Step 1: Elimination is the Way to Go!
Start with solving the definite ones in your newspaper. The rule clearly says that each number from 1 to 9 can occur only once in a row and similarly each number can occur only once in a column. Also each number can occur only once in the given nine boxes.
Go with it! Elimination is the way to go for each and every puzzle you take. And Sudoku is the master of it!
Start eliminating the doubted ones and Go for the definite ones in your newspaper.
Fill the numbers that are obvious. For example, in the image below, look at the second box from top left. Consider all the possible ways of number 3 in the second box and start eliminating the places where 3 can never come.
1. Top first row has a 3 already, so 3 can't come in the first row of the second box
2. Top third row has a 3 already, so 3 can't come in the third row of second box
3. Sixth column from left has a 3 already, which clearly tells us that 3 cannot come in the sixth column of second box.
Thus, three points of elimination makes the possibility of the occurrence of 3 in only one position as shown below.
Similarly continue with the other boxes by simply Eliminating!
Step 2:Elimination Continues!!!
So you are done with the boxes. And you are stuck up again.
Do not worry!
Start with rows and columns. Consider a row or a column which has more filled in numbers and check for the missed out numbers.
For example in the image below, look at the last row. There are only two numbers left out 5 and 7.
Now look at the columns corresponding to the missing numbers. The last column from left has a 5 already. So, this tells us clearly that 5 cannot come in the last sub-box of the last low.
This elimination now leads to us in filling up the number 5 in the other left out box of the last row and thereby filling 7 following that.
Always Remember to just Eliminate!
Step 3: Looking again solves the most of it!
"Awe! I am stuck up again!" is the common dialogue you would say when it comes to Sudoku.
But the only way to overcome this is to look at your puzzle again!
And check out if you have missed any number. Because most of the time it would be only one number after solving which will lead to finish up the entire puzzle!
Consider the image below. First row of it needs four numbers to complete (1,2,4,9).
Now look at the corresponding columns of missing numbers. In the 8th column from left you can find numbers 2,4,9. So the obvious number in the sub-box corresponding to that column is 1.
What is my best Sudoku level?
Step 4: Pairing is all you need!
So the elimination is done. And you got stuck up again!!
This stage happens with most of the Hard and very hard type of puzzles where u get stuck up even after following the previous three steps.
The difference between a very Easy and a Very hard puzzle is that you need to find one tricky number (let us name it as Tricker) which is quite difficult to find. As soon as you find that number, the rest of the puzzle becomes easier.
So what should you do now?
Its very simple but tricky again.
A number pair in the same box or in the same row/column is all you need.
If you cannot find the Tricker in the puzzle start searching for a number pair. And depending on this number pair you can easily locate your Tricker.
Let us look at the example shown below.
There are totally 3 number pairs in the image (14,89,78).
1. 1 and 4 are present in 5th row as well as in 6th row. So, the only possible location for 1 and 4 in the middle center box is 4th row. That means only 1 and 4 can come in those two places and not any other number.
2. Now, in 4th column,consider the numbers 8 and 9. these two numbers cannot come in the down center box because it already has 8 and 9 in the same box. So the only possible location for 8 and 9 is in the middle center box
With the above two points, you can easily locate the tricker of this puzzle (number 2) which comes in the middle center box.
After finding the tricker, the puzzle becomes easily solvable.
There is also one more number pair in the same puzzle(78) which is present in the first box from top left.
How to solve Expert Sudoku?
Step 5:Go ahead and finish up the puzzle!
Now you found the tricker of your puzzle!
So what are you waiting for?
Just go ahead and solve the rest of the Puzzle!
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Don'ts in Sudoku
1. Do not go in order.
It will only consume time.Solve your sudoku in a random order instead of starting it from 1 to 9.
2. Do not give up
When you get stuck, leave the puzzle for 10 minutes and come back again instead of continuously doing it. This small refreshment time will help you in a great way by looking at the puzzle in a different angle and thereby leading to solve it.
3. Do not get afraid of Very hard/Expert
The difference between very easy and very hard is that you need to find one tricky number in your puzzle.
So do not get afraid of Very hard and Start doing it!
Madhanraj on November 30, 2019:
Explained Nicely... Really helpful for beginners.. good job
Padmahura (author) from India on November 03, 2014:
Thanks everyone for your valuable feedback !
Reena Dhiman on October 16, 2014:
A good hub to decipher complex sudoku!!!! I like the way in which you have simplified this daunting game by using images.
Sarah LaFleur from Chicago-land on September 21, 2014:
I really like all the images you used to compliment your explanation... I wish you the best of luck with your HubPage!
Vaishnavi from Chennai on September 17, 2014:
Good start.. Clear and crisp with self explanatory images..
Robert on September 16, 2014:
Great post and a nice way to solve this puzzule. I always used to stay away from it, as i found it very complex and confusing :).. thanks for clearing it..