What is it?
Sudoku-Help+ Solving Rules
Sudoku-Help Difficulty (SHD) Ratings
Sudoku-Help+ Puzzle Classes
Sudoku-Help+ Testimonials
Sudoku-Help+ ScreenShot
Sudoku-Help+Solver ScreenShot
A worked example of an extremely difficult puzzle
Sudoku-Help+ as an aide to puzzle construction
You can only get Sudoku-Help-Plus via
On receipt of your payment Sudoku-Help+ will be emailed to you
Sudoku-Help+ is everything Sudoku-Help was PLUS:
84 Classified & Rated Puzzles personally crafted by Greg Shalless. Includes 2 new puzzles in Version 1.3 to highlight a recently added Solving Rule, namely Pair Chains and another 3 puzzles to highlight the even more recently added Single Value Chains Solving Rule, now available in Version 1.4. Version 2.0 adds the absolute killer Solving Rule, Multi Value Chains, which solves the No. 77 puzzle that the Sudoku-Help-Plus solver was not previously able to solve, and adds a few puzzles that show the full potential of that new rule. And now with Version 2.1 a special one click button has been added to enable you to Paste in any of the free Puzzles previously published in mX Newspaper (and available online exclusively here at mX Sudoku Puzzle history).

NEW in Sudoku-Help+ Version 3.0:

- Much more powerful Single-Value-Chains rule.
- All new feature to highlight the last Elimination.
- The special "Paste mX Puzzle" button will now paste puzzles in the following format:
- A brand new SHD Ratings algorithm.
- A complete history Log of every Elimination performed by the Sudoku-Help+Solver.
- 3 Brand new Puzzles:
    No 82 - A Multi-Value-Chains monster with a 238 SHD
    No 83 - To highlight the new Single-Value-Chains code
    No 84 - A "Master" class puzzle that could not be solved by Version 2.4 but can be solved with the Master Class rule "Blocked Gridlock". However the new Single-Value-Chains code eats this puzzle for breakfast - so it's not "Master" class after all.
The ability to Convert any Numeric Sudoku puzzle to another Numeric or for that matter Alphabetic Sudoku Puzzle.
The ability to Transform any Sudoku puzzle by any one of eight transformations that preserve the puzzle, both in its 180o rotational symmetry and so that it is in effect identical to solve, but which make it look completely different .
A number of Cluedoku Puzzles which are Alphabetic Sudoku Puzzles where there is more than one solution. You must solve the Clue (the answer is hidden in the puzzle) to find the right one.
The Sudoku-Help+Solver which implements a number of Sudoku Solving Rules. It does not solve the puzzle other than as directed by you, where you click the appropriate button to execute that Rule across the puzzle. You can do this with Looping On (it keeps going till nothing more can be done with that Rule) or with Looping Off. It is intended that the Sudoku-Help+Solver will be used by you as an aide to learning how to implement its various Solving Rules by yourself. Results are shown in different Colours for each Iteration, and different Fonts for each Rule.
Every puzzle is assigned a numeric SHD Rating which is an estimate of the difficulty of solving the puzzle relative to the other puzzles. (Includes an attempt to rate unsolved puzzles).
Sudoku-Help+ Puzzle Classes are:
Novice (no Candidate Elimination required)
    - 26 Puzzles with SHD Ratings from 57 - 82
Player (Basic Candidate Elimination needed to solve the puzzle)
    - 30 Puzzles with SHD Ratings from 76 - 131
Expert (Complex Candidate Elimination needed to solve it)
    - 27 Puzzles with SHD Ratings from 93 - 238
Master (single solution but not solvable with Rules currently implemented in Sudoku-Help+)
    - 1 Puzzle with an SHD Rating of 163
(although Version 3.0 of the Sudoku-Help+Solver reduces it to the Expert level)
Sudoku-Help+ Testimonials
"As a work colleague of Greg's and a fellow Sudoku addict, I have had the pleasure of using Sudoku-Help-Plus as a Beta tester during its development over the last 6 months. It's really fun using it to create and test your own puzzles and subsequently to solve them. With Sudoku-Help-Plus anyone can become a Sudoku puzzle creator. I get really excited when I solve a puzzle using Sudoku-Help-Plus that I cannot solve manually on paper. You will find more solving techniques in Sudoku-Help-Plus and you will become an expert at solving Sudoku. Believe me it's worth more than $10.00!"

