Maybe Poe was right after all. It isn’t that hard to write a tale of ratiocination, or a detective story if you like best. All it takes is a mystery, a solution and a detective to work it out, author fiat being near absolute. So why do so many detective stories fall flat on their faces, whereas a few get called masterpieces? That’s because writing a detective story may be easy but to write a good one is much more difficult. You need to be a good writer to start with – no matter what some people say or claim, the envelope matters as much as the content and bad writing can irremediably spoil an otherwise technically perfect story. You also need to be a good plotter and this is where things get complicated, for what is a good plot exactly? On the surface it looks as a rather silly question, but it isn’t.
A good plot is about two things, one of which only is absolutely necessary: cohesion and surprise. The latter is often taken as the ultimate criterion for good mystery writing, but as Alfred Hitchcock pointed out it is actually the easiest one to achieve; the many and many often inferior reiterations of the Roger Ackroyd trick over the years testify to this. You don’t need being a genius to write a story that ends with a juggernaut twist (« The narrator was an alien from planet Zyndu. Ha ha, got you suckers. ») What takes genius on the other hand is making said twist organic to what came before, so that the reader realizes the writer didn’t pull it out of thin air; the twist was there from the beginning and careful reading would have allowed them to anticipate it. This is where cohesion comes in. A good plot is not just one that fools and surprises though ideally it does it too – it is one in which everything makes sense.
Think it’s a basic requirement? It was actually a long time in the making and one of the reasons why decalogues and commandments were written, with « fair play » becoming the one cardinal virtue of the genre. Early mystery writers didn’t bother with such trifles. Their detectives were omniscient, which meant they could see things nobody else saw, and used either arcane knowledge or hidden clues (« The detective picked up something on the carpet then put it in his pocket. ») This is not a criticism – just the way they did things back then and no one complained. That’s why people complaining that most of the Sherlock Holmes stories are bloody messes plotwise miss the point entirely: they were aimed at an audience that didnt (and still doesn’t) care for subtlety in plotting but instead wanted a jolly good yarn that would leave them starry-eyed at the Great Detective’s prowess . The Victorian era was very much the genre’s Punch and Judy period.
Fair play as we know it was largely an Edwardian invention even though not theorized at the time. Detective story writers realized that their stories would make an even bigger splash with readers if their detectives relied on the clues at hand rather than « things they picked up on the carpet ». The detective story as « mere puzzle » was not yet there but the idea that it must be sound slowly gained traction in the years before WW1 and became mainstream in the Twenties. Genuinely or seemingly foolproof plotting became the gold standard and more or less remains so to this day – a mystery writer needs to be otherwise incredibly talented to get away with loose plotting.
The problem being of course that not all writers and readers agree on what « loose plotting » means. To some – let’s call them « the logicians » – a bad plot is one with major plot holes, whereas to others – let’s call them « the pyrotechnicians »- it is one that fails to surprise. I tend to side with the former over the latter for the reasons I stated above but also because a foreseeable plot is by definition one that allows one to see through, which is what any fair mystery should be about. Don’t get me wrong: I like to have the rug pulled from under my feet as much as everyone else; what I don’t like is being taken for a fool. The « fair play » requirement is ultimately deontological as much as it is aesthetical. Giving all the clues to the reader is not just a matter of logic or sportsmanship – it is a matter of respect.