One of the things I that drove me crazy about Sudoku is how difficult it is to return to a puzzle if you get interupted. This system allows you to walk away from a puzzle at any time and return exactly where you left off.

**Signing Up**

## Step 1: What you need to begin

1. A sudoku puzzle. I enlarged this one (which was the puzzle that appeared on Sudoku.com on July 8, 2006.) to make photography easier. I find this system works better on larger puzzles.

2. A pencil, Not a pen. A pencil.

3. An eraser.

## Step 2: Fill in the "Missing Grid"

Enter the numbers 1 through 9 in a "tic-tac-toe" pattern in every blank box.

## Step 3: Erase "Across"

So the first number (in the upper right corner) is a "6". Erase every other "6" in that row. Once you have completed the erasing, draw a line across the top of the number to indicate that you have cleared out that line.

## Step 4: Erase Down

## Step 5: Erase "All Around"

Now you have eliminated all the sixes from all the other blocks. That indicates that a Six canot appear in any of those blocks.

Keep going, repeat those same three steps for all the other pre-printed numbers in the puzzle.

thanks for the advice

this is bloody cheap trick you mentioned above huh..

this is great. it made my mind explode like Chinese New Year. :)

There are a few simple techniques to solve Sudoku and they are:

Last Digit - http://www.livesudoku.com/en/tutorial-lastdigit.ph...

Hidden Singles - http://www.livesudoku.com/en/tutorial-hiddensingle...

and Naked Singles - http://www.livesudoku.com/en/tutorial-nakedsingles.php

You also need to understand what boxes are (see image below)

I used dots for about a year and eventually gave it up. Not sure why anymore. I think the dots are more common in Europe. My personal challenge now is to do my solving with no jots whatsoever. I have worked my way up to the Nikoli X-treme book this way. I have to revert to jots about half the time in that book.

Am I the only person who uses a "dot" system instead of numbers? The dots are so much easier to fit into the puzzle and easy to recognize. There are 9 squares. The squares on the left are 1,4,7; middle, 2,5,8; right, 3,6,9.

I agree that Sudoku is simple logic. So many people take one look and assume it's math related -- and they give up before trying. I am addicted to Sudoku. My husband bought me a Sudoku calendar. Each puzzle is past difficult and really taxes my brain.

Does anyone have tips on how to solve the extremely challenging one? I'm feeling stupid. ;-)

You know the middle block has to be the middle row somewhere, but not where. That said you can fill in the square for the right hand block because you know the middle row is taken.

Last for the comment, look for rows, columns, or blocks with only 2-3 empty spaces when your stumped. You may see that it needs a 1, and a 5, but one of the spaces in a line already use the 5. So you can put the one in that spot and the 5 in the other.

Maybe I'll actually write up my own how too. Ya think?

If anyone is lost or stuck, you can try my simple sudoku solver!

http://www.simplesudokusolver.com/

Should be really fast and easy to use. Let me know if you have any feedback!

Alright its still a god technique but its not fast enough. I need a fast one

Alright its still a god technique but its not fast enough. I need a fast one

Wow! I was struggling trying to find a technique to help me with Sudoku and this was it. It was simple and straight to the point and it does work with the hard ones. The only thing wrong is that you do have to think...............TO PICKUP YOUR PENCIL AND ERASE! That is all I thought about. Try this it works

Nice one! You are implicit using some of the solving techniques mentioned here:

http://sudokusolvertips.com/category/sudoku-resolving-strategies/

aaawwwwwwesome

without thinking is preposterous as the "solution" you give is precisely what we all do when we solve à sudoku ... Exception we do it in our brain and do not write it down.

sorry "except" not "exception"

Difficult to write english without an french auto correct !!!! ;)

Presumably 'broper's somewhat exotic spelling is not for real!

(who is Ible?)

love this system

man pscovio

I'm pretty sure he just means one out of the nine "boxes" in the main grid. I guess if "nona-" is the prefix for "nine", then he'd be talking about a "nonadrant". LOL

I came to this web site hoping to find out where my thinking is muddled when I get down to the same three possible numbers in any box, column, and/or row. I can't seem to figure out how to further eliminate possibilities. If you - or anyone else reading this post - can help, I'll check back!

Thanks!

Granny H

If you just have a place where you have the same three numbers appearing in the same box, column, and row, but there are other bits left to solve as well, try to work on other parts of the puzzle. Somewhere in the puzzle, there's some way to eliminate some of those numbers. You might wind up coming at it from a really backward direction, but it's there.

I think I stated my problem poorly. Let's see ... What I meant was more like what you say in your second paragraph. When I have several "other bits" of the puzzle left here and there, and the same two or three numbers are the only ones available for all of those little boxes, I don't know how to eliminate without guessing. And guessing NEVER works for me! I'll come back again when I bump into a good example to give you.

Again, thanks!

Granny H

How do you soften the puzzle? Select a pattern of rows and columns which have the highest number of digits. Proceed to tackle them in descending order of number of digits.

Once you have selected a row or column with the highest numbers, attack it in an oblique manner. For instance, if you are tackling the upper row, you may find a number repeated in the sub-rows. Now try to fit that number in the 3rd row by looking into the sub-columns.

Attack all 3 horizontal rows and 3 vertical columns turn by turn, systematically in this manner and you would have softened up the puzzle a bit. Repeat the entire process and you'll get a few more discoveries, maybe one or two.

Once the puzzle has become soft, you can start the slog phase. It is NOW that you need a pencil & eraser.

Don't make all entries (from 1-9) in every box. You can straightaway start with the missing numbers ie possibilities.

Once you have entered all possibilities, start looking for singletons - row-wise, column-wise and grid-wise. Having caught singletons, erase the corresponding possibilities row, column and grid wise.

Now look for pairs, triads and even in a few cases, 4-digit patterns. Having identified a pair, triad or a quad in a row/column/grid, proceed to erase the numbers in the remaining possibilities.

Don't forget, once you have discovered any digit, always look obliquely in horizontal as well as vertical directions to fit it into a suitable blank space, as I have described in para 3 above. It helps.

Ultimately you will reach a point where all the solutions cascade into view.

One thing that is the case with most Sudoku puzzles is the symmetry. You notice the symmetry at the start and as the solution proceeds, you will notice a symmetry in the solution. In this case, this is where I agree with Eddie Chong on the "beauty" of the puzzle. What I detest most are those puzzles where you are reduced to guessing (rather than using logic and reasoning) which of 2 or 3 numbers to to choose in 2 or 3 squares and use "trial and error" to solve. This is typical in most Sudoku magazines that have "extreme" or "brutal" puzzles. To me, you should never have to resort to "trial and error" to solve the puzzle. As Sir Arthur Conan Doyle had Sherlock holmes say "Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth."