So it is with mixed feelings that I can report that, brilliant though Pell obviously is (we should also mention that women came second and fourth, and nabbed the under-12 title), the winner of the first Times National Su Doku championship could just as easily have been male. It is true that psychologists have yet to study gender differences in relation to the horribly gripping number puzzle, but those who have compared the intelligence of men and women say that gender is unlikely to be key.

Research done by Paul Irwing, senior lecturer in psychology at Manchester University, shows that men do have higher IQs than women but Irwing doubts that this is relevant to Su Doku. “There is a small sex difference in general cognitive ability, but it shows up only at very high levels in a very small percentage of the population,” he says.

Neil Stewart, lecturer in psychology at Warwick University, points out that men tend to be better at solving spacial problems, women better at verbal tasks. “Su Doku isn’t a spacial test and isn’t verbal, so I think men and women will be equally good at it.”

If gender doesn’t matter, we at least have a partial explanation for the phenomenal success of Su Doku, which was first published in The Times only 11 months ago and now tortures millions of minds every day in 55 countries. But as the hunter-gatherers among you breathe a collective sigh of relief that your reasoning abilities have not been rendered inferior, it is worth asking how the mind of a Su Doku champion works.

You will have noticed that Nina Pell is a mathematician. Is this significant? Well, yes and no. As we know, Su Doku is a test of logic, not arithmetic (Killer excepted), and this is the key to identifying those who can unlock its more gruelling challenges, says Robin Wilson, Professor of Mathematics at the Open University and the author of How to Solve Su Doku (Infinite Ideas, £4.99).

“People who are good at Su Doku think logically. They like solving puzzles but they don’t have to be mathematicians,” he says. “Classicists would enjoy them, because they are about decoding, about logic. Mathematics actually is logic, and Su Doku fits in with combinational mathematics, the study of arrangements, which involves counting and arranging things. So if you are a mathematician you are more likely to be good at it — but if you are innumerate and can do it, this shows you think logically.”

What singles out mathematicians from those of us who are merely able to grind through a fiendish by using our logical skills is a thirst for creative mathematical thinking, Wilson explains. Like philosophers who find patterns in concepts, mathematicians think broadly and imaginatively. “Pure mathematics is done for its own sake. To us it’s an art like music, rather than a science as it’s often taught. Creativity is at the heart of it.”

Does this mean that someone who is a mathematician and brilliant at Su Doku is likely to be headhunted? “Miss Pell would be ideal for codebreaking, or any job in which you have to take an analytical approach to a problem,” Wilson says.

To find out more precisely what is going on inside the mind of a Su Doku expert we must return to psychology. Stewart points out that Su Doku taps neatly into a specific type of intelligence identified by psychologists when they have sought to understand what makes people clever. First, he suggests, consider crystallised intelligence, which concerns general knowledge, banks up over time at the back of your mind, and can be called on when needed, say, to do a crossword. Second is fluid intelligence, which relates to pure problem-solving and works like a short-term mental notepad at the front of your mind. “This is a part of you that you can apply flexibly to lots of problems. If you’re doing a Su Doku puzzle you have to remember a lot of numbers that haven’t been used up — so you have to hold all these pieces of information in the mind at the same time as you’re entertaining a range of possibilities.

“You can remember a lot of stuff but you can’t store that much information at the front of your mind. People who have highly developed fluid intelligence can hold new stuff in their mind while they think about something else, and if you’re going to be clever the best thing you can have is this short-term memory, sometimes called a working memory. It’s like a workspace for your mind and you use it while you think over things.”

Skilled chess players have a high level of fluid intelligence, as do bookies at racecourses, simultaneously working out changing odds and taking money. And yes, says Stewart, as measuring fluid intelligence is key to determining how clever you are, it follows that people who can cream through fiendish grids are bright.

The downside of fluid intelligence is that, unlike crystallised intelligence, it deteriorates with age — like other parts of the body the mind loses its elasticity. But in Su Doku this can be compensated for by practice, which enables you to build up strategies and a knowledge of the compiler’s mind which you may not be able to articulate but which will help you to solve puzzles.