five-tenths after the other), and with the track clocks running and scoreboards displaying time. At the end of the session, the show officials then determine the most competitive field (not necessarily the fastest) by finding a grouping of cars whose race time are very close together. Those cars are asked to return to the strip for an additional timed run to ensure there is no sandbagging. In the first few seasons, the clock displays were turned off so that only Pinks officials know the elapsed time of the cars. The Christmas tree is turned off, and either Rich or Kail Christensen start the run with the show's signature arm-drop start. Sixteen cars (but more often 32 in recent years although there was a 64-car field once), known as the "All Out 16", are then chosen by the producers to compete in the main portion of the competition. The cars are not formally bracketed, so the producers and technical officials may determine the race by car types (often by the classic GM-Ford, Ford-FCA, or GM-FCA rivalries, or brand nationality), driver types (sometimes past Pinks grudges, family members, or region), or any manner which they may choose (closest in elapsed time). However the competition is generally limited to what the technical advisors (most of them racers) decide is the "most competitive" field. In many cases they will attempt to come up with something interesting to further qualify the field, for example a slower class being allowed to earn a spot in the final 16, but in every case the idea is to find a full class of at least 16 cars in which each car is running within a tenth to 2 tenths of a second of each other. Starting in Season 3, the rules of the arm-drop qualifying pass were changed following evaluations. Cars are now paired by their elapsed time, with officials determining a "floating minimum" time that will be posted as the cars are staging. The cars must run faster than the posted time on the display near the starter to continue being considered. This again assists in weeding out sandbagging. In all cases, the idea is to once again weed out teams that use the delay box, since the Pro Tree would throw off Sportsman racers whose reaction times are based on using a delay box (.500 or 1.000 seconds delay from throttle to launch), and the arm