How Do You Become A "Top Contributor"?

To gain a Top Contributor badge on Yahoo Answers, you must answer a lot of questions in a particular category and get best answers in there as well. You must have a certain percent of best answer but Yahoo has kept this a secret. Once you get your TC badge, you must keep answering questions in your TC category or you will lose the badge. You can be a TC in up to 3 categories. Thee are also no TC awarded in the Jokes & Riddles and the Polls & Surveys categories.