13 September 2005 · 9 comments

A couple of weeks ago, the Sunday New York Times featured a new puzzle called sudoku, which is apparently popular in Japan. It’s a sort of self-checking number-based crossword without clues. Confused? Don’t be. There’s only one rule.

Given a 9×9 grid, fill in all blank cells making sure that each row, column, and 3×3 box contains each number from one to nine.

The above puzzle is very, very easy. Believe me: they can be much more difficult. Brain-wrackingly difficult. Sudoku are rated in difficulty based on the numbers provided, the ease with which other numbers can be found, and the number of guesses required to solve the puzzle.

The real problem is sudoku is addicting. Last night in the grocery store, I saw a sudoku magazine. I tried to resist the urge to purchase it, but failed. I spent most of my evening doing sudoku. I solved easy puzzles, then medium puzzles, then hard puzzles.

I’ve spent too much time this morning trying to solve two difficult puzzles. I’ve exhausted elementary logic tricks and need to find some more elaborate methods of finding the correct numbers. I’ve gone to the web in search of help, and found:

Now, if you’ll excuse me, I need to go back to the two sudoku that I’m stuck on. Must finish. Must.


On 13 September 2005 (09:29 AM),
Amanda said:

I have been totally and utterly addicted to sudoku since it was featured in USA Today in July.

Best puzzle ever.

You can download a 28-day trial from Their rating system is a bit wonky, though. For example, the medium puzzles are pretty hard. The hard puzzles, well, I’ve only managed to solve two of the approximately 50 I’ve attempted. The very hard puzzles aren’t even available on the trial version. That scares me.

On 13 September 2005 (12:29 PM),
Courtney said:

A friend turned me on to Sudoku about a month ago and I have completed 3 puzzles EVERY day since (easy, medium, hard.) I found a great site with free puzzles that change daily: You can do them online or print them out. I’m totally addicted and glad to know I’m not the only one. Andrew asks me why I do them…he should just try one and see for himself!

On 13 September 2005 (01:04 PM),
Colleen said:

I adore Soduko! I’ve always loved logic puzzles, but I think this is my favorite. There is also a Mac App for Dashboard, love it!

On 13 September 2005 (02:30 PM),
J.D. said:

I’m pretty excited here: I just solved my first “challenger” level sudoku (to use Dell’s terminology). I bit the bullet and scribbled candidate numbers from the start, and it helped. Once I’d entered all the candidates, I was able to find one weak spot and then the entire puzzle toppled (though in slow motion).

On a whim, I timed how long it took me to do one of each skill level in my magazine. It took me 10:37 to solve the easy puzzle, 16:43 to solve the moderate puzzle, 23:53 to solve the hard puzzle, and 28:59 to solve the challenger puzzle. (Note that I’ve failed at three other challenger puzzles; they have me stumped.)

On 13 September 2005 (02:43 PM),
J.D. said:

In contrast, the easy puzzle I included in this entry took me 7:28 to solve. I’m sure there are people who could do it under five minutes. Maybe in under three minutes.

On 13 September 2005 (03:24 PM),
Count Dooku said:

Did somebody say Santoku?

On 13 September 2005 (07:55 PM),
Nikchick said:

I recently got hooked on these puzzles too, and have the application for my Palm. I spent an entire flight working on one puzzle. Kate is much better at them than I am.

On 14 September 2005 (01:47 PM),
Amanda said:

Yeah. Your example puzzle was definitely an under three minute super easy one.

On 15 September 2005 (12:13 AM),
John said:

I’ve completed one of these puzzles, and was actually sweating before it was over. Dunno what skill level it was – probably “stoopid easy” – but I was plenty frustrated. Handling numbers is normally a trivial matter for me, but that puzzle left a mark.

Thanks, but I’ll stick with my normal regimen of crossword puzzle, cryptoquip, and jumble. At least I feel comfortable doing those with a pen.


On 15 September 2005 (06:45 AM),
Kristin Wold said:

Here’s another cool sudoku site to add to your list:

Online solver with five new graded puzzles every day, hints, pencilmarks, and an archive with over 500 puzzles.

On 15 September 2005 (10:28 PM),
Geoff said:

The miniclip website is weird. I just finished the hard puzzle in 6:02 and the easy in 5:58. I can’t beat the medium in under 8.

On 18 September 2005 (03:21 PM),
Olivier Verdin said:

Check out Sudoku Prime and play multi-user Sudoku puzzle with your friends…Have fun!

1 Daily Sudoku January 15, 2006 at 22:38

A Sudoku weblog is a great idea! I started a daily email subscription or RSS feed of sudoku puzzles. Please try it out and let me know what you think. Thanks.

2 Dan February 25, 2006 at 19:34

I found a pretty cool Sudoku site. It’s called Some of the puzzles are pretty tough. Here’s the link for it.

3 AndreL March 5, 2006 at 23:07

“Computer Aided Sudoku” free excel game to download at will help you and give the solution (only if you need it)

4 Rijk Willemse April 7, 2006 at 04:23

I am addicted to Sudoku! I made an inventory of methods for solving even the most difficult Sudoku. Start with looking for duo’s, it’s an eye opener!
Check for details.

Good luck!

5 AndreL April 25, 2006 at 05:06

SUDOKU EXCEL free download

“Computer Aided Sudoku Excel” includes now new features :
– generator of sudoku puzzles to print or to play
– helper solver
– SURPRISES when you solve the sudoku without help
– HISTORIC records all the plays. Partial replay.
– Sudoku CLINIC for analysing sudoku
Enjoy playing this free Sudoku Excel game on your computer.

6 Danny May 29, 2006 at 11:53

Online sudoku for kids with images of Garfield, Harry Potter, …

7 Victoria June 26, 2006 at 13:52

My math teacher gace me a sheet that she copied out of one of her books, and told me how to do them. I started working on it im my next class. I was so much fum! The next day, I went up to her and got another ome! It was so much fun! The thing is that they are very addicting! :-)

8 Geir Homo April 25, 2007 at 00:48

Are you gay??? this sudoku is all to easy:O

9 Abby May 24, 2007 at 18:01

I love sudoku. It is awsome. Once I did a level 100 in 2 minutes. They r awsome:)

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