'Conned again Watson!'

review by 
Helen Joyce
March 2003

Conned Again Watson! Cautionary tales of logic, maths and probability

Not many books about maths have chapters that start "The dead man seemed to stare at me in a most disconcerting way." But maybe more should - this book is a highly entertaining read, crossing sound mathematical exposition with the classic Sherlock Holmes style of investigation.

The writing is really remarkably clever - the tone of the original Sherlock Holmes mysteries is reproduced with almost uncanny accuracy. Watson is satisfactorily stupid, and there is a lot of fun to be had with historical hindsight - Holmes invests in the newly invented Monopoly boardgame, Waton ridicules the notion of heavier-than-air flight, and so on.

Most of the book is about probability, and it would make a useful accompaniment to a first probability course - the amount of material covered is quite surprising. But it should be equally attractive to the reader with no special mathematics background - all the explanations are clear and comprehensible. A useful afterword gives further reading and explains the basics behind each chapter.

The method of the infallibly stupid narrator, used by Conan Doyle to add mystery and delay the denouement, is here used with great effect, as Watson walks into every conceivable logical error, and sets things up perfectly for Holmes' explanations. Perhaps writers of mathematics textbooks should take note - it is a lot of fun to follow an argument presented by an all-knowing guide, in the company of someone reliably dense who ensures that, no matter how many mistakes you make, you cannot be bottom of the class!

Book details:
Conned Again Watson!: Cautionary tales of logic, maths and probability
Colin Bruce
paperback - 299 pages (2002)
ISBN: 0099428571