Sudoku-playing jurors

News.com.au 10/6/08

A MILLION dollar Sydney drugs trial has been aborted after it was found jurors were playing the puzzle game sudoku while evidence was being given.

The jury foreperson admitted to the judge that four to five jurors were playing puzzle games for up to half the time the trial had been going.

"Yes, it helps me keep my mind busy paying more attention. Some of the evidence is rather drawn out and I find it difficult to maintain my attention the whole time and that doesn't distract me too much from proceedings," the jury foreperson said after being questioned by the judge today.

The judge was alerted after it was observed the jurors were writing vertically, rather than horizontally. It had been assumed they were taking notes.

Solve the "unsolvable" Sudoku

Michael Mepham may have said goodbye to Sudokus which require "Ariadne's thread" (aka trial-and-error or forking or bifurcation) to solve, but some expert sites persist with these "unsolvable" Sudokus, in the hope that someone uncovers a hitherto unknown logical method to solve them. Could that someone be you?

Free sudoku puzzles

I have been tasked to find as many free and hard Sudoku puzzles on the net as possible to feed a recent addict.

Some sites offer "sample" puzzles while many others provide a few free puzzles a day. The Times is quite generous, since it archives around 2 weeks of Sudoku puzzles. But many of them are relatively easy and not what I am after.

I finally come up with 2 sites:

1. Free Sudokus by KrazyDad - free, 5 levels of difficulty, hundreds of Sudokus per difficulty level, in pdf files. Great for offline playing.

2. Web Sudoku - Millions of free Sudokus in 4 levels of difficulty. Choose a difficulty level and press for a randomly drawn puzzle for online playing. Time taken to solve the puzzle is recorded to compare yourself with the "norm". Even allow for "pencil marking" (i.e. entering multiple numbers in a single cell to aid thinking). Excellent for online playing.

These 2 sites should offer Sudoku addicts years of playing pleasure. Unless of course if they insist on playing hand-constructed Sudokus. Or unless if they, as I predicted, become fed up with this game soon.

Can the Sudoku fever last? (II)

In June, I posted a short entry on Sudoku entitled "Can the Sudoku fever last?" A visitor, who was either upset with what I wrote or my writing style, posted a rather critical comment.

I am sorry if my writing made the visitor lost interest in this hugely popular game. Here I just want to clarify one thing. He's right in accusing me of being all-write-but-no-do. When I wrote "but once I figured out how to solve the Sudoku puzzle, I have lost interest in it, since next time the same thought process will be involved", I didn't mean I could solve all Sudoku puzzles. Far from it.

I only said that I thought I knew what thought process was involved in solving Sudoku puzzles. As I wrote in yesterday's entry (the only other entry on Sudoku since the June one), "I only write about Sudoku as a phenomenon. Personally I don't like this game since I hate spending so much time and enduring so much frustration trying to solve the puzzle. I am just too dumb to play this game of logic."

So, back to the question of whether this fever will last. Yes and no. Yes, because more and more people around the world will discover this game and become addicted. No, because those who play regularly probably will lost interest well within a year. Those who find Sokudu too challenging will stop playing soon. But those who have no proplem with it will soon find it "monotonous" since the same thought process will be involved in solving the next one.

To keep the latter group of persons involved, Sudoku makers have to keep on devising bigger and more complex Sudoku, like the interlocking ones (the Gattai 5 or Samurai Sudoku), or ones involving more than 9 digits (The dodeka version has 12 4x3 grids, each grid involving 0-9 and A, B), or ones with extra requirements (The Times call it the Killer Sudoku).

What do you think?

Is trial-and-error needed to solve Sudoku puzzles ...

... or are you just dumb?

The truth is, most of the time, the latter is true. The vast majority of Sudoku puzzles can be solved by logic, and logic only. When someone claims that a certain Sudoku puzzle cannot be solved unless trial-and-error is used, you can almost be certain that he/she has not tried hard enough (or he/she is just plain dumb).

But there are indeed a small number of existing Soduku puzzles which do require trial-and-error. Read Michael Mepham's Farewell to Ariadne's thread?.

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"Ariadne's thread" comes from a Greek mythology in which Ariadne gives a thread to her lover to help him find his way out of a labyrinth.

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I only write about Sudoku as a phenomenon. Personally I don't like this game since I hate spending so much time and enduring so much frustration trying to solve the puzzle. I am just too dumb to play this game of logic.

Can the Sudoku fever last?

I don't know about you, but once I figured out how to solve the Sudoku puzzle, I have lost interest in it, since next time the same thought process will be involved. How monotonous.

But then I am also not a fan of crossword puzzle, and there are millions of people who play this game day after day, day after day.

Sudoku, the next great thing since the crossword puzzle?

I must admit I have never heard of a "hugely popular" game called Sudoku until today, when most Australian newspapers sing praise about it and will begin offering it to readers on a daily basis.

Basically, Sudoku is a puzzle which involves an 9x9 grid. This main grid is then divided into 9 3x3 sub-grids (or boxes). The rule of the puzzle, according to the official site, is to "fill in the grid so that every row, every column, and every 3x3 box contains the digits 1 through 9." Some of the numbers are given. The player then figures out the rest.

A typical puzzle looks like this:

Unlike crossword puzzle, solving the Sudoku puzzle only involves pure reasoning and requires no literary or mathematical skills.

The Sudoku program is created by a retired Hong Kong judge Wayne Gould.