[Help Thread] 4x4 Discussion
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Toddyt1
Regular
Rr is actually the notation I prefer.
What the algorithm does is swap two edges on the top layer, the one facing you away from you. You can apply the algorithm from any side with the top layer on top and then it will be solvable with normal 3x3 methods.
Edit: to clarify by the top layer I meant last layer you're solving in the 3x3 stage.
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I just managed to get this into a state where I could test this, and it swapped 2 edge pieces.. Not corners.
I need to swap the on the same face (not diagonally).. Got an algorithm for that?
Jon
Edit: Hang on. I did it again and it fixed the corners now.. So if I start with the corners wrong and do this, it correct the corners but then breaks 2 edges.. If I do it again, it fixes everything.. Is this correct? Do I just do it twice?
Edit2: No.. I am confused now.. If I start with a completed cube and do this algorithm, I swap 2 opposite edge pieces.. if I do it again, it corrects it.. So I am pretty sure that this just swaps 2 edge pieces.. What if I want to swap 2 corners? The thing I don't understand is that I started with 2 corner pieces wrong (but not correctly rotated) and the first time I did this, it corrected them and swapped the edges, so I am a bit confused as to what I did or what I need to do..
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Username
Legend
Actually, if you swap 2 edges, it's solvable as a 3x3- If you do that alg, you have either a T-perm or a F-perm to do
windhero
Veteran
If 1 edge is flipped over (wrong orientation): Rw U2 x Rw U2 Rw U2 Rw' U2 Lw U2 Rw' U2 Rw U2 Rw' U2 Rw'
If 2 edges are in the wrong places, opposite edges (permutation): RW2 R2 U2 RW2 R2 UW2 RW2 R2 UW2 U2
If 2 edges are in the wrong places, opposite edges (permutation): RW2 R2 U2 RW2 R2 UW2 RW2 R2 UW2 U2
Edges? Perhaps we are at cross purposes, but I am talking corners.
The scenario I had (twice) was that after going through Dan Browns 3x3 solution. The last 2 corners needed to be swapped over.. They were opposite each other (as opposed to being diagonal).
Jon
Noahaha
blindmod
Toddyt1
Regular
If you get to a state where two corners appear to be swapped, doing the edge swap algorithm will put the cube in a state where it will be solvable using normal 3x3 methods.
So if you do that algorithm, with the two corners that need swapping in the top layer, you should then be able to continue the solve using the 3x3 beginners method.
Sorry.. not sure I follow.. Which one would I use if my edges are fine, and 2 corners are not?
Toddyt1
Regular
Uu2 Rr2 U2 r2 U2 Rr2 Uu2
As has been said that algorithm swaps 2 edges, not corners. But after the edges are swapped the cube is in a state where it is solvable as though it were a 3x3.
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Brest
Moderator
4x4x4 Parity Algorithms
Corners swaps, adjacent and diagonal.
Or you can do the "standard" permutation parity, then a T-perm.
r2 U2 r2 Uw2 r2 Uw2 U2 // permutation parity
y' R U R' U' R' F R2 U' R' U' R U R' F' // T-perm
View at alg.garron.us
Corners swaps, adjacent and diagonal.
Or you can do the "standard" permutation parity, then a T-perm.
r2 U2 r2 Uw2 r2 Uw2 U2 // permutation parity
y' R U R' U' R' F R2 U' R' U' R U R' F' // T-perm
View at alg.garron.us
Is that the full algorithm? I just tried it on a completed cube and it made a mess....
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SenileGenXer
Regular
That other alg worked for me. Did what it was supposed to.
r2 U2 r2 Uu2 r2 u2 is what I use for PLL parity. Note the lowercase u at the end. You could do it as Uu2 and then U2 if you need to or just Uu2 if you want to reposition the upper layer. If I run into any PLL case I don't recognize I slice it through the heart with this and it is a PLL case I recognize. Slice the diagonal corners they become an N-perm, slice the adjacent corners they become an T-perm or F-perm. With more experience and experimentation you realize where to slice some of these to get easier PLL cases.
r2 U2 r2 Uu2 r2 u2 is what I use for PLL parity. Note the lowercase u at the end. You could do it as Uu2 and then U2 if you need to or just Uu2 if you want to reposition the upper layer. If I run into any PLL case I don't recognize I slice it through the heart with this and it is a PLL case I recognize. Slice the diagonal corners they become an N-perm, slice the adjacent corners they become an T-perm or F-perm. With more experience and experimentation you realize where to slice some of these to get easier PLL cases.
