A relaxing way to end the week. Blow up Hone's tank with a cannon :)


is.gd/Leren_505_Cannon

Nice! Develops step by step. Hi/lo decision on on F78 is quite easy, some CI, and Setti does the rest. 38 min, though.

Very nice! ...but it's simpler than that: After the high/low in column 7 and row F, there is a large wing and an x-wing, after which the puzzle collapses.

common tools did it, thanks Leren

is.gd/morl505

Thanks morl,

nice and relaxing with wings and small fishes.

Thanks. Wings/fishes only, not exceeding 3x3 patterns.

Thanks! Smooth with three 3-wings on three different digits in three different corners and one x-wing in between.

Like the others, thank you, morl!

is.gd/hone505_Tank

Develops very nicely with a lot of wings, a large as a starter. At 44 solved cells need a head chain to decide which of two possibilities in a column is the incorrect one.

Looks more troublesome than it is. Nice practice for wings and fishes, no chains needed. Thanks!

Thank you hone, nice!
I recap not using a big fish in the beginning, but probably the same HC towards the end.

is.gd/Leren_505_X

Tough, but good. Needed whole toolbox, including two very skewed xwings (aka Finned Franken (Skewed) X Wings) and one SI. Thanks, Leren!

can't see anything of that kind at 33 solved cells...

@Jan: Not sure about the number of solved cells but some of our crucial steps were:
a skewed swordfish on 6,
a very skewed xwing on 9 to remove 9 from C7,
SI to remove 9 from H8 (H8=9 => ... => C7=B8=6),
a very skewed xwing to remove 8 from A5.

@BP: I believe I identified the skewed 3-wing on 6 - the \ diagonal and columns 3 and 4, correct?

But I can't see an X-cycle on 9, in particular because I still have (689) as candidates on the / diagonal and again three 9s on the other diagonal.

@Jan: The skewed swordfish on 6 is correct.
The skewed xwing: We had a pair of 9's in H78 and one in CJ9. Since H8 and J9 meet on \ there is an odd cycle: C7->H7->H8->J9->C9->C7.

Thanks, BP. But those X-cycles are chains to me, and this puzzle, though solveable, is a bit too chainy for me. However, I find it amazing and surpriing that one can build such a puzzle with only three clues!

@Jan: I can well understand that you consider the X-cycles chains. At first I didn't like them too much either. However, I am getting used to them and they are a really helpful tool for Leren's x-puzzles. If you are stuck just look out for pairs of the same digit, check whether two endpoints meet in the same row, column or diagonal and test whether they form a helpful odd cycle. I like that approach better than just randomly looking around for a helpful head chain.

Yes, that I can agree with!

is.gd/Leren_505

thnx - nice puzzle - no chain needed

Very nice, I used a short head chain. Thank you Leren!

hard one. no chain.

With the last 4 rows solved, I'm struggling to find a way without a chain. Any ideas?

@ bukabay

Look in the top left hand corner.

Very nice one. Just settis and CE. No chain needed.

I used a consideration based on setti 2 and the situation in row C, which solves E7 and with it the puzzle.

Can't see how Leren's hint helps...

Used SI on E7 to finish. Thanks, Leren!

@ Jan

There is a head chain/SI there that solves, but it's a bit early in the week for a spoiler. Maybe later in the week if you still can't find it.

Perhaps we are talking about the same thing here...we'll see later in the week. In any case, solving E7 is the issue.

@ Jan

At 25 solved cells the SI/head chain I used was :

B4 = 5 > B1 <> 5 => A1 = 7 => A4 = 6 => B4 <> 5

Thanks, Leren, but I don't grok that. I still have (24) in DE4, so I can't follow that last conclusion of yours, A4 = 6 => B4 <> 5. What am I missing?!

At 25 solved cells I have D12 = 98 and there is then a naked pair (24) in D79. Hopefully that will help your grokking.

Ah, thanks, can't understand how I missed that little elimination in A1 which solves D1 8-(...!

Reserved for discussion of Andrew's puzzle.

Nice and tricky, perfect difficulty level for me
Thank you Andrew

Really a very nice extreme. Starts off with an x-wing, then a BCA consideration followed by a setti, some singles and finally two x-wings. Column 4 gets all the attention.

I made a mistake in the first attempt. In the second attempt I tried to be very careful. In addition to the standard tools I used the analysis of possible combinations of str8ts in column 4 and row F. This made it possible to reduce the number of candidates (possible str8ts) and find all sure digits. I liked the puzzle, thank you Andrew!