B&R 101
On a fraction rig the forestay doesn't go all the way to the masthead. (Otherwise, it would be called a "headstay.") Fraction rigs are often described by the percentage of foresail area compared to how they would be if masthead rigged. For example, some are 7/8ths rigs, while others are 3/4ths rigs. On a fraction rig design, the primary power comes from the mainsail, and the jib is used more to balance the rig and help point higher by directing airflow over the main. Consequently, fraction rigs seldom employ overlapping sails (genoas). A masthead rig depends more on the foresail for power, so genoas up to 150% of J are used. A B&R rig eliminates the need for backstays by sweeping the spreaders aft. Some B&R boats are masthead rigged (e.g. the H460) while others are fraction rigged (H410). Fraction B&R rigs tend to have enormous spreaders with outboard stays that lead directly to the chainplates. This simplifies the building process since only one set of chainplates is needed. It also eliminates any possibility of using a genoa since the fairleads would have to be so far outboard that the boat wouldn't point on a true close reach. The advantages of such a rig are: the ability to carry a larger roach; the elimination of the need for running backstays; and not having to have gorillas on the crew to grind in the genoas on every tack. The disadvantage is that the main stalls when running because it can only be let out so far before the sail hits the spreaders.