The acid test for any April Fool’s gag in the media is whether it manages to convince any other publication to write about it. And on that count, this year’s haul was rather feeble (although the BBC’s “flying penguins” video was at least very well done). In fact, with the exception of my colleague Tom Chatfield’s erudite post below on the origins of the practice, which has ensnared one commenter so far, the only April Fool I’ve come across that has evidently fooled anyone is this gem at ChessBase.com. The website claimed yesterday to have received copies of the letters sent by the late Bobby Fischer during his long period of self-imposed exile to other chess luminaries (and although I’ve given the game away, it’s definitely worth a look). Thanks to the usually highly authoritative Marginal Revolution, which this morning directed me to the Fischer article before hastily withdrawing its recommendation.