to improve safety, most recently in 2004 from 40°. The current throwing sector angle (34.92°) was chosen because it provides a sector whose bounds are easy to measure and lay out on a field (10 metres out from the center of the ring, 6 metres across). The athlete must leave the throwing circle from the back half. Foul throws occur when an athlete: Does not pause within the circle before beginning the putting motion. Does not complete the putting movement initiated within thirty seconds of having their name called. Allows the shot to drop below his shoulder or outside the vertical plane of his shoulder during the put. At any time if the shot loses contact with the neck then it is technically an illegal put. During the putting motion, touches with any part of the body (including shoes): the top or ends of the toe board the top of the iron ring anywhere outside the circle. Puts a shot which either falls outside the throwing sector or touches a sector line on the initial impact. Leaves the circle before the shot has landed. Does not leave from the rear half of the circle. Regulation misconceptions The following are either obsolete or non-existent, but commonly believed rules within professional competition: The athlete must enter the circle from the back (none of the rule books contain such a clause). The athlete entering the circle, then exiting and re-entering it prior to starting the throw results in a foul (all the rule books allow an athlete to leave a circle prior to starting a throw, but this still counts within the 30 second time limit; the allowable method of exiting the circle varies by rule book). Loose clothing, shoelaces, or long hair touching outside the circle during a throw, or an athlete bringing a towel into the circle and then throwing it out prior to the put, results in a foul. Competition Shot put competitions have been held at the modern Summer Olympic Games since their inception in 1896, and it is also included as an event in the World Athletics Championships. Each of these competitions in the modern era have a set number of rounds of throws. Typically there are three qualification rounds to determine qualification for the final. There are then three preliminary rounds in the final with the top eight competitors receiving a further three throws. Each competitor in