Sometimes being random can be an advantage. When you are playing a game against an opponent who is trying to guess your strategy, having the ability to use randomization to be unguessable is critical. In hunting, the caribou are trying to guess the strategy of the hunters to elude them. From The Secret of Our Success by anthropologist Joseph Heinreich:
"Traditionally, Naskapi hunters decided where to go to hunt using divination and believed that the shoulder bones of caribou could point the way to success. To start the ritual, the shoulder blade was heated over hot coals in a way that caused patterns of cracks and burnt spots to form. This patterning was then read as a kind of map, which was held in a pre-specified orientation. The cracking patterns were (probably) essentially random from the point of view of hunting locations, since the outcomes depended on myriad details about the bone, fire, ambient temperature, and heating process. Thus, these divination rituals may have provided a crude randomizing device that helped hunters avoid their own decision-making biases."
(Thanks for the book review, Scott Alexander)
