Unsolvable Rubik's Cube Twisted Corner Use the Rule of Three!

Hi , this is Mali of Rollo Cubing and gaming .

And today I wanted to talk to you about twisted corners .

Twisted corners are the situation on a Rubik's Cube where somebody has forcibly twisted a corner like this .

And sometimes people are working on their cube and they don't realize that a corner has been forcibly flipped .

And so they may get into a situation where their cube is actually unsolvable because of this flipped corner .

And so I see this come up a lot in comments on my tutorial where people cannot solve their cube and they're wondering what's going on .

And so often the situation is actually that they've got a flipped or switched um uh twisted corner .

So I'm gonna show you how you can easily tell if that situation is happening on your cube .

So um the way you do it is you , you count the corners and each corner will have a value based on um like if we were looking at the white side , you would count the corners based on if the white is showing on top , that's worth a zero .

If the white is showing on the right side , that's worth one and if the white is showing on the left side , that would be worth a two .

So right now , this would be , this value of the cube would be zero plus zero plus one plus two or three .

And then if you flip the cube over , you can count these corners .

And because yellow is on the top , these would all be worth zero .

So this cube right now has a value of three .

And when your cube has um a value that's divisible by three , then you know that it's solvable .

So right now we've got a one plus a two is a three .

So this cube is solvable .

So if I go ahead and do step eight of my tutorial , you will see that we will be able to solve this cube .

So I could do this step one more time .

I'm doing the right 1 80 left 1 80 algorithm .

And you can see we were able to solve the cube .

So that was the case when you have corners that add up to three .

But let's see what , see what happens if your corners add up to something that's not divisible by three .

So let's say our corners add up to um let's make it interesting and let's make it add up to five .

So here is , this is a one , this is a one , this is a two .

So that's four .

And then if I twist this one , that would be another one .

So now we've got one plus one plus two plus one .

So we've got a value of five zeros on the bottom .

So now we can go ahead and I'll show you um that you can actually solve the cube just as normal when you've got flipped corners .

And the only you can tell that you've got trouble by counting your corners at any step of along the way , you can count your corners and you could realize there's a situation , but it won't actually show up in your solve until you get to the very final step .

Uh What I call step eight in my process .

And that's where you'll find out that you're just going around and round and you cannot solve your cube .

So let's go ahead and solve this cube just using my , my uh normal method that you can check out on my uh tutorials on how to solve the Rubik's cube .

So I won't go into details what I'm doing there , but I'm just gonna go ahead and solve this , this cube .

So I'm gonna place these white corners and you'll , you'll see that even though I just flipped all those edges , I'll be able to do a normal um solve for this step where I can still put the white corners in place .

And so I'll go ahead and do that and put this corner up here and let's bring that corner out of the way and let's place this final corner .

So you can see , I'm able to go ahead and place my white corners even though I had flipped them all .

Now , I'm gonna go ahead and solve the second layer and that will work as normal .

So when you have these flip corners , you can go ahead and you can get very far in your solve .

Um And you won't really realize that there's trouble until you get to the very final eighth step .

But I'm gonna show you how along the way you can check your corners .

So you can tell if you are in a situation where you've got some flipped corners .

OK ?

Here's our final edge piece .

So here we're about to solve the second layer .

OK ?

We've solved our second layer .

Now , we're gonna work on solving the yellow layer and here we could do a count right now .

And you would see that we still have the situation where there's where there's five , a count of five .

So this one counts as two , this one counts as zero , this counts as two and this counts as one .

So two plus zero plus two plus one , that's a count of five .

So you can see we're still counting five .

So we can go ahead and do our step where we're gonna make the Yellow Cross and that'll work just fine even though we've got the twisted corners .

So we'll go ahead and do that .

We made our Yellow Cross without a problem .

Now , we can do our T that's , we can solve our t without a problem .

So we'll do the right 1 80 algorithm .

So that solves without a problem , check out my video to learn how to do this if you don't already know how .

And so now we're on to step seven .

So this is where we place the corners and we get the right colors in each of the four corners .

And again , you can solve this um without trouble even though we have the flip corners .

So here I'll go ahead and do the lefty algorithm and you'll see that we're able to get our corners into the right place .

So here we've got it .

So we've got this , this has got the right colors for this corner .

This one does two , this one does two blue and red .

This one does two blue and orange .

So we've placed all the corners .

We finished step seven .

So we might think that we're in great shape .

But if we checked our corners , we'd find that we , we still have that situa situation where it adds up to five .

So here's a two , a zero , a one and a two .

So we're still adding up to five .

So let's go ahead and do step a and this is where we're going to realize that our cube won't solve .

So I'm doing the right 1 80 left , 1 80 algorithms .

And you'll see that we're going to keep getting either a five or a two .

We're always gonna have the situation where the remainder is two .

So if you try to divide uh by three , you'd have a remainder two .

So again , here is a one and a one .

So we're now adding up to two .

So remainder two , we can keep trying to do it and we're gonna keep getting the same situation where we have remained or two .

So again , this is a value of one plus one is two .

So you can see that we cannot solve this cube and you can keep doing this over and over and you're gonna keep getting the situation where it adds up to two or sometimes five .

So , so now what you can do though is um we can go ahead and either just flip this corner and , and be done with it or else I'm gonna show you one more time that if we made this uh a value of three .

So this is a two , if we added this a value of one , so two plus one is three , you'll see that this now is a solvable Q because we're divisible by three .

So I do my right 1 80 left , 1 80 .

And you can see we've solved the cube .

So now you know how to check your counters .

Do the count for the rule of three to find out if you have a solvable cube or not .

Thanks .