SudokuSolver Forum

Hi folks!

For quite some time there have been no feedback what so ever regarding the Regular Clueless Explosion puzzles. From the number of views it looks like there are some 30+ people that try the puzzles. What I would like to know is:

1) Are anybody solving the Novice level puzzles?
If by the end of November no one has said that they actually try the Novice level puzzles, I will stop making them.

2) Are anybody trying the Master level puzzles?

3) Any wishes or anything I should do differently?
For instance a difficulty level between Apprentice and Master.

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I try all levels but can't do the harder ones without process of elimination logic at some point. I solve them on paper to get away from screens as much as possible. The simplest ones are the quickest way to get a solution for the harder puzzles. Is there somewhere where the solutions are posted? I haven't found it yet.

You can import the code string below the puzzle into a solver such as SudokuSolver or JSudoku (probably the only ones that can handle Clueless Specials, Clueless Explosions, AND Samurai) and let the program print a solution for you.

jay_boris,
Thanks for your feedback.

As enxio27 wrote you can easily obtain the correct solution by using SudokuSolver or JSudoku. Hence I have not bothered to include the solution. If anyone would like to have the solution included as hidden text, please let me know and please specify the format you prefer.

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I am solving the easiest master-level puzzle you post. I've adapted to dealing with skyscrapers and two-string kites. I rarely can find an xy-wing unaided, but I'm trying to learn. Uniqueness tests are easy to spot, but I still consider it cheating so I avoid using them unless it you list it as a required technique.

Finned x-wings and any sort of chain are still beyond me. (Regular x-wings are of course straightforward, and really just an apprentice-level technique in my opinion.)

Generally the apprentice-level puzzles are a bit too easy for me, though if the required techniques for the master-level look too difficult, I will do the apprentice instead.

I've fallen several weeks behind -- next on my list are Explosion #19 and Special #20. Thus I haven't been posting recently -- but do still quite appreciate your efforts!

Hi jsmif,

Thanks for your feedback. Good to hear from you again.

Glad to hear that you still enjoy many of the Master level puzzles. I try to vary the techniques required, both for variation and for encouraging people to learn new techniques. When unusual techniques are required, I will try to post a mini-mini Walkthrough. If now several people come forward and say that they would like to see an overweight of Skyscrapers and Two-String kites in the Master level puzzles, that can probably be arranged.

When I started creating puzzles and had no experience with this, I always just stated all the techniques JSudoku listed. For the Master level puzzles I now examine the required techniques thoroughly, and now hopefully only list those that are absolutely necessary. So if JSudoku lists 4-6 techniques, I will hopefully list only those 1-3 that are actually required.

I also try to create Master level puzzles where at least one of the advanced techniques are required early on, making it more difficult to find


Do not underestimate the Uniqueness tests:

1. In a puzzle with overlapping nonets a Uniqueness test should only be applied when you are 100% sure that the cells involved cannot be influenced by the overlapping nonets. Otherwise you may get an invalid solution. I have personal experience here.
2. AFAIK a Uniqueness test in NEVER required. It can always be substituted with one or more other techniques, but normally several other techniques often involving Chains are required. So the Uniqueness test is almost always the easy shortcut. Regular Samurai #17C is a good example.

Finned fish is not really that difficult. I think the main problem is finding some good explanations on how to find them. Here is what I do:

1. Find a set of row or columns that represents a basic fish but has one or more extra cells, the so called fin(s).
2. Mark all pencil values that can be eliminated by the basic fish alone.
3. Mark all pencil values that all fins can see.
4. All pencil values that can be eliminated by the basic fish alone and that are also seen by all fins can be eliminated.

Chains are notoriously difficult. The "easiest" chain type is the XY-Chain where all cells involved contain 2 candidates only.
As a training exercise here a challenging vanilla sudoku which requires a single advanced technique, which is an XY-Chain with 4 links:



690000304001078900000000000250001000080000090000400038000000000002150600407000015



Here the chain:

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