The idea of a fictional series having a "canon" was first used by fans of Sir Arthur Conan Doyle's Sherlock Holmes series, who for nearly a century have played what they call the "Great Game": pretending that Holmes' adventures were actual events, recorded by Dr. Watson, with Conan Doyle acting as their literary agent. Sherlockians playing the "Great Game" use evidence from Conan Doyle's stories to deduce unrecorded details about Holmes' and Watson's lives. To do this, they needed rules for the game, and one of those rules was that only stories by Conan Doyle "count". Sherlock Holmes pastiches and tributes by other authors are legion, so the Sherlockians took a page from Biblical criticism and declared that the 56 stories and four novels by Conan Doyle constituted the Sherlock Holmes canon