X-Wings and the Rectangle Rule for Solving Medium to Hard Sudoku Puzzles

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2 жыл бұрын

Lesson #X-wing10: patterns appear often and can be used as a Sudoku solving strategy to eliminate candidates. This quick Sudoku lesson explains how to recognize the X-wing pattern, also known as the rectangle rule, and how to use it as a strategy to solve Medium and Hard level Sudoku puzzles. Keep practicing, and learn something new every day!
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Пікірлер: 85

@hilaydt Жыл бұрын

I've watched many other videos and read tutorials on how to do X wings and I never understood until I watched your breakdown. Thanks so much for the clear explanation!

@majaber1 Жыл бұрын

me too

@rameshramasamy21 11 ай бұрын

Me too

@leemelbourne-weaver4337 9 ай бұрын

ME too

@soniaperezcaceres3935 7 ай бұрын

Same!!!!

@RandomThingsEn 4 ай бұрын

SAME! the other tutorials didn't really mention the rows part

@rameshramasamy21 11 ай бұрын

Thank you for clearly explaning. I was not able to resolve a sudoku and didn't sleep for 5 days. Your video rescued me.

@jballenger9240 2 ай бұрын

The clearest explanation I’ve heard of the X-wing. Thank you m

@flynn1a 11 ай бұрын

I have watched several x wing videos and couldn’t get the gist of what they were saying. But you made it so simple and so obvious! Thank you!!!!

@StephenRahrig 3 ай бұрын

Why are you calling it a 2 x 2

@r.mcd2921 2 ай бұрын

Thank you - this was the first explanation that made sense to me.

@JonJacks Жыл бұрын

Okay wow! I've seen the X wing so many times and never thought there was a strategy. THANK. YOU.

@kalpanasarkar9331 Жыл бұрын

Best explanation of x wing I've come across so far

@martinaperez9594 10 ай бұрын

Such an useful trick! I'll implement it, thanks!

@Omoplata183 10 күн бұрын

I finally get it, thank you for this!!

@SmartHobbies 2 жыл бұрын

Great straightforward explanation of X-wings. I always found it interesting that 2x2 are called “wings” where 3x3, 4x4, etc. all are “fish”. I look forward to watching more of your content.

@LearnSomethingNewEveryDay 2 жыл бұрын

Thanks Smart Hobbies.....yes it is interesting how these are called exotic fish names.....thanks for your support, I appreciate it! Good luck with your channel, it looks interesting....I just subbed!

@faisalrezhaRakhman Жыл бұрын

Easy to understand, thanks alot.

@rajeshwarichauhan4257 9 ай бұрын

I had been trying to understand this pattern from many videos ...but u explained it so clearly...i got it in a minute..❤🌻

@LearnSomethingNewEveryDay 9 ай бұрын

Glad to hear that, thanks for the comment!

@ruatoomey9107 7 ай бұрын

Top class, thank you

@mattnorton3285 Жыл бұрын

Apologies if I'm missing an obvious implication, but for the part of the video from 1:26 to 1:34, why must the 2 in column 7 be the correct one? Why couldn't the 2 in column 8 be correct? (and same question for the 2 in column 9 in row C)

@fire285 Жыл бұрын

Hey, the square is the only option for these numbers. We know 2 must be present in column 4 and 7 and that all other options in column 4 and 7 cannot hold a two. As a generalized rule, if a square exists where either a row or column requires a number to be in the square then both the row and column require the numbers to be in the square.

@love4music25 4 ай бұрын

can you expand further? @@fire285 I still didnot get it

@hebum Ай бұрын

I was wondering about the same thing but if you look at the column 7 , 2 can be placed in only in the A or C rows for that column so we wouldn't even mark 8A or 9C as possibilities 🤦‍♂

@kskaliprasadkotagal6468 2 жыл бұрын

Thanks for sharing this idea of elimination

@claudegiguere8731 Жыл бұрын

straight to the point and excellent explanations 👍 Thanks a lot !!!

@muhammadzakyyahya1625 Жыл бұрын

I still don't understand the first example..

@yennisutedjo4173 Жыл бұрын

Nice explanation

@scorbett4370 2 жыл бұрын

Is this rectangle referred to as a 2 by 2 because it involves 2 Blocks AND 2 Rows AND 2 Columns? Thank you for the video.

