Learn To Solve Diabolical/Extreme Sudoku - The XYZ Wing

We take a look at last Friday's Diabolical Sudoku from The Daily Telegraph. Nothing too hard until an XYZ wing appears - and this is a good chance to explain the difference between this and a Y-Wing!

[drakenskag]

Just ran into the xyz-wing in my latest puzzle. Thank God for this channel. I've been picking up sudoku (again) and I had never really delved too deeply into strategy before. Your channel has been helping me understand some truly difficult stuff for my brain to understand simply from a written explanation.

[LinXiaoChaun]

I prefer the (equivalent, arguably simpler) reasoning: an 8 in R2C3 is unacceptable, because assuming 8 in R2C3 leads to an illegal outcome, namely forcing a 3 in R3C2 and a 4 in R8C3, thereby eliminating all candidates (348) for R3C3. This reasoning would also apply to R1C3, if that cell were not already fixed. Just a different way of thinking about the XYZ wing.

[yzwrvbf]

I suspect that these "bent triples" were in some of my previous diabolicals, so I will definitely be looking for them in the future. It is much more elegant than my forcing chain method, which I use as a last resort.

[nathanvanduiven]

Love the bent triples, this is going to revolutionise completing my sudoku books.

[samuelking]

I know this is very late and unlikely to get a reply but at 4:26 how did you resolve that 4? I can’t see why you could rule it out of the top left corner of the grid, or the bottom two corners of its box.

[dmitry-ievdllz]

This sudoku can be solved using only basic and tough strategies.

[mrabadisa]

may i ask you please. How we can have the App you are using?

[ivandolinic]

At 4:27, how did you know that that particular cell ina first row has to be no 4?

[robertritchie]

What is the name of the program you are using?

[iLuvHardStyle]

This puzzle has way more numbers to begin with than what i just starter solving.. im stuck 😅

[shubhamkr]

this is not extreme... I'd call it hard.