Sysudoku Exocet

Advanced methods and approaches for solving Sudoku puzzles

Sysudoku Exocet

Postby David P Bird » Tue Apr 26, 2016 10:17 pm

On Andrew Stuart's Wikipedia site puzzle 190 in his series of <weekly unsolvable> puzzles has attracted the interest of a blogger <John Welch>. This puzzle contains a single JE2 pattern which converts into a double JE4 when the standard pattern eliminations are made and so provides a quick route to allowing a solution to be found using standard methods.

I fell on his blog last week as a result of a Google search where he announced he would cover the topic this week. Consequently I posted my solution to puzzle 190 on Andrew's site – just in case. (This week's unsolvable, number 197, also contains a JExocet for which I have also posted a solution.)

In this week's blog Welch references the JExocet Compendium thread, which pleases me, but then misinterprets the analysis given there, which doesn't. Perhaps I failed to be clear enough in my writing, but I don't feel too bad as it was his choice to remain a remote onlooker rather than a contributor here.

However, what Welch advocates in his own home-spun terminology may interest some readers. It seems to be a templating type system for finding base digits and target cells which could extend the scope of the Exocet (as opposed to the Junior Exocet) approach.

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Re: Sysudoku Exocet

Postby David P Bird » Tue May 31, 2016 8:34 pm

Update: John Welch has studied the defintion and proof of the JExocet patterns further and has modified his opinons somewhat.

However he takes the view that that a JE pattern recongnition check is equivalent to his trials to explore the effects of different base digit combinations and that creates a chasm between us. He seems also to consider that all the JE elimination rules stem from no more than a hypothesis which creates yet another chasm.

Nevertheless, some readers may feel more comfortable with his approach rather than having to follow the rigours of a JE pattern check (all is fair in love and how we solve Sudokus), so sorry chaps, move on - there's nothing to see here.

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Re: Sysudoku Exocet

Postby RichardGoodrich » Mon Nov 14, 2016 4:07 am

I am also sad John Welch won't participate in this forum. I interacted him with some, but he is very stubborn about his unusual notation which makes it difficult to interact with him. He is also starting to review Denis Bethier's "Hidden Logic of Sudoku" and it also seems DB has not been here in a while. I like both these guys and think they have a lot to contribute!
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Re: Sysudoku Exocet

Postby StrmCkr » Tue Dec 06, 2016 2:08 pm

I interacted him with some, but he is very stubborn about his unusual notation which makes it difficult to interact with him

you can say that again, I've also had a bunch of interactions with him, his notation tends to follow every extended connection which makes it difficult to follow what hes doing when his notation for everything is his own creation as well followed with a "name" of technique stuck to it that never exactly matches definitions.

we butted heads when he tore into my extension covering of wxyz-wings technique where i re-classed it as an als-xz definition to cover additional eliminations that where often overlooked from its original simplified definition, in the end he still refused to call it a wxyz wing and re-classed every xy,xyz,wxyz technique as a "bent almost naked " ie barn then tried to attribute the name to me as if i discovered it... err.

for me I'm more annoyed that he over reads or misses small details and writes gigantic blogs ripping said idea apart but completely misses the underpinnings that makes his entire post off kilter, trying to talk sense into him after that is like smashing my head into a wall.

some of his idea are interesting once i figured them out, but then again as far as i can tell he doesn't follow any hierarchy for solving and over extends everything, perhaps he readers enjoy his muddled approach.

he probably won't want to join the forums because his naming and data display's don't conform to anything we have been using for 15+ years.

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