Gaff rig is a sailing rig (configuration of sails, mast and stays) in which the sail is four-cornered, fore-and-aft rigged, controlled at its peak and, usually, its entire head by a spar (pole) called the gaff. Because the size and shape of the sail, a gaff rig will have running backstays rather than permanent backstays. The gaff enables a fore and aft sail to be four sided, rather than triangular. A gaff rig typically carries 25 percent more sail than an equivalent bermudian rig for a given hull design.