<P> Traditionally, the 4 × 400 m relay finals are the last event of a track meet, and is often met with a very enthusiastic crowd, especially if the last leg is a close race . It is hard to measure exact splits in a 4 × 400 (or a 4 × 100) relay . For example, if a team ran a 3 - minute 4 × 400, it does not mean every runner on the team has to run a 45 - second open 400, because a person starts accelerating before he / she has the baton, therefore allowing for slightly slower overall open 400 times . A 4 × 400 relay generally starts in lanes for the first leg, including the handoff . The second leg then proceeds to run in lanes for the first 100 metres, after which point the runners are allowed to break into the first lane on the backstretch, as long as they do not interfere with other runners . A race organizer then puts the third leg runners into a line depending on the order in which they are running (with the first place closest to the inside). The faster teams pass first, while the slower teams have to slide in to the inside lanes as they come available . </P> <P> Each runner must hand off the baton to the next runner within a certain zone, usually marked by triangles on the track . In sprint relays, runners typically use a "blind handoff", where the second runner stands on a spot predetermined in practice and starts running when the first runner hits a visual mark on the track (usually a smaller triangle). The second runner opens their hand behind them after a few strides, by which time the first runner should be caught up and able to hand off the baton . Usually a runner will give an auditory signal, such as "Stick!" repeated several times, for the recipient of the baton to put out his hand . In middle - distance relays or longer, runners begin by jogging while looking back at the incoming runner and holding out a hand for the baton . </P> <P> A team may be disqualified from a relay for: </P> <Ul> <Li> Losing the baton (dropping the baton) </Li> <Li> Making an improper baton pass, especially when not passing in the exchange zone </Li> <Li> False starting (usually once but sometimes twice) </Li> <Li> Improperly overtaking another competitor </Li> <Li> Preventing another competitor from passing </Li> <Li> Wilfully impeding, improperly crossing the course, or in any other way interfering with another competitor </Li> </Ul>

How many types of track events do we have