 <unk> jumps ( long jump and triple jump ) and all throws must be initiated behind a line . In the case of horizontal jumps , that line is a straight line perpendicular to the runway . In the case of throws , that line is an arc or a circle . Crossing the line while initiating the attempt <unk> the attempt — it becomes a foul . All landings must occur in a sector . For the jumps , that is a sand filled pit , for throws it is a defined sector . A throw landing on the line on the edge of sector is a foul ( the inside edge of the line is the outside edge of the sector ) . Assuming a proper attempt , officials measure the distance from the closest landing point back to the line . The measuring tape is carefully <unk> to the shortest distance between the point and the line . To accomplish this , the tape must be perfectly perpendicular to the take off line in jumps , or is pulled through the center point of the arc for throws . The officials at the landing end of the tape have the zero , while the officials at the point of initiation measure and record the length . Whenever a record ( or potential record ) occurs , that measurement is taken ( again ) with a steel tape , and observed by at least three officials ( plus usually the meet referee ) . Steel tapes are easily bent and damaged , so are not used to measure everyday competitions . For major competitions , each competitor gets three tries . The top competitors ( usually 8 or 9 depending on that competition 's rules or the number of lanes on the track ) gets three more tries . At that level of competition , the order of competitors for those final three attempts are set — so the competitor in first place at the end of the third round is last , while the last competitor to qualify goes first . Some meets <unk> the competition order again for the final round , so the final attempt is taken by the leader at that point . At other competitions , meet management may choose to limit all competitors to four or three attempts . Whatever the format , all competitors get an equal number of attempts . 
