Warning! Sudoku is an apparently simple, cunningly deceptive, and utterly addictive game!
Unprotected exposure to this game, whilst not life-threatening, can result in mood swings, brain and eye strain, chores remaining undone, and failure to attend important meetings!The concept is simple:
Fill the 9×9 Puzzle Grid (totalling 81 Cells) with the numbers 1 to 9 so that each Box (the grid is subdivided into nine 3×3 Boxes), each Row and each Column contain the numbers 1 to 9.
Each number may only appear once in each of the Boxes, Rows, and Columns.
The puzzle setter provides some numbers as clues. These clues are called Given Numbers (GNs). Puzzles usually only have one correct solution.
This illustration from my book, Win At Sudoku, highlights the basic elements of the Sudoku Puzzle Grid.
The Puzzle Grid Elements
In the Win At Sudoku method, Columns and Rows are numbered from 1 to 9 to make it easy to refer to individual Cells as, for example (in pink), C5:R6.
The nine Boxes are:
(LT) Left Top – - – - – (CT) Centre Top – - – - (RT) Right Top
(LC) Left Centre – - -(C) Centre – - – - – - – - (RC) Right Centre
(LB) Left Bottom – - (CB) Centre Bottom – (RB) Right Bottom
The six Sections (three adjacent Boxes) are:
(L) Left – - – - (VC) Vertical Centre – - – -(R) Right
(T) Top – - – - (HV) Horizontal Centre – (B)Bottom
Do You Get It?
Since I published Win At Sudoku it’s become clear to me that the ‘Official’ Rules leave many people still wondering what the Big Deal is – where is the fun in just writing any old number in any empty Cell on the Puzzle Grid?
Well here is the Big Deal: There is only ONE correct position for EACH of the numbers – 1 to 9 – in EVERY Box, Row and Column.
And Boxes, Rows and Columns have intimate relationships with each other. So you need to SCAN related Boxes, Rows and Columns and use the GIVEN NUMBERS (supplied as clues to every puzzle) to work out the ONE & ONLY correct position for each MISSING NUMBER in each Box, Row and Column.
The next few pages (from the Win At Sudoku book) explain SCANNING and RELATIONSHIPS.
Scanning The Puzzle Horizons
Scanning skills are critical to your ability to Win at Sudoku because you need to use the Given Number clues (GNs) to turn all the Missing Numbers (MNs) into Found Numbers (FNs).
Row and Column Relationships are simple: they relate where they intersect.
Boxes are another story. Say you think that a specific Cell (say C6:R5) might be a 7. You need to scan the related Boxes, Rows and Columns for information about 7s and other available data such as positions before you make a decision – and in this example, you can see you are correct!
What you have done here is scan LC, C, RC, CT and CB Boxes – probably without realising it!
These are the other Box relationships.
One Last Thing…
Which troubles many people:
You are considering a specific number – say 7s – and looking at a Vertical section (3 adjacent Boxes) of a puzzle – say the Left Section. So you have to find 3 Cells in this Section where the number 7 is correct.
One of these 7s must be situated somewhere in the Left Column of this Section, one in the Centre Column and one in the Right Column.
It is also true to say that in a Horizontal Section of a puzzle one of these 7s will be in the Top Box, one in the Centre Box and one in the Bottom Box.
You can buy the (printable!) PDF version of Win At Sudoku at www.winatsudoku.com. The MOBI version (for Kindle) is available on Amazon. The EPUB version (for other e-readers) is available on SmashWords.