   Sangamnath Hulsoor (Melbourne, Australia).
"I find Sudoku-Help-Plus to be the fastest, most efficient way to quickly understand Sudoku puzzle-solving methods. It takes the tedium out of Sudoku and lets you concentrate on finding the solution."

   J. Reese Thomas (Houston, Texas, USA).
"I really enjoyed the Player level puzzles. It was also very pleasing to discover that an increase in the SHD Rating invariably resulted in a commensurate increase in the time it took me to solve the puzzle. Despite a predisposition to dislike them (because I'm a numbers man), I even found myself enjoying the Cluedoku puzzles. I am looking forward to refining my techniques, with the use of Sudoku-Help-Plus, so that I can solve the more difficult Expert level puzzles."

   Rob Pendlebury (Melbourne, Australia).
"Really impressive software! Anyone from the paper and pencil novice to math PhD's and everyone in between should enjoy Sudoku-Help-Plus. It has everything from basic solving grids for just getting right down to a straightforward solution to very sophisticated programs that apply some of the most challenging solving rules. This captures the whole world of Sudoku."

   Jay Cutts (Tijeras, New Mexico, USA).
Sudoku-Help+ Screen Shot of the unsolved Puzzle No 60, where Elimination Grid entries automatically update the Work Grid.
Sudoku-Help+ ScreenShot
Sudoku-Help+Solver Screen Shot of Puzzle No 60
(solved to the point where the XY-Zap Rule does an elimination that unlocks the puzzle.
Note also the new feature to highlight the last elimination done - a great way to see how the Solver did what it did.)
Sudoku-Help+Solver ScreenShot
Sudoku-Help-Plus as an aide to Sudoku puzzle construction
The puzzles in Sudoku-Help-Plus were crafted using Sudoku-Help-Plus itself as an aide. Here's how:

Plug a few values into the Sudoku-Help+ worksheet in a nice symmetric pattern.
To maintain 180o rotational symmetry for every given value placed in a cell at (x,y) there must also be a given in the cell at (10-x, 10-y). Whilst such symmetry is no more essential to the construction of a valid Sudoku puzzle, than it is to the placement of blanks in a crossword puzzle, asymmetric Sudoku puzzles look just as ugly as asymmetric crosswords.

Copy what you have to the Sudoku-Help+Solver worksheet and see how much of it can be solved by clicking the Rules buttons.

If it blows up, go back and change a few obvious culprits and try again.
If it gets stuck in a loop, leaves a cell without a value or places the same value twice in the same Constraint Region, you may have to chuck in the whole design and start again. Typically though you will have made some progress and will have a significantly reduced possibility set for the rest of the puzzle.

Go back to the Sudoku-Help+ worksheet, plug in a few more values and try again.

Repeat this process until you have a single solution valid Sudoku puzzle.

Then begins the process of peeling away givens, and then checking that the puzzle is still solvable
and perhaps in the process turning a lower Class puzzle into a higher Class one.

Use the Sudoku-Help+Solver to find the optimum path to the solution. This will then give the puzzle its SHD Rating.

Finally use the various value conversion and puzzle transformation buttons in Sudoku-Help+ to try to make the puzzle show the SHD Rating from within.

Then the puzzle will need to be retested through the Solver to check that the optimum path to the solution, still shows the same SHD Rating.
As a result of the transformations cells &/or values for some Rules may be processed in a different order requiring less iterations and thereby resulting in a different SHD Rating, where the puzzle will require further manipulative work.