@kenjohnson4645 10 ай бұрын

Would if be possible to get the name or link of the Sudoku program that you use in your tutorials as I wanted a program that would allow the user to take advantage of or have the ability to use a "Red X" or similar markings.

@aubreymaichi4600 Жыл бұрын

omg finally a vid that's easy for me to understand😢

@divermike8943 3 ай бұрын

Why do you say it is a 2x2 retangle? The first example with the 4s is three rows by four columns. So is the second example with the 2s. Does the size of the retangle even matter?

@DiederdirkDusty 22 күн бұрын

The size doesn't matter, only that 2 colomns/rows contain 4 cells where a candidate can go and form a x-pattern.

@hieutv.thebattlecats Жыл бұрын

very nice

@kevinklise7036 2 жыл бұрын

A good explanation. However, I need to ask for a couple points of clarification. If the particular number being used as the four corners of the rectangle (in this video, it was a "2"), then all the other 2's in that row can be eliminated. Does that include the 2's that are ONLY OUTSIDE the rectangle? Or can it include the 2's (if any) BETWEEN the four corners of the rectangle?

@eugenetswong Ай бұрын

Yes, between and outside. I remember it this way: it doesn't matter how you find the rectangle; eliminate all of them in the columns and rows, except the 4 corners.

@robertvolm3609 11 ай бұрын

So, does this mean that a "X" is always a 3 square by 4 square grid? Can it be 4 squares by 5 squares? Or anything different?

@robertnutt4944 2 жыл бұрын

Hi, how does this work in a 16 x 16 Sudoku? Any different?

@believeinaction 2 жыл бұрын

Love from India 🤩🤩🤩🔥🔥

@timothymarchant 11 ай бұрын

so what happens with the annotated number outside the rectangle but in the same box but it's in the middle/ For example if Cell B9 had a 2 candidate as well would that justify removing that candidate?

@brittanydrake7643 3 ай бұрын

I was wondering the same thing

@NightSovereign 4 ай бұрын

what does 2x2 stand for? And why is the rectangle 4x3 is called so?

@BillSmith-bd1yv 4 ай бұрын

Sorry, I don't understand why we would call an area of 4 squares by 3 a "2x2 rectangle" and if it really was 2x2 then wouldn't it be a square? Asking for clarification because I can see lots of potential candidate configurations, but they can't all be usable. Thanks in advance.

@epistemophiliac5334 9 ай бұрын

I don't understand why you can eliminate the 2s in A8 and C9. The solutions for 2 could easily be A4/C9 or A8/C4. Why does candidates forming a rectangle mean you can eliminate every other candidate in their rows?

@anonym6891 5 ай бұрын

In my opinion this explanation has errors.

@cineeleo 2 ай бұрын

Hi, late answer, but anyway: if you try any of your possible variants, A4/C9 or A8/C4, you can observe that in column 4 and in 7 there is no cell to put the 2. That's because in column 4 and 7, the 2 can be put only in A2/C7 or A7/C2. Hope this helps.

@royalbloodedmutt Ай бұрын

Finally an explanation that makes sense!!! Bless you.

@lindac6147 2 жыл бұрын

I’m confused . You state when referring to the first example ( ~3:00) with “2” that they are identified to be part of an x wing if the candidate only appears twice. However “2” appears three times on row A?

@groslou9997 Жыл бұрын

You have to think in columb

@groslou9997 Жыл бұрын

Column 7

@diramaking4302 Жыл бұрын

@@groslou9997 Thanks bro. This is what was confusing me for so long. I am quite good at sudoku and I was confused how I am not understanding what everyone is calling a simple technique. I can't believe I was overlooking this... I have been using this for so long without realising it...

@elkabat5205 10 ай бұрын

@@groslou9997okay but then I don't need the X-wing right? If I can see that no other 2 can appear in column 7 then its obvious that rows 1 or 3 must have a 2. Am I missing something?

@dras227 2 жыл бұрын

how it is an X pattern? if 2 in A4 is true, then both 2's in C7 and C9 can be true

@MacXpert74 Жыл бұрын

They can't because you need to look at the columns in this case. In both column 4 and column 7 the ONLY 2's are in row A & C, therefore forming a X-wing, this then allows to eliminate any other 2's in those rows. Because if you would place the 2 in C9, you can't place any 2's anywhere in column C7, which would make the Sudoku invalid.

