Feedback and Questions

I sometimes use the Windoku Solver to evaluate windokus. I have one (from e-sudoku.fr/windoku.php, number J3981) which I suspect has no solution. Windoku solver says "Or it has multiple solutions (check with [Solution Count])." But there doesn't seem to be a "solution count" button on the "windoku solver". I tried "Solve Path", and I had
"Solver by Andrew Stuart, version 2.30, 23-Apr-2023
LOAD PUZZLE
Clues: 19
Final Score: 0
Grade: Unknown"
It shows 18 steps, but I'm not sure what this means. Does "Final score: 0" mean there is no solution? Or what is the "Solution", which appears to show the numbers that the solver is able to find, plus the original clues, of couse.
Yours,
-- Owen

Hi Andrew,
I can´t open the German website any more - there ist alway Error 404.
So i´m missing one str8ts a day (the second one of the classical player) and nearly even worse: I can´t post any solution times or contact my "str8ts-community"
As someone (whose name should not be used) once said: very sad!
I hope the problem can be solves soon.
Greetings from Germany
str8ts

Many thanks for your Killer Sudoku Solver. I have been doing them for years and soon realised my limitations - can do Saturday Guardian and Observer but maybe require 2 or 3 shots at it. I was really stuck on 9/4/23 Observer puzzle - I had 4 attempts and none worked. Setting it up here was really easy - and you solved it - absolutely brilliant. I now have to work out how I went wrong - and you have given me a great start. HS.

The algorithm of the solver displays the first solution it found at a step. In my point of view, it should be interesting to know the other possible solution. Because for example, sometimes i found an AIC and when i compare with the solver, the algorithm found another AIC.
Thanks for this very good site.
Kader

Hi Andrew.
Have been using the Daily Sudoku iPad player for a long time, and I find it the perfect form factor. The on-screen keyboard doesn’t come up to obscure large parts of the board, and the ‘Check’ button is so incredibly handy.
So why are you threatening to retire it??? Please don’t!

Hello, great site you have here.
I came here to get some informations about the Setti-rule of Str8ts. Your article helped me a lot to understand it, but I don't see it exactly in your example with "Extreme number 31".
You say, that you are sure, that in every column there has to be a six. But column 9 would work without a 6 right?
Maybe I don't see it but this confuses me.
Anyway, thanks for all the hints and tips on this site!!!

This is an "extreme" puzzle, created by my generator, solved in 51 steps by the solver, employing tools: Alternating Inference Chains (10 times), Hidden Unique Rectangles (3 times),Aligned Pair exclusion (twice) plus Digit Forcing Chain, X-Cycle, WXYZ Wing. When I try to disable the latter two (to see if the puzzle remains solvable anyway) - the disable does not seem to take and I get the same 51 step solution path, employing those tools in the same steps.
Did I miss something?

The daily of 2023-03-18, difficulty 5/6, was an entertaining puzzle. First, I made a dum mistke but was able to back out of it a dozen moves after the fact, and you know how frustrating and then satisfying that is. Second, after solving down to confetti, all little numbers, I soon recognized a potential ambiguity spanning 9 cells, and all I had to do was avoid it to solve out quickly, and you know how satisfying it is to apply an abstract meta rule. SudokuGuy on youtube refers to this concept as "Danger", and he's quite entertaining in a Mr. Rogers sorta way, so which see. Actually, the cleanest way of looking at a Sudoku puzzle is that what we're actually doing is proving, by example, that the clues specify a single populated Sudoku board. Usually, the steps are cell-wise elimination, but "Danger" is puzzle-wise elimination. Whatever ingredients went into this puzzle, it came out yummy, challenging but not tedious, looking forward to more like it. Thanks!

Thank you. What an enormous amount of work you have done!

In Safari, the solve path window never appears for me. Works fine in Chrome.