Forcado

Forcado, By Katxi

Something I saw on this very website put me in mind of a question that I and many others will have asked from time to time:
Why is it that you see a number of runners wearing funny green hats in the encierro? It seems like a joke, but it is quite the opposite.
But why should I explain it. Just go to www.wikipedia.org and type in the word “Forcado” and all will be revealed.