# 4x4 BLD - A Few Questions



## byu (Mar 22, 2009)

I am trying to learn 4x4 BLD, and I need some help.

1. What do you do for parity? I'm using r2 for edges, Old Pochmann for corners.

2. I can't do commutators for centers blindfolded, i can only do them sighted. Any tips? (This has been a problem for me for a while)


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## KConny (Mar 22, 2009)

1. What kind of parity?
2. Practise?


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## byu (Mar 22, 2009)

1. Permutation parity. Odd number of swaps, r slice is flipped.


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## Lucas Garron (Mar 23, 2009)

1. 2R' U2 2R2 U2 2R U2 2R U2 2L 2R2' U2 2R' U2 2R U2 2L' U2


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## HASH-CUBE (Mar 25, 2009)

hello, in corners, you will shoot them one by one until your done, once you are, count how many corners you just solve, if it is even then no parity for them, but if they were odd, then you will have parity.

parity for corners is where 2 edges (4 in case of 4x4) are swapped, like if you do the J perm, 2 edges will be swapped, so you want to use the parity algorithm to swap 2 edges (r2 U2 r2 U2 u2 r2 u2) where the lower case letter is a move for a single slice, now before this algorithm you have to preform a setup move to get those edge oppisite of each other and oriented, if you do the J perm, the swapped edges will be UR and UB so a setup move will be R' U' R U, then proform the algorithm then unde by doing U' R' U R.

edges have diffrent parity of course, if you shoot edges odd number of times, then you will have r slice centers swapped and the rUF and rDB swapped, so preform this algorithm: r2 D' L' F ( l' U2 l' U2 F2 l' F2 r U2 r' U2 l2) F' L D

so this will be all about parity in 4x4 BLD. 

centers you will have to practice them, use mr. Mike thread to understand them.

any questions you have just ask

thanks


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## trying-to-speedcube... (Mar 30, 2009)

Nah, centers aren't too hard...

Read my tutorial on U2  If it's not explained clearly enough, just post a comment (it's in the tutorial's section)

It also contains a section about commutators, but that's pretty vague


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## byu (Apr 8, 2009)

Lucas Garron said:


> 1. 2R' U2 2R2 U2 2R U2 2R U2 2L 2R2' U2 2R' U2 2R U2 2L' U2



I like that alg, but it doesn't swap centers. Do I just add an r2 at the end? And should I do centers first or last


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## MatsBergsten (Apr 8, 2009)

byu said:


> Lucas Garron said:
> 
> 
> > 1. 2R' U2 2R2 U2 2R U2 2R U2 2L 2R2' U2 2R' U2 2R U2 2L' U2
> ...



Why should it swap centers? It permutes centers of the same colour, so you do centers
first and this alg swaps rFD and rBU (which I call edge parity).

The only thing I do before centers are misoriented corners (so as not to have to remember that so long)


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## Lucas Garron (Apr 8, 2009)

byu said:


> Lucas Garron said:
> 
> 
> > 1. 2R' U2 2R2 U2 2R U2 2R U2 2L 2R2' U2 2R' U2 2R U2 2L' U2
> ...


2R U2 2R2 U2 2R U2 2R U2 2L 2R2' U2 2R' U2 2R U2 2L' U2 

I suggest solving centers before edges, but it's really not important if you're careful (abut parity, etc.)


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