#### rubiksarlen

##### Member
wait so what is the parity for OP corners (4 blind)? is it t perm + pll parity? I don't really think that's right....

#### Sakarie

##### Member
Could be, if using good setups. But no, the easiest is to solve them normal, after centers, and then (LU'L'U PLL parity U'LUL').

#### canemu

##### Member
In a 4x4 BLD, how would you solve the following centers with commutators: Urb->Ulf->Dlf?

Last edited:

#### cmhardw

In a 4x4 BLD, how would you solve the following centers with commutators: Urb->Ulf->Dlf?

Exactly the same way you would solve the corner cycle: URB -> ULF -> DLF

Try to perform setup moves that will turn the case you have into an 8 move commutator. This particular case has move cancellations that will make it a total of 11 turns to solve. That's for move optimal. For speed optimal you might be able to find stuff that is more finger trick friendly, even if it is more moves.

Hint: Try to do this as a corner 3-cycle before doing it as an x-center cycle. Try to break up the AnI (Adjacent / non-Interchangeable) corner pair of ULF and DLF to make them interchangeable. These two corners will eventually become the two interchangeable corners, and the URB corner will become the "lone corner".

#### riffz

##### Member
In a 4x4 BLD, how would you solve the following centers with commutators: Urb->Ulf->Dlf?

r U2 [r', U' l2 U] U2 r'
= r U2 r' U' l2 U r U' l2 U' r'

#### PCwizCube

I have a question about the Speffz lettering scheme. Is this what it would look like on a 3x3? (Picture below)
http://dl.dropbox.com/u/42308909/Speffz 3x3 Lettering Scheme.JPG

I want to start BLD solving and I think this would be a good lettering scheme to use, but I just wanted to make sure I got it right before I started. Thanks everyone!

#### wontolla

##### Member
That is correct, yes.

#### mDiPalma

##### Member
in competition, what's a safety solve?

#### RyanReese09

When you go slower to make sure you will get the success. Some do safety solves first so they can rush the others. Some do the last solve safety if all the others were DNF.

#### aaronb

##### Member
In 4x4 BLD, when you use commutators for centers; what would be a good method for memorization?

#### emolover

##### Member
*F2 B R U2 D' R' D' U' B F' L' B2 F L B2 F' U' R2 B' R U2 L' D' B L*

Using that scramble and scrambling it using orange on top and blue on front, I use a letter memo system so that UB is A and UL is B that goes counterclockwise on the orange face. Then of the blue face it is the same as the orange but the letters are E F G H. This goes in till the white side than it stops. From that point do an x rotation than that goes the same way the top was. Same with corners but start with the top left corner and go counter clockwise.

Enough with that! I am having trouble with parity. I am not really sure how to do it. I hear you just have to do an R but I doubt it is that easy.

With that scramble I did this solution for corners and edges:

C: C B J F-V T D U-M

E: O T P J-U L W C-Y C B M-Q E P

As you see it would have parity(though I did these solutions separate), now what do I do? When do I solve parity? What do I do? Is there anything special I have to do while memorising?

Thank you anyone for helping.

#### timeless

##### Member
i hate it when i execute a move wrong, then i just wasted my time memoing a cube

#### Zane_C

I am having trouble with parity. I am not really sure how to do it. I hear you just have to do an R but I doubt it is that easy.
I have good news for you, it is "that easy".

I'm going to assume you're using T-perm for the edges and Y-perm for the corners.

For parity (as you know, odd number of corner and edge targets):
-You don't have to memorise any differently.
-If you execute edges first, immediately after you've finished the edges apply the R-perm to swap UB-UL and UBR-UFR.
-If you execute corners first, immediately after you've finished the corners apply the same R-perm.

#### aronpm

##### Member
i hate it when i execute a move wrong, then i just wasted my time memoing a cube

That isn't a question

#### Cubenovice

##### Forever Slow
*F2 B R U2 D' R' D' U' B F' L' B2 F L B2 F' U' R2 B' R U2 L' D' B L*

Enough with that! I am having trouble with parity. I am not really sure how to do it. I hear you just have to do an R but I doubt it is that easy.
...
When do I solve parity? What do I do? Is there anything special I have to do while memorising?

Thank you anyone for helping.

Building on waht Zane-C posted

Assuming Old Pochmann with buffer piece UR
Not R... R-perm

Assuming the standard speedsolving lefty R-perm L U2 L' U2 etc:
you need to make sure it swaps the right pieces so you actually need to do:
y - left R-perm - y' continue solving
or
U - lefty R-perm - U' continue solving

I find that using y y' is more dumb-proof
with U -U' I sometimes get confused with the last U move to the std R-perm...

During memo you just need to make sure that you remember that you have parity and when to execute it.

#### TheMachanga

##### Member
What's the 4x4 edge parity alg again? The one where you have and odd number, and doing r2 just switches the two remaining edges. I know there's a set up involved, but forgot the alg.