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Toddyt1
Regular
Yes. uppercase U is out layer turn and lower case u is inner layer turn. Uu would mean turn both layers (another notation would be Uw). This algorithm swaps the edge facing you and the edge in the back.
Yep.. Got the idea that it was BOTH layers...
But I tried it a few times and it keep messing up
So the entire algorithm is Uu2 Rr2 U2 r2 U2 Rr2 Uu2.
Thinking about it, perhaps I had the orientation wrong from the start.
I take it that I would hold it with the 'bad' face facing me (the Front layer)
And then I would turn:
- Top 2 layers 180 degrees
- Right 2 layers 180 degrees
- Upper Layer 180 degrees
- Right Layer 180 degrees
- Upper 180 degrees
- Right 2 180
- Upper 2 180
I will try this again.. Cheers
But I tried it a few times and it keep messing up
So the entire algorithm is Uu2 Rr2 U2 r2 U2 Rr2 Uu2.
Thinking about it, perhaps I had the orientation wrong from the start.
I take it that I would hold it with the 'bad' face facing me (the Front layer)
And then I would turn:
- Top 2 layers 180 degrees
- Right 2 layers 180 degrees
- Upper Layer 180 degrees
- Right Layer 180 degrees
- Upper 180 degrees
- Right 2 180
- Upper 2 180
I will try this again.. Cheers
Toddyt1
Regular
- Top 2 layers 180 degrees
- Right 2 layers 180 degrees
- Upper Layer 180 degrees
- Inner Right Layer 180 degrees
- Upper 180 degrees
- Right 2 180
- Upper 2 180
Edit: The layer with the "bad corners" should be the up layer.
- Right 2 layers 180 degrees
- Upper Layer 180 degrees
- Inner Right Layer 180 degrees
- Upper 180 degrees
- Right 2 180
- Upper 2 180
Edit: The layer with the "bad corners" should be the up layer.
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windhero
Veteran
To clarify; The corners can never be in a wrong place because of parity. Parity concers edge pieces only. It might look like everything else is ok except 2 corners, but in reality its actually the edges that are in the wrong places. After fixing the edges you can solve the cube with a PLL algorithm.
Ahhhh.. I see.. Got it now.. I ran through it again last night and encountered yet another condition (1 edge flipped).. Clearly there will be an algorithm for this, and I have a bit to learn
But I was thinking.. I am not interested in speed.. I just want to be able to do the 4x4, irrespective of how long it takes.. Are there any 'magic' (inefficient but effective) algorithms which can fix many conditions? I know this might sound stupid, but back in the day (30 years ago) I learned the 3x3 and there were unique algorithms for each condition.. Now I have come back to it and done the dan brown method, there are single algorithms which do lots.
Are there any algorithms on the 4x4 which I should learn, which could be used/combined to sort out most/all parity issues?
Jon
Toddyt1
Regular
You only need 2 extra algorithms for 4x4.
Edge swap(PLL parity): Uu2 Rr2 U2 r2 U2 Rr2 Uu2
Edge flip(OLL parity): r2 B2 U2 l U2 r' U2 r U2 F2 r F2 l' B2 r2
There are other algorithms that will do the same, those above are the ones I like to use. Although there are algorithms that solve both parities at once if you are not interested in speed there really is no point learning them as you will have to learn to recognise when both conditions have occurred.
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yockee
Veteran
The Maru is a good cube, but eventually, you're going to have to get a new one because the core will just keep coming misaligned. Get the v2 if you like the Maru feel. Otherwise, just get a ShengShou v5. It's a great cube. 4x4, for me, was the hardest cube to progress with. I was stuck at 1:20 for about 2 years, and just finally jumped down to 1:00 - 1:12. I don't use Yau, I use 32223 reduction. I just find it easier than messing with all those different steps. Maybe I'll switch when I'm down to sub 40, but for now, everyone else got fast with reduction and I will too.
For the OLL parity, most fast people use: Rw U2 x Rw U2 Rw U2 Rw' U2 Lw U2 Rw' U2 Rw U2 Rw' U2 Rw'.
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