BH Tutorial

[Musturd]

Follow the steps I explained I the tutorial. Where are you messing up?

I'm going to go through B and C in this post:
EXERCISE B. Execute the commutator (URB FRU FUL)
B = R' or F'
I'm going to use R'
A = L' U L (puts corner in)
It puts it to the right spot, so ABA'B'
But that doesn't work...

EXERCISE C. Execute the commutator (URB FLD RFD)
B = D
A = F2 R' F2 (? this works but it seems like it would mess up everything)
B puts the corner to the right spot, so ABA'B'
and that also doesn't work....

(PS: I emailed my Physics teacher and he told me I got a 93! I nailed the A- for the year!!! That should be a ++ for engineering in college)

 

[byu]

@Mustard

Good, you're getting the B section correct.
You're problems are:

in Exercise B:
Your A part has to be careful to not mess up any of the slice that B moves (in this case, the R slice). L' U L doesn't work because it moves away some of the existing R slice pieces. You should only move one. Instead, the proper setup move would be U L U', bringing FRU to FUL. Final commutator should be:

R' U L U' R U L' U'

In exercise C:

Same problem is B, you're messing up too much of the D slice. The proper insertion should be L' U2 L. Final commutator is:

L' U2 L D' L' U2 L D

 

[Musturd]

@byu
I think I understand what I am doing wrong.
Could you give me some more pure commutators to try out (or point me in the direction of where I could find some)?

 

[byu]

Mustard-

Try these 3.

(URB FUL UBL)
(URB FLD UBL)
(URB FDR ULF)

 

[Musturd]

Mustard-

Try these 3.

(URB FUL UBL)

B = L'
but that would ruin the other corner so
B = U
A = R' F' R (but that would ruin the other corner as well...)
so A = F R' F' (?)
B goes where it's supposed to so ABA'B'
and...
it didn't work still
I don't know what I'm doing wrong

 

[byu]

Haha, you were right to start out with. Your B section can ruin other corners, A cannot. Assuming B is L', which it is, A can't mess up any other part of the L slice other than one corner.

I'm not going to tell you the full commutator, I want you to try again.


Oh, and this applies to anyone.

If you want personal live training on BH, contact me through AIM at rubikmaster100. If you don't have AIM, sign up at aim.com

 

[Musturd]

Haha, you were right to start out with. Your B section can ruin other corners, A cannot. Assuming B is L', which it is, A can't mess up any other part of the L slice other than one corner.

I'm not going to tell you the full commutator, I want you to try again.


Oh, and this applies to anyone.

If you want personal live training on BH, contact me through AIM at rubikmaster100. If you don't have AIM, sign up at aim.com

B = L'
A = L' U' L
Messes too much up
A = no idea
I can't find anything that doesn't mess up the other corners...
U would work but it's not 3 moves...
(PS your not answering your AIM)

 

[byu]

@Mustard-

Let me try to break this down even MORE. The A part of the commutator actually takes the form of

CDC'

Where C and D are each 1 move. D is always the opposite slice of B (B is L', so D would be R, R', or R2). C is one of the four sides that is not B or D.

Now, try and do it on your own.

 

[Musturd]

@Mustard-

Let me try to break this down even MORE. The A part of the commutator actually takes the form of

CDC'

Where C and D are each 1 move. D is always the opposite slice of B (B is L', so D would be R, R', or R2). C is one of the four sides that is not B or D.

Now, try and do it on your own.

B = L'
A = F R' F'
didn't work
but I went back to your other commutators
B is opposite
so the whole thing: F R' F' L F R F' L'
Worked!!

At one point I think I understood why B or A went first, but now I don't understand it anymore...

(I'm going to try the next one)

(Sorry it took me a long time to respond, I am currently visiting a bunch of colleges)

 

[Musturd]

(URB FLD UBL)

B = U
A = R D2 R'

R D2 R' U' R D2 R' U
doesnt work
U R D2 R' U' R D2 R'
works

So I can now choose A and B correctly, but I don't understand when to use which order.

This is progress
BTW definately add your latest post to the first post, the CDC' truly enlightened me.

 

[cmhardw]

So I can now choose A and B correctly, but I don't understand when to use which order.

Glad you're starting to like the method, and glad that it is starting to make more sense! It does seem like a lot at first, but trust me. Over time it becomes second nature to see which commutator you need for any given cycle.

As for choosing which direction, whether to use an ABA'B' commutator or a BAB'A' commutator, it all depends on the "lone piece" and which piece the A part of the commutator replaces in the B part slice turn.

Here is a cycle:
(URB RFD ULF)

Here I see that the interchangeability is on the U face. I can interchange URB and ULF with the turn U2. This means that I must insert the RFD corner into the U layer affecting either the ULF or the URB corner, but nothing else in the U layer.

