# About big cubes blindfolded...



## Repsela (Mar 9, 2015)

Hi I'm trying to solve blindfolded the big cubes 6x6 and 7x7 with commutators. I have a question. In these cube there's a new kind of centre: the centres obliques. Is it better to solve them with commutators or with U2?


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## Berd (Mar 10, 2015)

Roman has a tutorial on it, in it he explains how there are 2 kinds of obliques (at least on 6x6).


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## tseitsei (Mar 10, 2015)

Repsela said:


> Hi I'm trying to solve blindfolded the big cubes 6x6 and 7x7 with commutators. I have a question. In these cube there's a new kind of centre: the centres obliques. Is it better to solve them with commutators or with U2?



Of course it is better (faster) to solve them with commutators if you know how comms works. But of course it is easier to just use U2 if you don't know comms. Just like any other piece. 

Although obliques are annoying because you have to constantly (well at least I have to) think which layer to turn since you need to use both inner-inner slices and outer-inner slices unlike in any other set of pieces... Also memoing them is somewhat annoying since I sometimes accidentally memo a piece from the wrong oblique set and have to redo that part of the memo later... :/


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## Mike Hughey (Mar 10, 2015)

The commutators for obliques are actually a little easier than the other center pieces. Because they're obliques, they stay out of each other's way better. So there are a number of commutator ideas that work for obliques, but don't work for X or + centers. That's the main reason why obliques are my favorite type of piece to solve. (To be specific, there are cases where X centers don't work, but obliques and + centers work, and there are other cases where + centers don't work, but obliques and X centers work. The nice thing is, if anything works, obliques work!)


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## Repsela (Mar 10, 2015)

Mike Hughey said:


> The commutators for obliques are actually a little easier than the other center pieces. Because they're obliques, they stay out of each other's way better. So there are a number of commutator ideas that work for obliques, but don't work for X or + centers. That's the main reason why obliques are my favorite type of piece to solve. (To be specific, there are cases where X centers don't work, but obliques and + centers work, and there are other cases where + centers don't work, but obliques and X centers work. The nice thing is, if anything works, obliques work!)



Nice to meet you Mike Hughey. Your videos inspired me for big blinds  How many rooms do you use for 6x6 memo? I calculated that I need about 45 rooms with two images per room....and 65 for 7x7...


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## Mike Hughey (Mar 10, 2015)

Repsela said:


> Nice to meet you Mike Hughey. Your videos inspired me for big blinds  How many rooms do you use for 6x6 memo? I calculated that I need about 45 rooms with two images per room....and 65 for 7x7...



Different people do rooms different ways - it sounds like you use a room for what I would typically use a location within a room. I put 9 locations in each room (I have a set journey path between the locations in the room), and typically 3 images at each location. Because of the way I structure it, I need 3 rooms for 6x6x6 BLD. 5 rooms for 7x7x7 BLD, but the fifth room is mostly empty.


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## Roman (Mar 10, 2015)

Mike Hughey said:


> (To be specific, there are cases where X centers don't work, but obliques and + centers work, and there are other cases where + centers don't work, but obliques and X centers work. The nice thing is, if anything works, obliques work!)



Can you bring me one example for each case you told?


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## cmhardw (Mar 10, 2015)

Roman said:


> Can you bring me one example for each case you told?



I can't think of an obliques equivalent to the x-center cycle (Ubl Ufr Dfl) executed as U' f2 U f2 U l2 U' f2 U' f2 U l2

Let l_k mean the kth slice inward from L, and analogous with f_k and b_k. Then, for the obliques case (Ul_2b_1 Uf_1r_2 Df_1l_2) I would do something more like how I would solve (UBl UFr DFl) on wings.

This obliques case also doesn't seem to have a t-center equivalent, and is most closely related to a wings case.


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## Roman (Mar 10, 2015)

cmhardw said:


> U' f2 U f2 U l2 U' f2 U' f2 U l2



Ok then. I never use commutators which have more than 3 moves per part (A or B). I do not find them convinient to execute


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## cmhardw (Mar 10, 2015)

Roman said:


> Ok then. I never use commutators which have more than 3 moves per part (A or B). I do not find them convinient to execute



So you reject the example, then.

Are you implying that no oblique centers case exists that differs from how you execute it on x-centers and/or t-centers?

Also, if you're so quick to reject this example, then please show me an x-center or t-center cycle that you would execute in a similar manner to how you would execute (Ub_1l_2 Uf_1r_2 Df_1l_2) on obliques.


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## Ollie (Mar 10, 2015)

cmhardw said:


> So you reject the example, then.
> 
> Are you implying that no oblique centers case exists that differs from how you execute it on x-centers and/or t-centers?
> 
> Also, if you're so quick to reject this example, then please show me an x-center or t-center cycle that you would execute in a similar manner to how you would execute (Ub_1l_2 Uf_1r_2 Df_1l_2) on obliques.



[M' U2 M, d2] on t-centers and [3r U2 3r', 2d2] on 666 obliques?


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## Roman (Mar 10, 2015)

cmhardw said:


> So you reject the example, then.



No, I do not. My "okay then" means "okay, you're correct then"


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## cmhardw (Mar 11, 2015)

Ollie said:


> [M' U2 M, d2] on t-centers and [3r U2 3r', 2d2] on 666 obliques?



I think [M' U2 M, d2] on t-centers is a corresponding cycle to (Ubl Ufr Dfl) on x-centers.

Both cycles have all pieces interchangeable with each other via a double turn. A quarter turn of either the F or B face in your example will leave only the pieces on the F face as interchangeable. This is also true with the x-center cycle listed.

I don't think the oblique cycle you listed is the same class of cycle, because the piece at the intersection of 3l, 2d, and B is interchangeable with the piece at the intersection of 3l, 2b, and U via a quarter turn, but the other cases have all pieces in a double turn interchangeability setup.

I stand corrected, I thought that the x-center cycle was in a class all it's own, but I think that t-center cycle does correspond to it.



Roman said:


> No, I do not. My "okay then" means "okay, you're correct then"



My bad, I misinterpreted your post :\


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