Who wants to ruin a millionaire? | The Guardian

In the end, Eternity only lasted seven months, but there were probably sound commercial reasons why Christopher Monckton chose not to call his fiendish 209-piece jigsaw puzzle Just Over Half a Year. Calculating that it would take at least three years - if not quite an eternity - to solve, the aristocrat and former adviser to Margaret Thatcher offered £1m to the first person to complete the puzzle, comfortable in the knowledge that recouped profits and a special insurance policy would cover the payout. Everyone, Monckton accurately reckoned, loves a challenge and the promise of great wealth; predictably, the game sold by the hundreds of thousands.

Not everyone, on the other hand, is a Cambridge mathematics PhD with a persevering spirit, friends at the highest level of world-class number-crunching, and plenty of time on his hands. Alex Selby is - and last Thursday, two years ahead of schedule, Selby and his friend Oliver Riordan, a mathematician at Trinity College, Cambridge, were revealed as joint winners of the £1m prize. Monckton had already announced that the premature victory would force him to sell his £1.5m, 67- bedroom Aberdeenshire pile. "Eternity was the best-selling puzzle ever. I'm delighted it's been solved," he said, unconvincingly.

Selby, 32, and Riordan, 28, who posed for pictures resplendent in patterned knitted jumpers and sensible haircuts, seem to typify a certain academic type renowned - to put it diplomatically - more for their fluency with numbers than for their acquaintance with the cutting edge of dance music. The type that save their energies for programming computers in arcane languages, solving Fermat's Last Theorem and winning million-pound prizes.

"We were a bit lucky," Selby says modestly. (Riordan is in Germany, visiting his girlfriend.) "The nature of the solution is that you have to keep trying lots and lots of things, so if the answer comes up in the first 100,000 tries, you're lucky."

Eternity was a jigsaw puzzle in which every piece was the same colour and all the edges were straight; the aim was to align the pieces to create a 12-sided shape. To many, it sounded like a game with all the fun taken out - but to a certain mindset, it represented the throwing-down of a gauntlet. Even so, Selby barely looked at the game for six months after receiving it as a birthday present. "Some friends were messing around with it, and they got me interested," he recalls. "I thought it would be impossible - I mean, who would offer a £1m prize if it wasn't? - or else that someone would already have solved it."

The London-born son of a maths teacher and an accountant, Selby grew up with numbers in his blood. After finishing his PhD at Oxford and Cambridge, he spent a year in the US, teaching and researching at the University of Texas in Austin; on his return he took a research position at New Hall, Cambridge. But then in 1999, dissatisfied with his achievements in a field dominated by geniuses in their early 20s, he gave it up. "I wasn't making the progress I wanted to, and I always thought I'd be better at computers than mathematics," he says. "So I thought I'd mess around for a while with computer things that were interesting."

He had a little money set aside, so was able to manage without a steady income, tinkering with various projects at home in Cambridge. He planned to write a program for playing Go, the Japanese strategy game that occupies much of his leisure time. "I thought maybe they'd make some money, and then I'd be very lucky because I'd be doing what I liked doing and making money." It all happened - but not the way he expected.

It was a muggy night in May when the programs Selby and Riordan had written to crack Eternity finally spewed out a solution. They had been using two ordinary home PCs to calculate the difficulty of each piece and then attack the hardest pieces first. "I couldn't sleep that night, so I went down to my study to check the computer," Selby recalls. "I noticed it had solved it, but I thought there had to be some kind of mistake. I spent the whole night checking, all the next day, thinking: this can't be true!" But it was; and two copies of the solution were dispatched in that evening's post - one to the manufacturer of Eternity, one to his solicitor. The rules of the game meant their solution could not be examined until the end of September, and an agonising wait began.

In the end, the Eternity people informed the winners of their achievement in a manner that came as close to torture as possible without infringing the Geneva convention. First, public relations people made contact, dropping hints; later, they were told unofficially that they might be the winners. Then news stories started appearing about Monckton and his proposed house sale, and still they didn't know for sure. "It was pretty nerve-racking," says Selby. "I mean, I don't want to come across as ungrateful. But it was nerve-racking."

Their victory was finally confirmed by letter last week. There was no one moment of awestruck realisation, he says, no single night of drunken congratulations. "Although I'm sure we'll have a party. There'll be some sort of celebration."

Does he feel guilty about ejecting Monckton from his home? "Not entirely. It's slightly naughty of him to put that about," says Selby of the house-sale story. "I think you need to take that with a grain of salt. Maybe he does have to sell his house but I don't think it's because of the puzzle. And he does have another house, apparently."

Monckton has remained aloof, recuperating from illness in Cyprus last week instead of appearing at the prize-giving ceremony at Hamley's in London. Selby isn't gloating at the two years by which he beat Monckton's deadline; it is, he says, so hard to predict the difficulty of a puzzle such as Eternity that the actual and predicted solution times were in fact surprisingly close."You could easily make it a hundred or a thousand times more difficult than you expected just by changing something very slightly," he says. "It's astonishing that it had roughly the right time scale - it could easily have been a puzzle that took one week or a million years."

There will be no fairy-tale ending; no satisfying reversal of fortune in which Selby, the plucky underdog, ends up living in a mansion much like the one formerly occupied by the fiendish puzzle-master defeated by his cunning. Cambridge property prices wouldn't allow it, but anyway, Selby is more than happy in the rented house he shares with several others. "It's not really my thing. I'll probably give some of it to my family, some of it to charity, and then I'll have to figure out what to do with the rest," he says. He sounds awed by the prospect; this is one condundrum that no computer program, however ingenious, can help him crack.