I wonder whether you are referring to "throw your cap (or hat) into the ring". There was a time when nearly all men wore headgear of one sort or another...flat cap, bowler hat or whatever. As recently as the 1950s there was an advert that claimed: "If you want to get ahead, get a hat!" Many �hat' sayings are based on the fact that hats were virtually universal. When someone decides to become a political candidate, for example, it may be said that he has decided to "throw his hat into the ring". This dates back to the days of prize-fighting, fairground boxing challenges and so on. Men who wanted to challenge the current champion, after he had defeated someone else, would literally throw their caps/hats into the ring. He would select one and the owner of it then came forward to mount his challenge. Being hatless, the crowd easily spotted him moving towards the ring and cleared a path for him.