Need help or a clue in my super fiendish sudoku puzzle please

[LindorDoubleChoc]

Been stuck on this one for days! Has anyone got a hint they can give me? I'm going to be VV embarrassed if it turns out to be something obvious 🤣

OK I'm getting in a pickle!

BIWI (at 16.30) "Row 5, column 7 is a 3"
Lindor (at 16.56) "at the moment I can't see why row 5 column 7 is a 3. The 3 could also go in column 9"
BIWI (at 17.01) "It's not 3, it's 7"
BIWI (at 17.04) "... and yes, 3 is in column 9"

@NowNumber5 - not really! Can you explain how you could be certain of the position of the 5 and 6 in that row? Then I'm sure I'll get going. Thank you .

Row 5 Column 7 is 7 (to the left of the 1)

Row 5, column 7 is a 7 (sorry!)
Row 5, column 9 is a 3

Oh bloody hell! I need a non-alcoholic drink (Dry January grrrrrrr).

OK - about to go out now, but here's a bit more:

Top left-hand box, column 1 is 4, 5, 7

Middle box, right-hand side, is

5 2 8 (i.e. row 4)
7 1 3 (i.e. row 5)
6 4 9 (i.e. row 6)

I think the OP doesn't necessarily just want the answers but how you worked out any one square in particular from her starting point, which will help work out how to continue.

Thank you @boatyroo, yes I'd love a solving clue rather than an answer.

I can't see how knowing that the first 3 numbers in column 1 being 4, 5 and 7 is a solid clue. Obviously I know they are, I mean it's obvious! I've known that for days. I need to go a few steps further.

But at the moment, as solved so far, the 7 in that square could also go in row 4. And in that row, the 7 could go in column 3, 5 or 7.

I think I'm missing some special knack or technique for advanced sudoku!

Ask ChatGPT ?

E2A: I did 😀

The puzzle provided appears to have inconsistencies or missing information, making it unsolvable with standard Sudoku rules. Could you verify the puzzle's numbers or provide additional details? If you suspect errors, I can re-evaluate or help clarify further.

I am also trying from the same point so will let you know if I work anything out.
So far agree, yes row 5 column 7 probably is 7, but haven't worked that out with logic so don't want to just take someone saying that and fill in from there!

For me it’s because of the position of the 5 in the grids above and below. A 5 would need to be in that middle column.

Last row 4th number is a 2

At this point it could be in row 4 or 6 though?

A lot of the time it's which number won't fit rather than what will.

This goes step by step and helps to explain:
https://www.sudoku9x9.com/howtosolve/

Rows 5 and 9 both have 4 in only either column 3 or 5, so 4s can't appear in those columns in any other row.
This helped me eliminate the 4 in row 1 column 5, and then meant row 3 column 4 must be a 4.

From there I was able to continue on and finish it.

Rows 5 and 9 both have 4 in only either column 3 or 5

Row 9 can have 4 in column 3, 4 or 5. How have you discounted column 4?

Thinking back now but I think it was because there were 2 cells in that column that had only 7 or 4 so I eliminated it as an option in the other cells of the column

The step by step does show that part too, but I had already got to that point before inputting

No it isn't

There is a 7 in the top right hand box column 8 which means that the bottom right hand box must have a 7 in column 9, so the 7 in the middle right hand box must go in row 5 column 7.

I can only do them when I fill in all the notes, I thought you you’d done that and were still stuck? I want to see the version you’ve done with the pencil notes. I only do the online ones these days so you can do the notes really easily.

@SerendipityJane But I HAVE solved it! So there isn't missing information.

I tend not to need to fill in the pencil marks, I can remember the options.

But I've done it now. No further forward. Every square has at least two possible numbers and there are none of those in the same row, square or column which could make any of the other possible numbers definite - iyswim.

@LindorDoubleChoc really recommend inputting your numbers here and it will explain how the next number can be determined more clearly than I probably explained!
https://www.sudoku9x9.com/howtosolve/

"For me it’s because of the position of the 5 in the grids above and below. A 5 would need to be in that middle column."

Agree, but the 5 could also go in row 4 in the middle column in that grid @NotApplePie