On online message boards, particularly 4chan's /v/, people mix the word for Japanese ritual suicide, "seppuku," with "sudoku." The typo has since spread and became adopted in a similar fashion to "pwn" in regards to "own."
The puzzle consists of a 9x9 grid which is partitioned into nine 3x3 boxes. Typically, 20 to 25 of the 81 cells are pre-filled with one numerical digit. The objective is to fill the remaining cells such that each digit (1 through 9) is represented in every row, column and box.
Easy to moderate puzzles can be solved via simple elimination.
More difficult puzzles require some "what if" propositions to solve.
Solving Sudoku by hand is a routine diversion but writing a program to solve or create Sudoku puzzles is a more interesting challenge.
as of right now, the current world chamption Su Doku player is a girl named Keira, but 2 others, Pauline and Alissa, are a close second and third.
So one has 9 3*3 matrices, the numbers 1-9 inclusive with no repetitions for each 3*3 matrix. Then combine the 9 3*3 matrices so the supermatrix has numbers 1-9 in each row and each column without repetition..
2) Guess at one where a single digit must belong to one of 2 positions. Follow step 1, and if you run into an error, that guess was wrong, and the number must rest in the other position.
3) One can adopt another strategy.. For instance, if there are 4 digits possible for a space, say, 2,3,4,5... and in another submatrix space, there are only 2 possibilities, say, 2, 3.... then the probability of the 2 being in the space with only 2 choices is larger than the probability of the 2 being in the space with 4 choices...
4) Many times, the puzzle will be lacking in 1 or 2 numbers, with a lot of the other ones. This is meant to confuse you. Do not pay attention to the numbers which are missing and try to fill those in. Instead, when it comes time to guess, try to fill a row or column so that the row or column has lots of obvious fill-ins.
5) When you guess, keep track of the number of the guess, like, "OK, this is the first guess..." then, if you must "second-guess," and that guess is wrong, the first guess was wrong as well... this is why one guesses only when there there are only 2 possibilities...
6) I have guessed up to the 8th level, but, as I get better, it only takes me 3 or 4 levels... Ah, hell, just Google for a Sudoku solver !!! I'm sure a million have already been written !! Only takes a bit of linear algebra !! Thanks..