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Started by keithapparatus at 11-01-2009 3:51 AM. Topic has 4 replies.

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11-01-2009, 3:51 AM

keithapparatus

Joined on 10-25-2009
Orlando
Posts 1

Is this a parity?

I am stuck solving the 4x4x4 Rubik's Cube. I have solved up to the point of picture below. When solving a 3x3x3, typically 2 of the 4 white centers are solved at a time. In this situation the F,R,U,Ri,Ui,Fi alga rhythm doesn't seem to work. All of the youtube tutorials I've found (dan brown in particular) show parities after the rest of the cube is completely solved. Am I encountering this parity issue early? Any suggestions are greatly appreciated. Cheers.

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11-01-2009, 4:40 AM

MoCap

Joined on 10-18-2009
Posts 7

Re: Is this a parity?

I don't know if it's a parity on the 4x4 but it isn't on the 5x5. The only difference with the 5x5 is that the piece in between the badly flipped edge pair would have the same color as the edge pair, but be flipped the opposite way. If you hold the badly flipped edge pair in between the U and F centers, you can do this 5x5 algorithm, which will also fix this case on the 4x4.

r2 B2 U2 l U2 r' U2 r U2 F2 r F2 l' B2 r2

And good luck solving your 4x4.

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11-01-2009, 9:40 AM

borginator2

Joined on 09-30-2008
http://rubiksmaster.com
Posts 825

Re: Is this a parity?

Yes. It is parity. For each of these algs remember:

l is the inner left slice, where as L is the outer left slice. (Ll) means turn inner left and outer left at the same time. The rest of the notation is the same as a 3x3.

Put the edge you want to flip (facing left on your picture) at the top front (so it faces you directly) and do this parity alg. It'll flip a single edge. It is very similar to the 5x5 alg that flips the outer parts of a tredge (triple edge).

r2 B2 U2 l U2 r' U2 r U2 F2 r F2 l' B2 r2

Then you should have your cross.

Then solve as normal. There are 2 other parity cases on the 4x4.

If you get can solve the cube except for a pair of opposite edges that swapped, put one of the edges in front top and the other on back top position and use this:

(Uu)2 (Rr)2 U2 r2 U2 (Rr)2 (Uu)2

If you have a pair of adjacent edges swapped, use this same alg once and you will then be able to solve as normal.

The only other parity case comes earlier when you are pairing up the dedges (double edges). If you have 3 that are unsolved, you can fix them, but if you have only 2 that are unsolved you get parity. Pair them up on front left and front right so they look the same facing you (take a little thinking about until you get the knack), then do this:

(Dd) R F' U R' F (Dd)'

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11-04-2009, 9:49 PM

Ignorancepersonified

Joined on 10-14-2008
Maui
Posts 270

Re: Is this a parity?

I hate when I get that specific parity on the 4x4x4 and 6x6x6. Seems like I get it all the time.

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11-11-2009, 9:04 PM

amazinggolfer

Joined on 11-09-2009
Posts 16

Re: Is this a parity?

Yes, this is a parity case on a 4x4. The move to fix this is: 2R*, 2B, 2U, Ll, 2U, Rr', 2U, Rr, 2U, 2F, Rr, 2F, Ll, 2B, 2R*. If this dosen't work, RobH0629 has a video about parity on Youtube. Thats where I learned all the parity cases. Hope this helps. :)

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