 Horizontal 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 invalidates 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 straightened 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 rearrange 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 . 
 Horizontal <a href='uninflect' title='1'><mark>jumps</mark></a> ( long jump and triple jump ) and all throws must be initiated behind a line . In the case of horizontal jumps , that line <a href='drop_aux' title='2'><mark>is</mark></a>a straight line perpendicular to the runway . In the case of throws , that line <a href='drop_aux' title='3'><mark>is</mark></a>an arc or a circle . Crossing the line while initiating the attempt <a href='uninflect' title='4'><mark>invalidates</mark></a> the attempt — it <a href='uninflect' title='5'><mark>becomes</mark></a> 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 <a href='drop_aux' title='6'><mark>is</mark></a>a foul ( the inside edge of the line <a href='drop_aux' title='7'><mark>is</mark></a>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 straightened 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 <a href='got' title='8'><mark>have</mark></a> the zero , while the officials at the point of initiation measure and record the length . Whenever a record ( or potential record ) <a href='uninflect' title='9'><mark>occurs</mark></a> , that measurement is taken ( again ) with a steel tape , and observed by at least three officials ( plus usually the meet referee ) . Steel tapes <a href='drop_aux' title='10'><mark>are</mark></a>easily bent and damaged , so <a href='negative_concord' title='11'><mark>are</mark></a> <a href='negative_concord' title='12'><mark>not</mark></a>used to measure everyday competitions . For major competitions , each competitor <a href='uninflect' title='13'><mark>gets</mark></a> three tries . The top competitors ( usually 8 or 9 depending on that competition <a href='null_genetive' title='14'><mark>'s</mark></a>rules or the number of lanes on the track ) <a href='uninflect' title='15'><mark>gets</mark></a> 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 <a href='drop_aux' title='16'><mark>is</mark></a>last , while the last competitor to qualify <a href='uninflect' title='17'><mark>goes</mark></a> first . Some meets rearrange 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 . 
Horizontal jump ( long jump and triple jump ) and alll throws must be initiated behind a line . In the case of horizontal jumps , that line a straight line perpendicular to the runway . In da case of throws , dat line an arc or a circle . Crossing the line while initiating the attempt invalidate the attempt — it become a foul .allll landings must occur in a sector . For tdajumps , that is a sand filled pit , for throws it is a defined sector . A throw landing on the line on the edge of sector a foul ( the inside edge of the line thdautside edge of the sector ) . Assuming a proper attempt , officials measure thedastance from the closest landing point back to the dae . The measuring tape is carefully straightened to the sdatest distance between the point and the line . To accomplish this , the tadamust 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 got the zero , while the offdaals at the point of initiation measure and record the lengda. Whenever a record ( or potential record ) occur , that measurement is taken ( again ) with a steel tape , and observed by at least three officials ( plus usually the meet referee ) . Steel tapes easily bent and damaged , so ain't used to measure everyday competitions . fa major competitions , each competitor get three tries . The top cdaetitors ( usually 8 or 9 depending on tdatcompetition  rules or the number of lanes on the track ) get three more tries . At that level of competition , the order of competitors for those final three attempts r set — soo the competitor in first place at the end ofdae third round last , while the last competitor to qualify go first . Some meets rearrange the competition order again for the final round , so the final attempt is taken by the leader dathat point . At other competitions , meet management may claim to limit all competitors to four or three attempts . w.e the format adall competitors get an equal number of attempts .