How did they decide on which kid to sacrifice?
No one was chosen at random, like in the Hunger Games. Locals were choosing the sacrificial youngster precisely. Childish purity enabled the chosen one to be either male or female.
It was necessary to pick youngsters from reputable homes between the ages of 6 and 8. There has to be a perfect kid offered up to the gods. Otherwise, they thought the Inca people would be punished, whether via a terrible harvest season or anything else.