original: chess boxing fights have been organized since early 2003 .
simplifications: chess boxing fights have been put into order since early 2003 chess boxing fights have been going on since 2003 . chess boxing fights have been organized since early 2003 . chess matches have been organized since early 2003 . chess box fights have been around since early 2003 . chess boxing fights have been organized since early 2003 . chess boxing fights started in 2003 . chess boxing fights have been conducted since early 2003 .