Switchback

The Switchback is a concept introduced in Season 15, in which teams encounter a task from a previous season that was markedly difficult.

Switchback tasks

 * In Season 15, a remake of the Roadblock was encountered by teams during the Season 6 stop in Stockholm where in that season, they had to search for their next clue, of which there were 20, hidden within 270 bales of hay; sisters Lena & Kristy spent over 10 hours searching for the clue before Phil came to them in the field to tell them that everyone else had already checked-in and they were eliminated. The Switchback version had teams searching for one of seven flags within only 186 bales of hay.
 * In Season 20, a Fast Forward in India initially offered in Season 5, but later followed through Season 7, involved shaving off all of the hair from the racers' heads. Married couple Uchenna & Joyce (Although Uchenna was already bald) took the Fast Forward in Season 7, ultimately giving them an advantage and the lead that carried onto the end with their victory. In Season 20, friends Bopper & Mark (Bopper was also already bald) took the Switchback Fast Forward, but ended up in last place during that leg and got eliminated due to being to far behind.