It's raining...

is.gd/morl_518_2

Opens nicely with a Setti interaction.

Thanks, morl, for this beauty. I love setti considerations.

Really nice chainless puzzle! With A5 being the cherry on the cake or umbrella :)

I did it with 3 fishes, CE, 1 normal Setti, no special considerations. Thanks, morl

is.gd/Leren_518_X2

Again a skewed fishes festival, staight ahead, thanx!

Very delicious skewed fish soup. Thanks Leren!

These next 2 puzzles should be more relaxing. No chains, SI's, UR's or fancy Setti arguments. Just standard moves.

is.gd/Leren_518_2

Thanks. A nice Setti cascade.

Nice and quick. A little setti analysis did it. Thanks!

I would like to draw your attention to the new 'every 2 days' of Andrew. Difficult, but solvable (for me with HC).

@pax:I found an interesting two cell UR: J9=89 would lead to a non-unique solution with H9 --> J9=7.
After setti 8, the remaining 17 cells needed a HC as well. Mine started with D6=1, which conflicts after 5 cells in G5. Did you find a shorter HC?

Apologize: My last comment was regarding Andrew's weekly. Haven't even looked at the 'every two days'

On the 'every two days', I also found it difficult and chained. A lot. The first big chain was a careful game of high/low in rows A,D,E and columns 1,4,9. Settis also help and there is an optional UR.

I had to guess in two positions: A1 and G6.
Pls. open forum.str8ts.de and look at my solution.

BUG variation of my puzzle from last week.

is.gd/morl518_1

Easier than last week. I overlooked/forgot what BUG stands for?

Thanks. To reach the BUG I needed setti and a SI in the middle.
Here is a reference for the BUG strategy : www -dot- sudokuwiki -dot- org/BUG
it stands for "Bivalue Universal Graveyard" and works on the unicity principle. As far as I understand, to apply it in str8ts you need to know all required/excluded digits in all compartments.

is.gd/Leren_518_X

Like many of your puzzles, but unlike Andrew's, I don't get very far.

What is the key to these puzzles with so few clues? Besides simple logic, settis, fishes and URs.

In case you don't know, this is an X puzzle. The diagonals have compartments just like in rows and columns. In addition, many moves peculiar to X puzzles have been discovered. There is a big list of them in week 500.

Another master piece, I needed x-wings, settis, and 2 short head chains. But probably more elegant ways possible :).

Quite hard, took me 90 min. The skewed wings were not enough.

A hard nut – besides common tools I used lots of skewed wings, a short head chain to solve J1 and some Setti considerations (1/2/5/9) which finally solve. Thank you Leren!

Same here, quite hard. Used skewed x-wings, some setti considerations with implications on r5 & cF, then some more skewed x-wings. At 21 solved cells I used another setti consideration on 9 in combination with setti 5 to solve, but I'm not quite convinced that my setti considerations were chainfree (some might at least call them street interactiony... ;).

Hard indeed. With skewed wings and fishes to 21 solved cells. Then after milkyjoe's hint an SI-setti-analysis of setti 9 which solved. Thanks, milkyjoe for the hint, and thanks, Leren, for this tough beast!

Phew, tough indeed.
First time I used setti considerations to fix the high/low in col.5, then got stuck until I read milkyjoe's comment with BP's precision. But I got a mistake afterwards. Second time, to fix that high/low I used a small headchain on the two possible positions of 6 in row A.
There are several skewed X-wings, a skewed swordfish on the left, and a skewed almost jellyfish on the right. That almost jellyfish still allows several eliminations in cols 6,7,9 because those positions would exclude the endofin (by Leren's vocabulary). Unfortunately those exclusions did not make the puzzle progress.
Thanks Leren, milkyjoe & BP.

is.gd/Leren_518

Thank you Leren, I used a very short head chain in between. The rest is careful elimination, often based on setties.

So many mutual dependencies, but got along somehow with very CE (almost undistinguishable from head chains).

CE, settis and a chain in the end. Solved in 27 min, very nice one.

CE, settis and several SIs. Thanks

Settis, singles, wings + 1 SI. Thanks, Leren, very enjoyable.

Reserved for discussion of Andrew's puzzle. morl will love it :)

In the end I needed a short head chain, is there a better way?
WCable.

Yes, I like this one very much. It can be solved using an XY-loop in DH67 and an XY-Chain in GH4EH7.

in those little-number-of-cells-with-little-number-of-candidates-but-still-a-chain-is-needed-situations, that arise from time to time, i find it always challenging and fun to spot the chain with the minimum number of cells involved.

here the best i can get is 6 cells.

OK, now I see a shorter chain: One of B56 is 1, which means one of D6 and G5 is 3. Hence D5<>3.

thats 5 cells, fine.

i think this pattern could be generalized to a common rule (the Sudoku guys surely have done this), so this solution can be seen as chainless.

Ben has previously dubbed this move a Confined Spaces SI.

After easy steps of standard tools I use swordfish on 8 and XY wing on 8. As result I get column 8 without 8 and I could continue solving. At the final stage I create simple chain (I can say head chain) to find solution of B6. The rest was trivial.

I am sorry! In my comment is mistake. Of course not XY wing but X wing.

@morl:
Splashing, a peculiar situation in D5, where 3 is mobbed out.