Rubik’s Cube Notation
In my previous post I asked for help with algorithms without really explaining where they come from or how they work. So, let me explain it now.
When solving a rubik’s cube, you probably need to know some algorithms. We’ve established that. However, before you can use the algorithms, you’ll need to know the notation. Notation is simply a way to label certain actions or positions so that you can refer to them later. An example would be in chess, where Be4xg6 simply means that a Bishop on square e4 captured a piece on square g6.
Don’t worry. Notation for the Rubik’s cube is far simpler than that of chess. So let’s learn it.
We’ll be learning notation for the common 3x3x3 cube, which is probably the one you’re most familiar with. I probably won’t be posting any pictures for this, so use your imagination.
If you have a Rubik’s cube, hold it out in front of you, facing one of the sides. The side you are looking at is the Front. The top is the Up side, and the bottom is the Down side (note that they are not referred to as top and bottom). The Left and Right sides should be obvious. Finally, the side facing AWAY from you is the Back side.
F = Front
U = Up
D = Down
L = Left
R = Right
B = Back
Already the algorithms I mentioned in my previous post should be making more sense now. However, if you notice, I actually have little i’s in there as well. I will explain this.
As it is, the notation above is followed by turning the corresponding side clockwise one time (also known as a quarter turn, or 90°). The small “i” means “inverted” and denotes a counter-clockwise turn. For example, if you see “F” you turn the front side clockwise once. If you see “Fi” that means that you would turn the front side counter-clockwise once.
Even though you are always looking at the “front” side, you always turn a side as though you are facing it. Understand? For example, if your algorithm is “RiDi” then you would pretend you are facing the right side, turn it counter clockwise once, then pretend you are facing the bottom side and turn it counter-clockwise once. Let me put it this way. “Li” would have you turn the left side away from you, because if you turned and looked at it, that would be counter-clockwise. However, “Ri” would be turnning the right side towards you, because if you turned and faced the right side, that’s counter-clockwise. I hope this makes sense to you.
Truly, that’s all there is to know. The notation is simply a set instructions and the algorithms simply the order in which you follow the instructions. So if you have the algorithm “FDUiLiDDR” you now know it means “Front, Down, Up inverted, Left inverted, Down, Down, Right”, and when thinking about it that way, it makes it much easier to follow.
Now, I’ve adjusted my notation slightly from the “standard” in order to create acronyms from them, as mentioned in my previous post. If you look up Rubik’s cube algorithms on the internet, you might notice that many of them will have apostrophes and superscript numeral 2. For example, here is the algorithm I posted in my previous post:
Don’t let the differences confuse you. The apostrophe does the same thing as the lowercase “i”, and the superscript two doesn’t mean “D squared”. It just means to turn it twice (also known as a half turn, or 180°). I actually made it easier by just making it “DD”. Compare both lines above and you will see how they mean the same thing.
As I stated before, one of the reasons I simplified the algorithm was to create an acronym from it so I can remember it. An acronym for F’D²L’ might just be “Fighting Dogs Live”, because you can’t really make a word that starts with ‘ or ². However, if you just remember “Fighting Dogs Live” and later try to perform the algorithm on a Rubik’s cube, you’ll move the cube “Front, Down, Left” instead of “Front inverted, Down, Down, Left inverted”.
Well, that’s enough for now. Once you get used to the notation you’ll be able to follow any of the algorithms with ease, and you won’t even have to look at the cube while doing it.