"The most difficult way of reaching the World Cup finals is via the South American group," says Ecuador captain Antonio Valencia. "You can play in Barranquilla in the north of Colombia by the Caribbean Sea, where it's 40 degrees and humid. In La Paz in Bolivia, it's close to 4,000 metres altitude. It takes two or three days to prepare for a game there and then two or three days for your body to recover. It's really difficult and that's from an Ecuadorian who is used to playing at nearly 3,000 metres in Quito."
Over the next week, the national sides of 10 South American countries will play the last two of 18 qualifying matches, bringing to a conclusion a campaign that began in October 2015.