I'll be honest here – I don't really know why Sudoku has taken off to the extent it has. You can't walk into a bookshop on the high street (and certainly not the airport) without tripping over stands of the latest compendia of Sudoku and its multifarious variants. The ubiquitous Carol Vorderman has become the Sudoku poster-girl, although quite why that should be escapes me also, unless the intellectual reputation of the TV show “Countdown” is more extensive than I had thought. Whatever the underlying explanation, this puzzle fad certainly seems to have grown into quite a phenomenon.
The first sighting of this puzzle appears to have been in the pages of the magazine Scientific American many years ago. The “Number in Place” puzzle, as it was then, was re-used in several subsequent publications, before becoming a serious craze in Japan in the 1980s. It entered the British press in the early 2000s, with the Daily Mail and Times running it under its exotic Japanese name (which, I am led to believe, is an abbreviation for Japanese for “Number in place”).
And now, in 2006, the place is coming down with it.
Perhaps it is superfluous to describe the principles of Sudoku, but for the benefit of the uninitiated (non-anaesthetists, in the main), a short explanation is probably in order. Sudoku is a logic puzzle centred around a square grid of 9 cells by 9, which is subdivided into 9 blocks of 3 cells by 3. Each cell contains one of the digits 1-9 (but any letter or symbol can be used, as there is no arithmetical relationship between the numbers). The fundamental rule is this: each row, each column, and each 3×3 block must contain only one instance of each digit (or letter or symbol). Each individual puzzle is seeded with some digits already in place, and your role, as the Sudokeur (I made that up) is to put all the other digits back in place, and complete the grid. That's all there is to it – a puzzle of pure unadulterated logic.
The best strategy is usually to start with the digit/letter/symbol which is most frequent in the grid, and systematically work out where its remaining instances should be placed. At one level, it seems very straightforward (as indeed it is), but in the more advanced puzzles, the logical analysis required can be quite intensive. Apparently the first World Sudoku Championships are to be held later in 2006, which suggests to me that there are some people who have far far too much time on their hands.
So how would one go about constructing a Sudoku puzzle to appeal to medics? In “Medical Word Sudoku”, Ayan Panja has woven a classic anagram puzzle into a Sudoku, the tag being that each anagram is a medical word. Of course, for a Sudoku to work, each word must have exactly nine letters, and each of the nine letters must occur only once. An extra clue is that the word itself will occur somewhere (forwards, backwards, up, down) within the Sudoku grid, so once you've solved a few of the cells, and solved the anagram, you can figure out where to place the word, and this will provide extra clues to help you complete the full thing.
I have to say, I was initially rather sceptical. Weaving medical words into such a puzzle struck me as potentially a bit elitist; if nothing else, unless granny was a doctor, she wasn't going to be as much help with solving one of these as she would be with cryptic crosswords. But, despite these preliminary misgivings, Medical Word Sudoku is surprisingly enjoyable and engaging, if you have a moment or two to spare. The puzzles are arranged in four categories, based on difficulty: “Medical Student”, “Junior Doctor”, “Consultant/GP” and “Professor”. I'm sure there is more than a hint of irony behind these classifications, but suffice it to say that the Medical Student ones are pretty easy, and the Professor ones can be fiendishly tricky – especially if you have difficulty solving the anagrams.
Ayan Panja has done a good job in crafting some slippery Sudoku problems, which will keep both afficionados and novices amused. There are some psychologists who recommend Sudoku as a mental exercise to keep the grey cells in trim; maybe we should be recommending this book to our juniors, with the firm instruction that they must progress to “Professor” level before they can complete their specialist training. On the other hand, maybe life is too short for all this, but if you're into puzzles, I think you'll find that this book hits the spot pretty well – and not a Carol Vorderman in sight.