This is the heading page for the online version of the Sysudoku Guide. A hierarchy of other pages are accessed by dragging off menus to the right.
“Sysudoku” stands for Systematic Sudoku, a system of solving the sudoku number placement puzzles that appear everywhere in newspapers and magazines. Hundreds of books offer collections of puzzles, many advertised to be very hard, to extremely hard, to insanely hard. While internet forums entertain expert programmers with competing ways to solve these puzzles by computer programs, comparatively little information is available, despite public interest demonstrated, on how best to solve these puzzles on your own brain power.
The Sysudoku system is engineered to take advantage of universal human abilities, and for puzzles of every difficulty level. For very hard puzzles, the system supports templates for universally available office software, to make Sudoku solving these puzzle an especially pleasurable challenge.
Sudoku is not a math game, or a logic game. The game pieces are digits 1 – 9, but with no numerical properties. They are just familiar symbols. Sudoku is a constraints game, played on a 9 by 9 grid divided into nine 3 by 3 boxes. A set of placements, the givens, are made on cells of the grid to define the puzzle. The givens, plus the placements you make, are the clues. No givens of the same value are in the same row, column or box. The object of the game is to fill the remainder of the grid while maintaining the same constraint: no clues of the same value in the same box or line. This guarantees that every row, column and box will contain all 9 values.
This sounds so simple, that if you are a beginner, you may have to try it on a few Sudoku to realize that it takes some kind of strategy to succeed. The pages of this guide explain a single process for human solving of Sudoku puzzles. It’s just that harder the puzzle, the further you go in the process. If you are a beginner, you will not need to go very far in these pages to solve newspaper and magazine puzzles. But then you may want more, and there is a lot more you can do.
If you are an experienced Sudoku solver, the attraction of these pages is that so much of it is done in an efficient, uniquely different way. Candidates are identified differently and posted in cells differently, for good reason. Methods are explained with reference to common principles. Spotting guidelines are included. Graphical illustration of these methods is unmatched anywhere else. Methods are sequenced logically, around helpful visual tools constructed as needed. A compact tracing system supports complete documentation of a solving path. A ©PowerPoint presentation file proves to be an ideal tool for recording complete solutions. And also, there are concepts and techniques voiced, to date at least, nowhere else.
Regardless of prior experience, the best way to start is the Sysudoku Basic page for an overview of basic solving, then settle down with Begin With The Bypass.
Basic solving identifies and marks the possible placements of values in cells, the candidates. Harder puzzles require this task to be completed for advanced solving methods. The Sysudoku version makes placements while achieving this task, reducing it, or avoiding it in easier puzzles.
Sysudoku Basic concentrates human ingenuity on the currently simplest task. The beginning phase, the bypass, gets the most placements from the fewest candidates. Only the givens, the placements already made – the clues – and the most telling of the candidates, are involved. Then in two more basic stages, pairs of strongly linked candidates are added. Box marking adds linked pairs in boxes. Line marking adds the links along rows and columns, while completing all candidates line by line.
Sysudoku Basic enables you to solve most Sudoku puzzles, and to read through all the reviews of more advanced, to extreme, to monster puzzles on this blog. Sysudoku Advanced pages equip you for the hard puzzle collections offered in books and web sites. They provide a plan of attack, with the sequence of actions, why they work, and how to recognize when they apply. The methods are labeled as “advanced”, not because they are complicated, but simply because they depend on having all candidates, and therefore follow basic stages
Both basic and advanced Sudoku are analyzed in these blog posts, usually among puzzles pre-selected for collection reviews. The posts provide very worthwhile examples, especially for those willing to read through traces by filling out grids, and to consult this guide to pin down exactly why each move is made, and to invest in the tools used here to reveal the logic of the solving paths.
The Sysudoku Trials pages describe the Sysudoku alternative to arbitrary guessing when you are stumped by a Sudoku. Here, a trial is the assembly of candidates into true or false armies of candidates and trying one army. Of course, true means “in the solution” and false means “to be eliminated”. There is even a “breath first” version of the Sysudoku trace to discover if a false army is revealed by a humanly observable path to a contradiction.
Monster Methods is a set of Guide pages yet to be written. Monster puzzles are those so saturated with candidates that advanced techniques cannot be attempted. It awaits a return of this blogger to the review of progress made in the programmer forums to find logical and humanly accessible techniques. Currently posted Sysudoku solutions depend on trials.