FREE GUARD ZONE [What It Means] 
This rule states that none of the first four rocks thrown in an end can remove an opponents rock from play if it is in front of the house. This rule was imposed to increase the strategy aspect of the game. The four rock free guard zone rule is used in America, while the Canadians usually play the three rock free guard zone.
Glossary | Granite Curling Club of Seattle
What It Means