杏吧原创

FOR mathematician and author Alex Bellos, the paper and pencil logic puzzle is 鈥渙ne the most addictive products鈥� known to humans, 鈥渁 metaphor for life鈥� 鈥� and, less hyperbolically, 鈥渢he most fun you can have with a pencil and paper鈥�. Whether you agree depends on your view of logic puzzles. I don鈥檛 much like them. But I do like Bellos鈥檚 book, The Puzzle Ninja.

Sudoku is one of Japan鈥檚 best known exports. Of the US鈥檚 top 50 bestselling books in 2005, six were Sudoku titles. The craze gave people an appetite for more, a hunger newspapers were happy to feed. Like many puzzle fans, Bellos started with a Sudoku problem. When the buzz began to tail off, he went hunting for new thrills.

But Bellos went further than most: 鈥淚t was the first Japanese puzzle to hook me, a necessary gateway drug to the far Eastern pharmacy of magical brain food.鈥� Since then, Bellos has been on a journey of enlightenment to Tokyo, the puzzle capital of the world, and brought back fixes more potent than Sudoku. There are, we learn, hundreds more, such as Kakuro, KenKen, O鈥橢kaki and Hashiwokakero, puzzles that 鈥渋nspire and intoxicate more than Sudoku ever did鈥� .

Bellos takes us to meet Japan鈥檚 elite enigmatologists. There鈥檚 62-year-old Nishio, with a Sudoku-solving technique named after him. And 57-year-old Miyamoto, who has published 200 books about puzzles. For years, he started his day at 2 am by creating puzzles he uses to teach young children maths. Recently married, he now lies in until 4 am.

There鈥檚 a new generation too 鈥� like 24-year-old 鈥減uzzle ninja鈥� Edamame (yes, soya bean pod), a former winner of the World Puzzle Championship, who co-runs a fanzine publishing 鈥渟ome of the most fiendish logic puzzles ever to have made it into print鈥�.

But the real point is the puzzles, with more than 220 examples, drawn from 25 different types of brain-teaser 鈥� most of them unknown outside Japan. Like Sudoku, they are set in grids and have very simple rules.

Bellos introduces each puzzle by explaining how to solve it. He observes that the popularity of grid-based puzzles is striking, given that poring over them at lunch break or morning commute is the closest most of us will get to doing real mathematics. As Bellos says, the strategies you discover are like theorems: 鈥淥nce you have nailed the strategy, you can reuse it鈥� without proving it again.鈥�

Japan鈥檚 puzzle culture goes back to least 1727, with the appearance of Japan鈥檚 oldest puzzle book, the Wakoku Chie-Kurabe. This was a departure from popular books of the day containing puzzles rooted in arithmetic. Instead, it was filled with brain-twisters that drew on different branches of mathematics, such as how to fold a paper sheet into a specific shape.

鈥淪ome puzzle designers were mysterious creators, like 鈥楲enin鈥�, who hasn鈥檛 been heard of for six years鈥�

Despite the long tradition, most of Bellos鈥檚 puzzles were invented by readers of two rival and hugely influential magazines launched in the 1980s, Nikoli and Puzzler. They were labs where puzzle designers could use their weird alchemy to twist old ideas into new forms. Some were mysterious creators like 鈥淟enin鈥�, who invented three now classic puzzles, Slitherlink, Hashiwokakero and Nurikabe, during a period of intense creativity when he was in daily contact with puzzlers. He hasn鈥檛 been heard of for six years now.

Despite chatting to many of the best-known designers, Bellos never quite nails why Japan leads the world. Perhaps these beautiful handmade puzzles resonate in a culture that values objects such as miniature gardens or bonsai. Perhaps it is to do with the stereotypical Japanese trait of perseverance. Or perhaps it is just that those rival magazines of the 1980s inspired a competition to produce ever more devilish ways to spend a lunch break.

This is a fun and infuriating book. Just remember an eraser.

This article appeared in print under the headline 鈥淕etting a fix on puzzles鈥