Computers are already fighting our wars for us, managing our economy, taking away our jobs and beating us at chess. Now, to cap it all, it seems they are presuming to advise us on how to write novels as well. Or, at least, bestselling novels. This ought to be annoying, but I have to admit that the results of computer surveys into what makes a bestseller are actually of compelling interest and full of the sorts of facts and stats that some of us really enjoy. Did you know, for instance, that there is a specific BISAC code for ‘historical romance novels with Vikings’?

Jodie Archer is a former publisher and literary consultant and Matthew Jockers is a co-founder of Stanford University’s Literary Lab. The value of the kinds of programs he has worked on has already been proved. By close verbal and textual analysis, ‘stylometrics’ and pattern recognition, it is fairly