Why are the Olympic Games held every four years?

But why were the ancient Olympics held every four years?

I am not a number., The Greeks had four major sports festivals (Olympic, Pythian, Nemean, and Isthmian games). They were spread out over a 4-year cycle, to give athletes an opportunity to compete in all of them.

baymax, it's nothing to do with belief. Heracles is Greek, Hercules is Roman.

I love the age old tradition of lighting the torch from the sun in Athens which then goes on its trek around the world.

otherwise known as Hercules, or Heracles... depending on what you believe?