@danielkirby3079 5 ай бұрын

I’m sorry, I listened to the video several times and I never understood where you explained which was the correct 2. One of the comments was between 1:26-1:34 of your video but I didn’t catch it. I did hear where you spoke of eliminating other 2’s in actual rows but couldn’t discern which 2 you picked in the x-wing. Most of the comments seem to be happy with your explanation so I am sure it’s just my ADD or lack of understanding. Could you please explain how you picked the correct 2 in the x-wing and not how you eliminated the other 2’s?

@garondes1 10 ай бұрын

I just don’t get it, there are other numbers that repeat also like the 6 7 and 8, why don’t they form an X wing? why choose the 2 in particular?

@albythegreat4648 8 ай бұрын

Still unsure if that's really a fact you can eliminate the other numbers in the same group or not. Couldn't the 2 still possibly be in the other 2 spots?

@eyefeelpineal4079 6 ай бұрын

Yeah that's what I'm struggling with

@sudharshank8256 Ай бұрын

This method doesn't work. I wonder how this video got so many positive comments

@kennethwoodby4528 2 жыл бұрын

what does it mean when we say that a cell cant see eachother

@LearnSomethingNewEveryDay 2 жыл бұрын

these are also called "peer" cells, they are either in the same block, row, or column, then they "see" each other. Hope that helps.

@oksanaball6494 3 ай бұрын

Why did you pick number 2 and not 6,7 or 8? Number 4 and not 5, 6, 7 or 8?

@aninterviewwith...1702 2 ай бұрын

I'll have to come back to this one. I still don't get it.

@179Kreator 2 ай бұрын

Hello, I applied it in a an expert sudoku and it didn’t work

@Fenar_ 3 ай бұрын

Can someone explain why the twos in column 8 and 9 wouldn't be a possibility?

@RusNad 3 ай бұрын

Because column 7's twos have to be in the top right box, that already eliminates the twos in column 8 and 9

@RusNad 3 ай бұрын

But I think even if they were across different boxes, the x-wing means that if A8 was two, then C4 and C7 would both have to be two, which is impossible.

@groslou9997 Жыл бұрын

What is the method to resolve this sudoku please ? May you resolve fully this sudoku in an other vidéo for exemple plz ?

@kaneshoots 5 ай бұрын

I still can't understand why you choose the 2's in the beginning as there are also, 6s 7s 8s

@alg4943 Жыл бұрын

Does anyone ever find more than one X-Wings in a puzzle?

@sontungo1595 Жыл бұрын

Sorry but I think THIS IS NOT X-wings technique. At example 1, in column 7, there only 2 possibilities for number 2 (A7 & C7) and they also in the same Square 3. Therefore in Square 3, we can eliminate the others number 2 at A8 & C9. There's no need to use 2 number 2 in column 4 as she called this X-wings. (The similiar thing at example 2...). I think she should use other examples for this technique.

@juliafullbusterdododotanmh6837 19 күн бұрын

I agree

@MikeKey91 3 ай бұрын

Everytime I use this I get a mistake. Still no clue.

@elgiztaghiyev3194 9 ай бұрын

There only "E and H" has 2 it means automatically A and C has to have 2 you explain more harder than I think

@ted5669 12 күн бұрын

It’s not a 2x2 rectangle, that would be a square

@florinprisecaru4809 14 сағат бұрын

Why did you eliminate those 2 ? Why should we keep 2 from A7 and not from A8 and C9 column? For me has no logic. Sorry It would be al right if we eliminated all 2 from column 4 and 7. But in this situation 2 can be in A7 and A 8 50 % 50% and the same C and C9.

@betmenizorahovice4843 11 ай бұрын

this looks like cheating to be honest, x wings is too powerful and much more easier to spot that xy wings

@kvothe2144 Жыл бұрын

This video: Let me repeat myself 30 times.

@ramanaross 27 күн бұрын

Sorry, incorrect. This is NOT and X Wing pattern. X Wing logic requires the four setup numbers to be in four different blocks. Your analysis is false because ... if the 2 in Block 2 Row 1 is true, then either of the 2's in Block 3 Row 3 can be true. Likewise, if the 2 in Block 2 Row 3 is true, then either of 2's in Block 3 Row 1 can be true. No eliminations can be made. What you have shown is a setup for a possible Unique Rectangle analysis which requires the four numbers to be in only two blocks.