Square being relative to what?? your body or the line, if it is the line you would have to close the club face on the backswing(in relation to your body) and open it through impact for it to be square to the line. Watch the first minute of this video, I am assuming the first example(first two putts) is the arc and the second example is the SBST [YOUTUBE]1TDSWxBHVOY[/YOUTUBE]