Super fiendish Sudoku puzzle ...

[A580Hojas]

Anyone fancy giving me a clue on this? You can see where I've put two 3s in - but now have been stumped for days!

Any suggestions very gratefully received .

I’m addicted to them!

In the middle box, you can only have a 5 in the top row. That means in the middle right hand box, the five must go on the 2nd row, Where there's only one space.

Have you tried Suguru? I’m also addicted to them as well!

dkmgames.com/Suguru/

Ignore that, I'm wrong

It’s so hard @A580Hojas!

Your 3s might be wrong! You can see where else they could possibly fit in those boxes. Never guess!

This is what I do with hard ones: print off two copies and keep one clean for 'absolute definites'. Use the other one to put in tiny writing any possibilities and use this for eliminating. I erase any numbers that are definitely wrong as I go along.

Still often can't do the really tough ones!!

Oh, sorry OP. Looks like they're right!!

@gokartdillydilly

Your 3s might be wrong! You can see where else they could possibly fit in those boxes. Never guess!

This is what I do with hard ones: print off two copies and keep one clean for 'absolute definites'. Use the other one to put in tiny writing any possibilities and use this for eliminating. I erase any numbers that are definitely wrong as I go along.

Still often can't do the really tough ones!!

The more you do them the easier they are.

I started doing them years ago on a regular long train journey and at first I was often stumped. Then one day a light came on in my brain and I can now do them fairly quickly.

I love puzzles.

Sorry again OP, your 3s could be wrong!!

If the 3s are right (I haven't checked) then middle row right hand box, top right hand square is a 5.

Any use?

@hivemindneeded

If the 3s are right (I haven't checked) then middle row right hand box, top right hand square is a 5.

Any use?

Is the middle square of that box not also possibly a 5?

@gokartdillydilly

Sorry again OP, your 3s could be wrong!!

I think the 3s are correct.

Your 3s are correct. : )

Pencil the maybe's in v small writing, so if a 7 can only go in two boxes in a square, pencil them in. Keep on doing that all over. Eventually you will have some that work themselves out for you.

I always start mine in the bottom right hand corner by the way, and do the verticals first.

Agree, the threes are correct 👍

The 3s are right because [middle-left] 3 is the only thing that can go in the central box.

With the more fiendish puzzles I find I often end up tiny-writing two, three or even four numbers in each empty square. Eventually after a very long process you suddenly realise that eg one of the columns has four boxes that all say 1378, which means that you can cross out 1, 3, 7 and 8 in all its other boxes. Then one of the rows now has two boxes that say 49 which means you can cross out 4 and 9 in its other boxes. Then one of the 9-boxes now has two boxes that say 67 which means that the other empty one has to be 5.... and suddenly you've cracked it.

How are the 3s correct?! The 3 in the top left-hand box could be in any of the squares in the top line, therefore you don't know where to put the 3 in the next cell of 9.

Hasn't Shapiro solved it? 🤔

Ah yes @merryhouse, I see that now

@Shapiro

I’m addicted to them!

How is giving the full solution helping the OP to learn how to solve it?

@A580Hojas without giving you the full answer, here's your grid with all the possibilities marked on it.

Hopefully that will help you break the next bit! (As long as you can read it, of course!)

Sorry, I went off and cleaned the bathroom.

Thanks for all the input. I was really just looking for one more clue, so have scrolled past Shapiro's post.

I hate doing that thing where you pencil in the possibilities! So messy. I will keep plugging away unless anyone has had a moment of entlightenment?

I think with the hard ones it's really difficult without doing that! (Or it is for me, anyway)

Anyway - tip - you're looking for hidden triples

@merryhouse

The 3s are right because [middle-left] 3 is the only thing that can go in the central box.

With the more fiendish puzzles I find I often end up tiny-writing two, three or even four numbers in each empty square. Eventually after a very long process you suddenly realise that eg one of the columns has four boxes that all say 1378, which means that you can cross out 1, 3, 7 and 8 in all its other boxes. Then one of the rows now has two boxes that say 49 which means you can cross out 4 and 9 in its other boxes. Then one of the 9-boxes now has two boxes that say 67 which means that the other empty one has to be 5.... and suddenly you've cracked it.

This has blown my mind. I always get completely stuck unless there is an obvious box with only one possible answer in it!!!

I still don't understand why the 3 in the top left box is right. What's a hidden triple?