I will do this by A = L D' L'

Now I need to see where the RFD corner needs to go to, and compare this to which spot the A part of my commutator places it. The RFD corner, the lone corner, needs to go to ULF. The A part of the commutator places the RFD corner at ULF. This means that where I need the corner to go from my cycle, and where the A part of my commutator places the RFD corner both line up at the ULF spot. This means I will do an ABA'B' commutator.

Now say I had the cycle (URB ULF RFD)

Here I see that the URB and ULF corners are interchangeable by a U2 turn. I also see that I can insert the lone corner, the RFD corner, into the U layer by A = L D' L'

Now I compare where I want the RFD corner to go with where the A part of my commutator sends it to. I want the RFD corner to go to URB, but the A part of my commutator places it at ULF. These do not line up, therefore I am going to interchange with the B part of my commutator first. I am going to do the turn U2 first, and thus do a BAB'A' commutator.

Whether you do ABA'B' or BAB'A' depends only on where you want to lone piece to go compared to where the A part of the commutator places it.

Hope that helps,
Chris

 

[Musturd]

So I can now choose A and B correctly, but I don't understand when to use which order.

Glad you're starting to like the method, and glad that it is starting to make more sense! It does seem like a lot at first, but trust me. Over time it becomes second nature to see which commutator you need for any given cycle.

As for choosing which direction, whether to use an ABA'B' commutator or a BAB'A' commutator, it all depends on the "lone piece" and which piece the A part of the commutator replaces in the B part slice turn.

Here is a cycle:
(URB RFD ULF)

Here I see that the interchangeability is on the U face. I can interchange URB and ULF with the turn U2. This means that I must insert the RFD corner into the U layer affecting either the ULF or the URB corner, but nothing else in the U layer.

I will do this by A = L D' L'

Now I need to see where the RFD corner needs to go to, and compare this to which spot the A part of my commutator places it. The RFD corner, the lone corner, needs to go to ULF. The A part of the commutator places the RFD corner at ULF. This means that where I need the corner to go from my cycle, and where the A part of my commutator places the RFD corner both line up at the ULF spot. This means I will do an ABA'B' commutator.

Now say I had the cycle (URB ULF RFD)

Here I see that the URB and ULF corners are interchangeable by a U2 turn. I also see that I can insert the lone corner, the RFD corner, into the U layer by A = L D' L'

Now I compare where I want the RFD corner to go with where the A part of my commutator sends it to. I want the RFD corner to go to URB, but the A part of my commutator places it at ULF. These do not line up, therefore I am going to interchange with the B part of my commutator first. I am going to do the turn U2 first, and thus do a BAB'A' commutator.

Whether you do ABA'B' or BAB'A' depends only on where you want to lone piece to go compared to where the A part of the commutator places it.

Hope that helps,
Chris

Thanks, I think I understand now. The A part can brings the piece to the layer it needs to go to. It doesn't just bring the piece to it's correct spot. Right?

 

[cmhardw]

The A part can brings the piece to the layer it needs to go to. It doesn't just bring the piece to it's correct spot. Right?

Exactly

Chris

 

[stiwi griffin]

i have a question,how can you figure out the A move?

p.s.:sorry for the litle bump but i didn't want to make another full thread

 

[stiwi griffin]

there is no one that can help me ?

 

[grolich]

However... FRU and URB are NOT interchangeable, because U' doesn't interchange them (FRU goes to RBU instead of URB).

Interesting. I've only been cubing for a week and a half, but it seems to me that if I get the terminology correct, and FRU is the sticker facing me on the F face on its upper right corner of that face, and URB is the sticker facing the top on the U face in its upper right corner,

an R move brings FRU to URB (and an R' does the opposite), so they do seem interchangeable to me.

Did I understand it wrong or was this a mistake in the original post?

 

[Mike Hughey]

I think he was talking specifically about interchanging with U moves. They're not interchangeable with U, but as you point out, they are interchangeable with R.

Your understanding is correct.

 

[grolich]

I think he was talking specifically about interchanging with U moves. They're not interchangeable with U, but as you point out, they are interchangeable with R.

Your understanding is correct.

Thanks.
This makes a lot of sense.

The entire tutorial is great.

 

[Sakarie]

I only wanted yo say that I have now looked over every possible cycle for corner, and tried to find an optimal solution myself, which worked almost always in the end. If I couldn't, I looked through and compared with the 15 pages I printed out. Right now, I slowly try to make my way through all the A9's and columns, which is those that I have a problem with. This tutorial have helped me a bit, especially with Per Special and Orthagonals. Hardwick's and Beyer's algorithms have helped me very much with everything!

A question: I don't know if I want to start with BH edges now, since m2 still is very fast. But is there somewhere a slight guide to all those names? Sp9, B9, Wide A9 ? I have no idea!

 

[rubiknewbie]

Thanks. I went through the tutorials and sort of understand. Now I want to try it out in actual corner solves. What do you do if the cycle is 2 or greater than 3?

Is there a good place to learn cycle reduction and stuff?