As Ben said, not all black cell patterns admit an X solution, so I removed one black cell from the Elf's pattern.

Here are 2 X puzzles. The first one is M rated. The second one is for those who like a harder challenge.

is.gd/Elf_474_X_M

is.gd/Elf_474_X


Are there any other Elfs out there ?

Very good challenge, thanks. Good use of X-restrictions, until the end.

Still looking cool. Seems to be quite a challenge, even though I started with the M today.

Thanks a lot @Leren and Ben :-)

Here is a puzzle using The Elf's pattern:

is.gd/The_Elf_474_M

No chain needed

Thankjs; a nice Setti and x-wings puzzle.

I enjoyed it, nice x-wingfestival.

Don't forget to post an idea for a puzzle if you want your
name on it. I'm sure there are lots of puzzle Elfs out there :)

Hi Leren, i got "my own" puzzle already last year from you, but i think it's a very nice idea, indeed :)
Over the last few years i had many Hours of fun with your puzzles, so... thank you so much <3

Hi Leren, the puzzle Elf has got one more. ^^

Stay Tuned:

000000000
000010000
000001100
000010010
000000010
000010000
001100000
010010000
001100000

Perhaps ther are even some puzzle gnomes, trolls or wizards, who knows?

@ Elf

Is this a standard or X variant, or both ?

I only do the black cell patterns, but I like X-es (sorry, forgot to specify).

But feel free to make a standard from it as well if you like.

I don't think there is any possible x-str8ts puzzle with that pattern.

Since I have no idea how those puzzles are created, that may well be possible. Are there some guidelines (I can think of: symmetrical with rather free diagonals)?

That's why I wote last week: feel free to modify the pattern as much as needed. It's more like brainstorming input, intended to give new ideas, even if the original input isn't recognizable afterwards. ;-)

I can't provide any guidelines. A lot of patterns don't have an X solutions.

Your pattern has a lot of non-X solutions. I'll try and put one together, though for me it's quite manual to create a new puzzle. Not like Klaus, who I think can do it with one click.

The Elf,

I've built a puzzle in less time than it usually takes me. I hope you like it.

@ The Elf

I'm not much of a mathematician, so I can't give you a dissertation on what black cell patterns can't give rise to an X puzzle, but common sense tells me a bad X pattern is over-constrained in some sense, so if you remove one black cell, or even move it, it usually fixes the problem.

In the same vein I've always wondered why the knight jump gap between black cells produces so many great puzzles. Hone discovered that, so maybe he can enlighten us mere mortals :)

is.gd/Leren_474_M

quick exercise

thanks Leren, a nice moderate one

Thanks, a nice quickie.

is.gd/Leren_474

One tiny SI, rest is standard tools, though not too trivial. Good level of difficulty. thx

Didn't find something "tiny" after 14 solved cells, and switched to a chain.

@jgrab: I found a really tiny contradiction thing starting from A8, call it SI or chain (is there any difference?)

@jgrab: both possibilities in B2 lead to a certain conclusion, in fact it has overall the same result as kolumbus' contradiction.
Though… SI was the wrong word i used.

always a pleasure to be able to do everything just in your head...

This time weekly puzzle even for me was easy. Setti's rule indeed demonstrate how powerful it is. Extreme puzzles can be a bit more difficult.

Checking with the solver, indeed only one setti is required.