Andrej Karpathy teaches a standardized method for solving the Rubik's Cube cross stage. Instead of rotating the cube freely, restrict yourself to Y and Y' rotations, then solve each edge using just two canonical cases. The approach trades move efficiency for mechanical consistency, which cuts thinking time and speeds up improvement.
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Hello everyone. This video is a tip for those of you who are averaging about 50 seconds to 5 minutes, so intermediate to beginner, roughly. The reason I decided to make it is that very often I see people make what I believe to be a fairly large mistake while they practice. It looks something like this. Say I was finishing the cross, I would see people do something like this. They would, you know, look around like this, and they would find an edge and they would solve it, and they would find the next edge and then they solve it, something like that. And also for BF2L, they, they do all kinds of things like that. So these rotations that people like to make when they start out, that's a bad thing. The tip essentially comes down to this: standardize your solves. You want all your solves to look as similar as possible, because if you keep running into the exact same situations over and over again, you will keep solving them in the exact same ways and you will improve much quicker. Essentially, your solve will start containing many repeating elements that you can really start to perfect. I'll show you what I mean. I'm going to give you a couple of tips on how you can standardize both your cross and your F2L. So let's start with the cross. We will always hold the cube like this, like this, and the cross layer will be on the bottom. So always like this. You will never rotate around. In fact, the only rotations you are allowed to do is either Y or Y'. Now here's the most important part: we will solve the entire cross always one edge at a time, using only two possible cases. The two cases we'll always look for are when your cross edge is on the top with the white pointing to the top, like here, or when your edge is on the top but the white points towards you. To solve the first case, we will always do the exact same thing: rotate the top layer until your edge aligns on the side with its center, and then turn that face twice to solve it. The second case we will always solve the exact same way as well. First, find where it needs to go. So it's white-blue, so it needs to go here between white and blue, and then place it one position to the right, and then do the following: R' F R to solve it. Those are the only two cases we will ever use, and whenever we don't have any edges on top because they are stuck somewhere on the bottom or in the middle, such as this one, We will first pop those edges out to the top, and then we will solve them using one of the two cases that I just talked about. So in this case, I will first pop it out, restore the cross, and then I can solve it one of the two cases I just talked about. So place it one position to the right of where it needs to go, R' F R, and this one just turn twice. Let's look at a bit more difficult example. So again, we are trying to solve the cross. So here I first notice that I have a white point at the top. I always want to solve those first. It is white-orange, so I will align with an orange on the side and turn the face twice. Here I notice that I have white pointing towards me. To solve these cases, again, it needs to come here, so place it one position to the right, R' F R. Here I have a white that came to the top, so it needs to come Here, align it, turn the face twice. The last edge is not on the top, it's stuck here in the middle. The way you handle these cases is basically you're going to pop it out to the top. To pop it out to the top, I'm going to turn this face, okay, and I'm going to put it away. So let's say, let's put it away there, and then don't forget to always restore your cross just to make sure that you don't screw up what you've already built. And then you can find your edge somewhere on the top, and you just solve it just like we did before. Put it to the right, R' F R. Now clearly, this is not the most efficient way to solve a cross. However, the point here is that we are making cross solving into something that is completely mechanical, something that you can perfect. You should not have to think about it at all while you perform it, and once you are very fast doing it this way, you can then work on perfecting your technique further and getting more elaborate about how you solve every single case. So let's see one more example here. Say I have the cross, we're trying to finish it up. So here, nothing white on the top, so I look on the sides. I see a green, so I find my green, I place it one position to the right, R' F R. There's something on the top now, so I align it, and I do it twice. Again, it's simple pattern matching. I see a blue here, so I'll pop it out, Restart the cross, don't, don't forget, and it points to the top, so I align it on the side and I turn twice to solve it. The last edge, if you notice, is here, so it's somewhere on the bottom, so step number 1, pop it out by rotating it twice. And now it's the top edge, so you know how to solve this. Place it one position to the right, R' F R. Now obviously the technique is very trivial, but that does not necessarily mean that it's much, much slower. So here I'll try to solve a random cross for you using this technique, and let's just see how quickly I can do it. So here we go. Green, orange, red, and blue. So there you go. So it was a bit slower than it probably would have been if I did it as normally, but it wasn't a disaster. So I guess my point is that trying to automate what you do when you solve the cube can be almost just as important as solving it efficiently in terms of the number of moves. Because even though you are taking more time executing these moves, you are spending much less time thinking about them. Now, remember how I said that I'll show you tips for F2L as well? I was only joking about that. No, but seriously, I didn't want this video to be too long, and there's plenty to be said just about how to standardize F2L alone. Not only that, but the target audience for F2L is more advanced, so I will therefore defer that video to later. So that's it for now. Another video that I'm currently planning will be called "How to Solve the Rubik's Cube." for smart people. So I'll try to get it out soon, it should be fun. So stay tuned and bye-bye. Until the edge is on the top, and it will either face up or it will face towards you, so you'll use one of— Oh, sorry, I have a text. Oh, someone's sending me pictures. Oh, this is cool. Okay, wait. So what was I talking about? That solves it. Let's see another one here. This has to come— What the fuck? That was my roommate.
