Wayne Gould admits that his wife is still better than him at solving the puzzles that he creates.

His Sudoku logic puzzles have been printed in newspapers worldwide since their launch last fall.

Demand for the game has kept the retired Hong Kong judge busier than ever.

``I retired so I would have more time, but now I'm even busier than I was before,'' says Gould by telephone from New Zealand, his home country.

It's hard to tell where he'll be next.

He bounces between his Discovery Bay home on Lantau and New Hampshire in the United States, where his wife Gaye is a professor of linguistics, and other parts of the world to which his new hobby has taken him.

He has two children, daughter Sally, 29, and son, Scott, 27.

For now, retirement can wait for Gould, 59. ``I'm just going to go on as I'm going,'' he says. ``[Sudoku] has been pretty handy and is selling very well.''

He won't disclose how financially handy the game has been for him but says two of his puzzle books are in the top 10 best-seller list in the United Kingdom. For about 4 (HK$55.81) one can own a book of Sudoku puzzles, a better seller, he says,

than the program that allows players to load the puzzles onto their computers and solve them.

After his initial retirement, in efforts to pass time and sharpen his computer skills, Gould developed the computer program that generates Sudoku puzzles.

Today, all he has to do is push a few buttons and a new puzzle appears.

To solve the puzzle, logic and reasoning are required. Sudoku uses a 3x3 square grid. Each square is then divided into another 3x3 box. The objective is to fill in the grid so that every row, every column, and every 3x3 box contains the digits 1 through 9.

Simple enough - but for those who get nauseous at the sight of numbers, Sudoku can also be played with letters of the alphabet.

According to Gould, the time required to solve either version of the puzzle is typically 10 to 30 minutes,

Sudoku is often compared to the traditional crossword puzzle but Gould says it's much different.

``It's not a complicated puzzle, there aren't any complicated rules and you don't need any particular language - no dictionary or library full of reference books, it's just between you and the puzzle,'' he says. ``I don't think the crossword puzzle will ever disappear. I don't think Sudoku will either.''

Gould says the crossword puzzle is still around for the same reason that Sudoku is: ``Today, you have to have a puzzle in order to be a newspaper.''

Sudoku can be found in newspapers, including The Standard, in 25 countries.

About 2,000 e-mail inquiries from players through to marketers flood Gould's inbox daily.

He says people of all ages enjoy the mind teaser.

`The great part is that there are cross-generations solving them,'' he says. ``Children are spending time with their grandparents, solving puzzles, no TV, just traditional pen and paper.''

Nobody quite knows who originally invented Sudoku but most guesses date from Leonhard Euler (1707-1783), a mathematical genius and native of Basel who, some say, invented his carres magiques or magic squares the same year he died. According to Gould, in the 1970s a Tokyo-based publisher spotted the game while studying in the United States, named it ``Su doku,'' meaning, ``solitary number''and started producing his own Sudoku magazine in Japan where it is still popular today.

According to European reports, right now, five monthly Sudoku magazines in Japan have a combined circulation of 600,000.

Gould was a lawyer for 13 years in Matamata, New Zealand, before coming to Hong Kong in 1982 where he worked his way up to become Chief District Judge in 1993. He retired from the Judiciary in 1997, immediately after the handover.

That same year, during a visit to Japan, he was in a bookstore where, not knowing how to read or speak Japanese, he was drawn to the puzzle which he first thought was a crossword.

He was intrigued. Later on he decided to take it with him to the United States and Britain.

In September 2004, Gould's first Sudoku puzzle was published in the Conway Daily Sun in New Hampshire where he has a home.

He has more ideas for other programs and puzzles up his sleeve, but is keeping them hush for now. The only detail he spills is that the next one also will be all about logic.

staff.reporter@singtaonewscorp.com

Try the puzzle: A2