Peter, I ran the lines (braces) back to the mizzen head because that's about the height of the yardarm. Thus when I adjust the braces, I am swivelling the yard, but it stays in a horizontal plane. If the braces ran down to the deck, pulling on one would skew the yard, one end up and one end down. To counteract this, lifts are required -- these are standing lines that go from the yardarm ends up to the mast head.
I had no need to rig lifts since I had the mizzen mast at the right height, thus 2 lines and some complexity were saved.