Parity fixes

[AvGalen]

I thought it would be nice to have a thread about parity-fixes.

I use "Mackys" 3-cycle method and don't know PLL so fixing parity is important and difficult for me.

This morning I had a really difficult one: UFL and DFR corners and FL and BR edges. It took me about a minute to figure out how to get it into a T-perm but I got it.

Can anyone guess what I did and tell me what they would have done?
And what do you think would be the most difficult parity fix?

 

[Erik]

wow this is a hard one.
Maybe you ehm... yeah what did you do....?...
option 1. orient the corners so that they face the F face do D'R2D then an N perm DR2D' and orient the corners back?
option 2. you quit
option 3. I have no idea

Though I think this is one of the most complicated ones I think that I'll run into even more difficult ones with my TuRBo method since the 2 edge+2corner pieces are not always oriented!

 

[AvGalen]

option 4. Hint: (R2 U2)*3 variation

 

[tim]

option 5: use any 2-cycle method to handle the last few pieces.
In this case use M2 to shoot at FL BR and FL again. Then do M2 and you have to switch DF and UB, which is much easier to handle .

Though I think this is one of the most complicated ones I think that I'll run into even more difficult ones with my TuRBo method since the 2 edge+2corner pieces are not always oriented!

In case of parity with your TuRBo method, i would solve the last pieces the old pochmann way. That's one of the reasons why i haven't completely learned your method yet. I want to find a nice way to handle parity first .

 

[Johannes91]

D' R2 D [N-perm on F] D' R2 D

 

[tim]

D' R2 D [N-perm on F] D' R2 D

That's probably the way i would have solved it, but i think Arnaud looked for a T-Perm only solution.

 

[Mike Hughey]

Arnaud, I remember you had a similar problem with one of the solves in the US Open. And I didn't understand why you worked so hard to think up an ideal solution. I wouldn't think so hard. Instead, I'd just move fast without thinking much. Just do U R2 y (T-Perm) y R2 U', and then solve the 4 edges. (B F H-Perm F' B'.) This is the way Macky suggests, and it's really quite fast, even if it is a few more moves.

Except in cases where corners are all in the top layer, I pretty much always just do the quickest T-Perm I can find. I don't even think about the edges until the corners are done (unless they're really easy, like one setup move away). It's just so much less to think about that way.

 

[Pedro]

I'd solve the corners fist, then the edges...

like...D B2 (T perm) B2 D'
F B (H perm) B' F'

 

[AvGalen]

This is what I did:
DR2U' = setup corners and middle-layer edges
(F2 U2)*3 = Fix middle-layer edges and setup T-Perm
T-Perm = Fix parity
U R2 D' = undo setup

But next time I will just fix the corners with T-Perm and then fix 4 edges with H or Z.

Does anyone have an even harder parity case?

 

[Mike Hughey]

Arnaud, I do have to admit your solution is a lot more fun! But it's just too slow to have to think of it.

For me, the hardest parity cases are when you have corners directly above/below each other, and doing the T-Perm results in a Z-Perm that's hard to set up. But that's the nice thing about doing it this way - there's no such thing as a REALLY hard parity to fix - they're all about the same. I'm just not nearly as good with the Z-Perm as with the H-Perm, especially when it requires setup moves to do it.

If you get a case with just one of the two edges being flipped by the T-Perm, I actually prefer it, since I'd rather do a 3-cycle than just about any 2-2-cycle. But that may just be me.

An example of a typically hard one for me would be UFL DFL FR FD.

 

[AvGalen]

UFL DFL FR FD is easy:
U2 R2 B' makes a T-Perm on the bottom

 

[deadalnix]

A have a tricky tips to solve parity without using PLL. Simply does a U movement, anbd tout get a new cycle of corner witch is 4 pieces long, and another for edges.

So you are in a new position with no edge/corner parity problems.

But you should learn and use T perm, maybe N and J too. IOf you learn T perm, ou will easily learn Y. N and J is a plus to get easier set up moves.

 

[Mike Hughey]

UFL DFL FR FD is easy:
U2 R2 B' makes a T-Perm on the bottom

Of course, you're right. See, this is why solving it your way may make you better than me in the long run. I would never have bothered to discover that. I might have seen it on the top, but not on the bottom. I just never would have even thought about it - I would have been too busy executing my normal process to even notice.

So probably, the next time I get UFL DFL FR FD, I'll probably still find it difficult.

 

[Pedro]

I'd do UFL DFL FR FD as
setup T undo setup
setup H undo setup

like D2 B2 "left-T" B2 D2
F' U2 F' H-perm F U2 F

bad, I know

 

[pjk]

In your case, I would do D R2 U' [T-Perm] U R2 D' to fix corners, then do a U F B [H-Perm] B' F' U'. I don't think that would take too long to do, although thinking about fixing that may be tough during the solve.

 

[Mike Hughey]

I'd do UFL DFL FR FD as
setup T undo setup
setup H undo setup

like D2 B2 "left-T" B2 D2
F' U2 F' H-perm F U2 F

bad, I know

Pretty much what I would do as well. Nice to know I'm not the only one.

I really wouldn't find it all that hard, but my point is that it's as hard as a parity fix gets with my approach. Takes a long time to do, relative to many other parity fixes, and I'm not good at thinking H-perms. (Although I'm finally starting to get better at it.)

 

[AvGalen]

I like finding good parity fixes, hopefully someone has another difficult one

 

[hait2]

how about UFL DBL UR BL?

mine was D' R2 B' S2 Rperm undo

i dunno how you would do it with a Tperm though..
i'll edit out my Tperm solution for now, curious to see others'

 

[Johannes91]

how about UFL DBL UR BL?

F B' [V-perm] B F'

 

[Stefan]

Arnaud, try (R2 B' D2) as setup for a left-handed TPerm on the F face. If you insist on right-handed TPerm on U without cube rotations, try (F B U' F2) as setup.