False start In sports , a false start is a movement by a participant before ( or in some cases after ) being signaled or otherwise permitted by the rules to start . Depending on the sport and the event , a false start can result in immediate disqualification of the athlete from further competition , a warning in which a subsequent false start would result in disqualification , or a penalty against the athlete ' s or team ' s field position . False starts are common in racing sports ( such as swimming , track , sprinting , and motor sports ) , where differences are made by fractions of a second that often cannot be comprehended by the human mind , and where anxiety to get the best start plays a role in the athletes ' behavior . False starts are signalled by firing the starting gun twice . A race that is started cleanly , on the contrary , is referred to as a " fair start " or " clean start " . In sports . American and Canadian football . In American football and Canadian football , a false start is movement by an offensive player ( other than the center ) after he has taken a set position . For offensive linemen , this movement might be as minimal as a couple of centimeters , although the rule ' s intent is to prevent offensive players from unfairly drawing the defense offside . A false start brings a penalty of five yards . Unlike an offsides penalty , the play becomes a dead ball immediately after a false start has been committed while with an offsides penalty , the play is run as usual . This is done to prevent a defensive player reacting to a false start from hitting the quarterback while going through the snap count , which would make the quarterback more susceptible to injury . At the end of the 2005 NFL season , owners complained regarding false start penalties on players whose flinches have little effect upon the start of the play , such as wide receivers . In response , the NFL competition committee has said that they plan to inflict fewer false start penalties on players who line up behind the line of scrimmage . Athletics ( track and field ) . In track and field sprint s , the sport ' s governing body , the IAAF , has a rule that if the athlete moves within 0 . 10 seconds after the gun has fired the athlete has false started . This figure is based on tests that show the human brain cannot hear and process the information from the start sound in under 0 . 10 seconds . This rule is only applied at high - level meets where fully automated force or motion sensor devices are built into the starting blocks that are tied via computer with the starter ' s gun . In the vast majority of lower - level meets , false starts are determined visually by the officials . From 2003 , IAAF rules stated that after any false start committed , all athletes were to be warned . Any subsequent false start by any athlete , or athletes , led to immediate disqualification of that latter athlete . Previously , disqualification occurred only after the same athlete false - started twice . An analysis of start times by sprinters at the 2008 Beijing Olympics demonstrated that male and female sprinters can achieve reaction times of 109 and 121 ms in one out of 1 , 000 starts . The same analysis showed fewer false starts among the women and it suggests that the apparent sex difference is caused by the use of the same starting block force threshold for males and females . The authors calculated that were the force threshold to be reduced by 22 % for females , to take into account their lower rate of developing muscle strength , then males and females would exhibit similar reaction times and numbers of false starts . In August 2009 the IAAF announced that from January 2010 , a zero - tolerance stance to false - starts would be adopted . Athletes false starting are now immediately disqualified . The following year the rule led to prominent disqualifications at the 2011 World Championships in Athletics : world record holder Usain Bolt was disqualified from the 100 m final and 2008 Olympic champion Christine Ohuruogu suffered a similar fate in the 400 m heats . Horse racing . In thoroughbred horse racing , a false start occurs when a horse breaks through the starting gates before they open . There is usually no penalty ; the horse is simply reloaded into the gate . In some events , a horse who breaks through the starting gates is disqualified . A notable example was the 2006 Preakness Stakes when Kentucky Derby winner Barbaro broke through the gate early ; he was reloaded and the race was started properly . The 1993 Grand National was void because the recall flag to signal a false start was not unfurled , so that most jockeys continued to race . Ice hockey . In ice hockey , a false start occurs when a team commits a faceoff violation . When this occurs , the player taking the face - off from the offending team is replaced by a teammate . A second faceoff violation by the same team results in a minor penalty . Sailing . In sailing , the race committee decides at the preparatory signal ( usually 4 minutes before the start ) what the rules on false starting will be by display the P , I , Z or Black Flags . A P Flag means any boat on the course side ( OCS ) of the start line at the starting signal must return , clear the start line and then restart . The I Flag means a boat which is OCS must round either end of the start line by coming back to the pre - start side and then restarting ( the ' round the ends ' rule ) . The Z Flag means a boat which is OCS in the minute leading up to the start or at the start itself is given a 20 % scoring penalty . The Black Flag means a boat which is OCS in the minute leading up to the start or at the start itself is disqualified . Failing to return to start correctly under the P or I Flag rules means the boat is scored O . C . S and receives points equivalent to disqualification . Swimming . In swimming , any swimmer who starts before the starting signal is given an automatic disqualification . A notable example during the 2008 Olympics occurred when Jiaying Pang was disqualified due to a false start . This allowed Libby Trickett to advance to the final round , in which she won a silver medal . At the 2012 London Olympics , Chinese swimmer Sun Yang jumped into the water too early in the 1500m final , but was not judged to have false started as the starter had aborted the initial start due to crowd noise , causing Yang to fall into the pool . Yang went on to win the race and the gold medal , setting a new world record . A similar incident occurred in the women ' s 100m breaststroke final . In entertainment . In a live musical performance , a false start is an intro to a song that is quickly cut short to begin another song . One famous example is Elvis Costello playing " Radio Radio " on a television broadcast of " Saturday Night Live " . False starts , mistakes , or imitations of such , are occasionally included by musicians on finalised albums . The Beatles ' songs " Dig a Pony " and the North American version of " I ' m Looking Through You " include them . Electric Light Orchestra ' s " Rockaria ! " , Green Day ' s " Good Riddance ( Time of Your Life ) " , " Old Time Rock and Roll " by Bob Seger , " Tangerine " by Led Zeppelin , Monkees song " Magnolia Simms " , and James Blunt song " You ' re Beautiful " are other examples . In a YouTube episode of " Minutes with Murray " , Murray Cook played two false starts on the Maton electric guitar while playing " Eagle Rock " . False starts are even used for sign languages by deaf people and their interpreters ' speeches . For example in a 1987 videotape called " Sign Me a Story " , Linda Bove ( from Sesame Street ) introduces herself but realizing that she ' s deaf , she needs help from interpreter / voice - over Elaine Bromka and tells her that maybe some people didn ' t understand what she just said and Elaine says " Why don ' t we start again ? " [ ]