The putterhead will swing on an arc but the shaft will swing directly along or parallel to the target line. The same thing in a full swing, the head will swing up and around but one end of the shaft will always point to the target line or be parallel to it in an on plane swing.
The putterhead will swing on an arc but the shaft will swing directly along or parallel to the target line. The same thing in a full swing, the head will swing up and around but one end of the shaft will always point to the target line or be parallel to it in an on plane swing.