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 .

This is the link I gave earlier. Scroll down to the advice on hidden triples. I agree with what they say in the link & (sorry) not with what the other poster here is saying about triples.

www.angusj.com/sudoku/hints.php#:~:text

I can only reiterate what I said earlier as to how I solved it.

I am referring to the 9-square boxes as
ABC
DEF
GHI
and the individual squares within each box as
abc
def
ghi

Once you have the various options in tiny-writing, as given by a couple of previous posters

imagine that square Be is 6
-then Eh must be 9, so He is 4, which leaves Eb as 5
-but if Eh is 9 then Ef must be 8 so Ed must be 5

Ed and Eb cannot both be 5 so our initial assumption - that Be is 6 - must be incorrect. Therefore Be must be 5.

I think there wasn't anything particularly complex after that.

I did this last night/ this morning and got the same 3s as you (although I needed tiny writing to get to that point!) The only way I managed to complete it was trial and error on a cell with only 2 options and lightly pencilling in one of those until it didn't work so it then had to be the other. I couldn't see any hidden triples or similar so will keep watching this thread to see if there's a "proper" way to solve this other than trial and error.

I think we need another one @A580Hojas so we can practice the triples thing!

I went wrong on this twice, but I've completed today's Times Jumbo Cryptic, so swings & roundabouts...

Try yesterday's Observer one @SmolCat:

www.theguardian.com/lifeandstyle/2022/jan/23/observer-sudoku

Thanks @BIWI I made the mistake of opening the fiendish one and have been doing it for hours!

I really struggled with that Observer one yesterday, and cocked it up. Took me ages too.

So I printed another copy off this morning and did it really easily, in a quarter of the time. No idea why that was!

I only pencil in the 50/50 ones, using dots in a 3x3 pattern. That way I can write over them easily.
But I take a photocopy of anything more than medium difficulty.

I could do plenty of those on the OP’s photo but I haven’t tried to solve it.

Finished!
Apologies for the scrappy pen work…