Ysplix

During Olympic Games (and not only) in Classic Greece, they used to use a special mechanism to control the simultaneous starting of race horses, or racers. This mechanism, already used in 344 BC, was a system, positioned to the race start point, in front of racers, to avoid early starts. It consisted of vertical wooden pales and twisted animal nerves. The mechanism was called Ysplix.

Sources from Greek language:
*http://www.tovima.gr/print_article.php?e=B&f=12386&m=B02&aa=2
*http://www.enet.gr/online/online_print?id=71032708
*http://www.mythologia.8m.com/ptisi.html