Sudoku solving strategy

Question

I started solving the puzzle below and I got stuck at this point. I don't know how to continue solving this puzzle except using try and error. Does anyone know of a strategy to solve it?

Hi. Here in a similar question I've posted all Sudoku solving strategies. I'm sure one or multiple of these solving strategies are helpful for your Sudoku. — Kevin Cruijssen, Aug 12 '16 at 07:54
@Bilal I've looked briefly at it and I think that unless you use brute force it can be solved further. — rhsquared, Aug 12 '16 at 08:25
Try reading about the XY-wing. It should help you to eliminate a few possibilities which will allow you to go on to solve the whole puzzle. I'll post it in a spoiler in an answer. — Shuri2060, Aug 12 '16 at 10:18
@bilal so u tell me the solution what I'd given, was it wrong? — , Aug 12 '16 at 13:41
@Stubborn as long as the puzzle in the image which bilal has given us has a solution (which it definitely does) then no mistakes have been made, and it is a valid sudoku puzzle. What you have done is unacceptable which was to replace numbers with your own - which means you must have swapped out at least one printed number. — Shuri2060, Aug 12 '16 at 14:04
Man just read above comment made by Bilal only , he himself is saying that he hasn't saved the original game. — , Aug 12 '16 at 14:06
@Stubborn: Question Asker was right. you can't replace numbers given in the puzzle because the are true — MBS, Aug 12 '16 at 14:08

Shuri2060 · Accepted Answer · 2016-08-12T10:50:24.770

First of all, if you decide to use a sudoku solver online to assist you (I recommend this one as it shows you the steps to solve it as well as having other pages explaining many sudoku solving techniques), here's your sudoku which you can just copy and paste:

792538641154000837368471295815249376647153982239867514083010009006080103001300008

I've already suggested reading up on the XY-wing technique in the comments as it will help you proceed onto the next step in this sudoku (in this case, more specifically, the Y wing). I also recommend writing all possibilities into the cells if you're really stuck as it can help you spot these techniques easier (although as you become a better solver, being able to spot them without doing so saves time).

If you still can't do it, I've included how it is used in the spoiler below:

(I've used the solver recommended above to make these screenshots)

Here is the sudoku with all of the possibilities written in:

Here is the Y-wing:

The logic:

J2: 2 $\implies$ H2: 7 and J5: 9 $\implies$ no possibilities in H4.

H6: 2 $\implies$ H2: 7 and J5: 9 $\implies$ no possibilities in H4.

Therefore, neither J2 nor H6 can be a 2, eliminating those possibilities from the cells. You can now fill in J2 and continue to solve the puzzle.

thank you. I wrote all the possibilities and try to solve it but I didn't understand the x-y wing until you explain it — MBS, Aug 12 '16 at 11:39

Sudoku solving strategy

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