Solving Sudoku - tactics

Sudoku, the puzzle of this decade,  is quite a fun to solve.!
But if you find it boring and think it is fun only as long as one can solve it.. then do take my word..

"Sudoku is lot more fun to solve when it gets harder, but only if you have the right tactics and solving strategies."

Over the next few weeks we will discuss solving tactics of varying levels and difficulties starting from the easiest to the difficult ones. We will only discuss the tactics for 3x3 sudoku ppuzzle..But before we start on that, I have a few points to make:

• If you want to experience the "fun" of solving tough Sudokus (and actually solve it) then you have got to religiously solve them (atleast one) every day. Take the newspaper you subscribe to and spent some quality time daily.
• Iif you want to become a pro in solving Sudoku then you must go a level further, download any good Sudoku Software you can find online. Load the puzzles either inbuilt or the ones you come across (in newspapers, forums etc.) and solve them regularly. (at least 3 per day of differing difficult levels).
• Time yourself when you solve. This way you will know your progress.

Recommendation:
"Simple Sudoku" software in the website given here is what I use.
Link: www.angusj.com/sudoku/

I would suggest that for you as well. But it is not necessary, you could use any software you find comfortable.

Disclaimers:
I am not associated with the author of the simple sudoku software. I found the names of the tactics discussed by this author very intuitive So I will use the same here, however the tactics themselves are very general and easy to relate to.

Legend:
N - numbers from 1 to 9
P - place or a cell; there are 81 cells
R - Row; there are 9 rows
C - Column; there are 9 columns
B - Box of 3x3; there are 9 boxes
G - Group ; it can either be a R or C or B

Terminologies:
"Naked N" : N is the only possibility at a given P and no others Ns are possible
"Hidden N" :  N is one among the posibilities at the given P

"Locked N" : N occurs only at the mentioned P and no where else in that G

Level One:

Now we will discuss level one tactics. These are the basic tactics that will help you solve most of times with the difficulty levels of the Sudoku. You might consider these to be trivial, but sometimes these overlooked tactics would have been the bottleneck for some to achieve a good timing.

Naked Single 

If for a given P in a G, only one N can be assigned, then that P is solved with N as the solution.

Hidden Single 

If for a given N, only one P can be assigned in a G, then that P is solved with N as the solution.

Locked Candidates (2 tactics)

• If a given N is locked to a R or C of a given B, then exclude that particular N from the rest of R or C which is outside of the B
• If a given N is locked to a B of a given R or C, then exclude that particular N from the rest of B outside of the R or C

We will discuss the level 2 tactics next week..
until then Happy Sudoku Solving..