spreads, and double and triple combinations, usually with many turns and changes of direction. The intent is to jump cleanly over a set course within an allotted time. Time faults are assessed for exceeding the time allowance. Jumping faults are incurred for knockdowns and blatant disobedience, such as refusals (when the horse stops before a fence or the horse, "runs out") (see "Modern rules" below). Horses are allowed a limited number of refusals before being disqualified. A refusal may lead to a rider exceeding the time allowed on course. Placings are based on the lowest number of points or "faults" accumulated. A horse and rider who have not accumulated any jumping faults or penalty points are said to have scored a "clear round". Tied entries usually have a jump-off over a raised and shortened course, and the course is timed; if entries are tied for faults accumulated in the jump-off, the fastest time wins. In most competitions, riders are allowed to walk the initial course but not the jump-off course (usually the same course with missing jumps, e.g., 1, 3, 5, 7, 8 instead of 1, 2, 3, 4, 5, 6, 7, 8, 9 or the same course but timed) before competition to plan their ride. Walking the course before the event is a chance for the rider to walk the lines he or she will have to ride, in order to decide how many strides the horse will need to take between each jump and from which angle. Going off course will cost time if minor errors are made and major departures will result in disqualification. The higher levels of competition, such as "A" or "AA" rated shows in the United States, or the international "Grand Prix" circuit, present more technical and complex courses. Not only is the height and width ("spread") of an obstacle increased to present a greater challenge, technical difficulty also increases with tighter turns and shorter or unusual distances between fences. Horses sometimes also have to jump fences from an angle rather than straight on. For example, a course designer might set up a line so that there are six and a half strides (the standard measure for a canter stride is twelve feet) between the jumps, requiring the rider to adjust the horse's stride dramatically in order to make the distance. This could also mean that the rider may have to add or subtract