# Help with parity



## Sakarie (May 24, 2009)

I'm using Old Pochmann corners and m2 för edges, and normally I solve parity with 

(U'D R' U' R U R U R U' R' D') m2

which means that my first edge to memorize is UB, since I've alread done a m2-move, and UF and DB changed place. So far, so good.

My problem is that I was thinking about starting to memorize edges&corners, and solve corners&edges. That means that while memorizing edges, I don't know if it's parity or not, which means that I don't know wether I should start memorizing with m-slice changed or not. 

Anyone else had this problem, and knows an answer?


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## Ellis (May 24, 2009)

You don't need to know if there's parity when you start memorizing edges. Parity is something you fix while solving, and your memo shouldn't change at all whether or not there is parity. 

To fix parity, I do what fanwuq suggested. If there is an odd number of corners and edges in my memo, I solve all the corners first except the last one then solve the edges normally, Then do parity fix (U' F2 U M2 U' F2 U, does the same thing as your alg), then solve the last corner. Even if you did solve all the corners first and you had parity, you still don't need to edit your memo. You could do All corners, Y-perm, all edges, parity fix, Y-perm.


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## Sakarie (May 24, 2009)

Ellis said:


> You don't need to know if there's parity when you start memorizing edges. Parity is something you fix while solving, and your memo shouldn't change at all whether or not there is parity.
> 
> To fix parity, I do what fanwuq suggested. If there is an odd number of corners and edges in my memo, I solve all the corners first except the last one then solve the edges normally, Then do parity fix (U' F2 U M2 U' F2 U, does the same thing as your alg), then solve the last corner. Even if you did solve all the corners first and you had parity, you still don't need to edit your memo. You could do All corners, Y-perm, all edges, parity fix, Y-perm.



Oh, that's great! It's a little bit "messier" than my previus method, but I'll try if I like memorizing corners or edges first. If i prefer the latter, I'll use this method for sure! Thanks!

That's a good and easy alg too, but since I'm used to my older, I'll use that instead.


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## Ellis (May 24, 2009)

Sakarie said:


> Ellis said:
> 
> 
> > You don't need to know if there's parity when you start memorizing edges. Parity is something you fix while solving, and your memo shouldn't change at all whether or not there is parity.
> ...



What? I'm saying that it doesn't matter if you memorize corners or edges first since parity has no effect on memo. I memo edges then corners and solve corners then edges. Doesn't matter either way though, whatever is easiest. And how is it messier? Your way cycles 3 edges before you even solve edges... that is incredibly messy and unnecessary, nobody does it like that.


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## Sakarie (May 24, 2009)

Me: Memo Corners & edges, solve corners, parityalg, solve edges.
You: Memo Edges & Corners, Solve corners but 1, solve edges, parityalg, solve 1 corner.

How can you say your (sing. and plur.) is easier?

(This isn't an accusation, just a question to make me understand)


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## Ellis (May 24, 2009)

Because your parity fix will cycle 3 edges, so it completely messes up the edges from what your memo is. Have you actually tried it that way? Is it actually easy?

Besides, leaving one corner is only in order to save moves. I gave an alternative if you didn't want to do it that way, it will just take 2 extra perms. Definitely not as messy as changing the position of your edges from what you memo'd them as.

Edit- Sorry, I don't mean 3 edges are cycled because you fix that with the parity fix. What I meant is that your edges aren't as you memo'd because the M slice is flipped.


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## Sakarie (May 25, 2009)

Of course I don't use a method that forces me to solve pieces in another place than I memo'd! (It might be smart in more advanced tecnics, but I'm certainly not there yet)

Starting with a m2-move, the UF and DB is changed (DF and UB is corrected in the parityfix), which means that in move 1, 3, 5 and so on, the M-slice would be wrong; when it usually is 2, 4, and 6 (so on). That means that if I memo that first m2 in the parityfix as my first letter, I will have a flipped M-slice on 2, 4 and 6 instead, just like you always have on m2.


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