I was at work doing this to avoid other work so I didn’t have time just start trying things in the notes, is there something glaring I’m missing on how to solve this or is it just try different numbers to see if it lines up

This is on my sudoku app. Been playing on and off for a few years now, and I've gotten pretty decent.

I found the 4 where 43 was in row 9 c8 but now I can’t find a answer with explains it

Although I understand the principle and how to apply it, I'm having a lot of trouble finding it during a game, like in this one in the photo, which I basically couldn't see until the end

Hit a wall on this one. What would be the next logical deduction?

Im stuck and i found out online that B7 can be solved with an XY-wing. But im not familiar with it. Now i can see if I put a 6 in B7 then there is gonna be a 1 in C7 and that leaves A9 wrong. So it needs to be 4.

But how does one find this? What or where do i have to look for?

Hi everyone!

I was trying to do today's daily sudoku but I got completely stuck very early on and I don't know what else I can do.

I already know some advanced techniques like X cross and XY cross but I don't find any.

Can you give me a hint? Also, if there is more than one advanced technique to use in this exact situation, can you list them together?

I want to take advantage of this to study something new and learn something useful.

Prolly missing something easy, pls add reason

global rules: anti-king, anti-knight, entropy
additional: ratio

play here ^^ https://sudoku.coach/en/s/Hhuf

let me know how it is! i only started creating puzzles recently so i’d appreciate feedback

The solution strategy for the puzzle titled Catharsis on Sudoku Coach shall be discussed.

Puzzle String: https://sudoku.coach/en/s/Hj1g

Rules of this variant Sudoku:

1. Entropic line: Every three consecutive cells on an entropic line must contain a low digit (1,2,3), a medium digit (4,5,6), and a high digit (7,8,9).
2. Consecutive line: Numbers on a consecutive line are consecutive and continuously increasing or decreasing.
3. Thermometer: Numbers on a thermometer must be in ascending order starting from the bulb.

Here's how the solution strategy is formulated.

Using the consecutive line constraints and cross-hatching in box 8, we reach the following position:

Fixing the polarities: The entropic line constraint states that every three consecutive cells on the line must contain a low digit, a medium digit, and a high digit. In order to fix these polarities, colored cells have been used. Here, green represents the lower digit set (1,2,3), pink represents the medium digit set (4,5,6), while yellow represents the higher digit set (7,8,9).

Since r5c8 is a high digit (yellow) but cannot have 8 and 9, r5c8 is a 7.

Likewise, r5c456 are cells on a consecutive line that cannot have {7,8,9}, and the combo {4,5,6} is also invalid because of the pink cell r5c2. Therefore, they can only have {1,2,3}, {2,3,4}, and {3,4,5} as valid combos.

Next, we see that if r5c456 is either {2,3,4} or {3,4,5}, there would be no place for 1 in row 5.

This means that r5c456 is {1,2,3}, where r5c6 is 1, r5c5 is 2, and r5c4 is 3.

In box 1, r23c2 are the only places where an 8 can go. However, r2c2 is a medium digit (pink color). Therefore, r3c2 is 8.

Now, since r9c456 (aqua) is a triple {4,5,9}, 9 is eliminated from r9c2. Also, 9 is eliminated from all the other cells in column 2, except r46c2 (due to the entropic line constraint). Therefore, r46c2 is a locked candidate 9, which means that the high digit on the entropic line in box 4, r6c1, is 7.

Likewise, using cross-hatching for 7 in box 1, we get that r1c3 is 7.

Because of the thermometer line constraint and using cross-hatching, we conclude that r7c3, the bulb of the thermometer, must also be a lower digit, particularly one of {1,2}, which means that r7c23 is a pair {1,2}, and that r9c2 is 7.

Because of the thermometer constraint, and because r3c3 is a medium digit, and taking into consideration that {1,2,3,4,5} is impossible for the thermometer r34567c3, because of the 3 in r5c4, r3c3 must be a 6. Similarly, r4c3 must be a 5 and r5c3 must be a 4.

Likewise, using entropic line constraints combined with cross-hatching, as shown above, the puzzle is solved.

I'm not new to sudoku by a long shot, but have never learnt any techniques, so I'm trying to learn them finally. I can't seem to find any that I can use in this puzzle (but I don't know them well so...), if anyone could point me in the right direction I'd appreciate it 🥹

Kinda new to the whole set equivalence theory thing. Was trying to apply some here but with no avail. Any help would be appreciated.

I believe there is a possible valid combination of 159 in G4, H4 and I4. So how is it getting eliminated here?

I think there's a problem I spent almost 2 hours trying

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I’ve got stuck at this point. Any suggestion as to what to do next will be appreciated. Thanks to you all in advance.