Edge Orientation help

[bamman1108]

I've been looking everywhere and can't find a decent explanation of edge orientation. I'm trying learn ZZ-VH/b and can't even get started because I don't get orientation at all.

I understand how it works in OLLs, but I don't know how to figure out whether a piece is good or bad when the case involves more than one layer.

 

[byu]

Here's what I know about edge orientation:

If a Front or Back face has a Up or Down edge sticker on it, it's not oriented.
If a Up or Down face has a Front or Back edge sticker on it, it's not oriented.
On the Left and Right face, if there is a Front or Back color on the left or right edge stickers or a Up or Down on the top or bottom edge stickers then that's not oriented.

The last bit is hard for me to describe, I used a video to learn it. Hopefully that helps.

 

[Ellis]

I've been looking everywhere and can't find a decent explanation of edge orientation.

Well... didn't it say this on the site you're learning ZZ?

"We define "correct" orientation of an edge to be the one that it can reach from the solved state within the (UDF2B2RL) group*, i.e. without quarter turns on F and B faces. The other orientations are "incorrect". From this definition, we can determine the orientation of an edge by (mentally) moving it to its correct position under this restriction."

So try it. Hold a solved cube in your preferred orientation, and without doing any rotations, scramble the cube however you want without using F/F' or B/B' moves. Any other move is okay, even F2/B2. All edges will be correctly oriented, and you should be able to imagine putting them into a solved position with a sequence of moves that doesn't involve F/F' or B/B'. Then for comparison, Do an F move and note all the edges that are affected. Those edges would be incorrectly oriented and won't be able to be solved without a F/F' or B/B'. That site should also go on to give a more specific way to quickly identify orientations.

I want to add, this is exactly how you orient edges in ZZ, using F/F' and B/B' moves. If you start a solve and there are 4 incorrectly oriented edges, your goal is to use any move besides F/F' or B/B' to get all 4 edges onto either the F or B faces (only one, not both) and then do either F/F' or B/B' depending which face they are on.

 

[bamman1108]

Thanks for that post. I think I get it now.

I'm assuming that The choice of choosing F/B moves is to increase overall TPS by reducing the number of F/B turns?

Lastly, how can orientation be determined quickly enough to plan EOLine during the 15 second inspection?

 

[Ellis]

yes, using one or two F or B moves during the EOLine will eliminate those moves during the first two layers, which will most likely increase the overall TPS.

I actually just decided to try and start practicing ZZ a few days ago, because I realized how powerful it can be, so I haven't really spent too much time on orientation myself. The ZZ website goes further on how to quickly identify orientations, and it does it very specifically. If you really read what it says and think about it, you'll understand the concept.

Actually macky put his site back up, which is where the ZZ site quotes from
http://www.cubefreak.net/BLD/3OP_guide.html#EO

too bad those pictures aren't working.

Basically you're looking at specific edge stickers and you can spot incorrect edges if you see a certain color in a certain place. Just for an example, if you see any U or D colors anywhere on the left or right faces (faces not slices) its incorrect, or if you see any R or L color anywhere on the U or D faces, its incorrect. This really covers everything except for when there is a F or B color on the the RLUD faces, but you can quickly look at the other sticker to rule it as correct or incorrect if you understand the basic rules

 

[blah]

Bear in mind that there's no such thing as a "universally" correctly oriented edge. Different methods differently define what correctly oriented edges are. In English, that means a white-blue piece on UF (with the white sticker on U) may be correctly oriented for method A, but it may also be wrongly oriented if you're using method B.

Here's the definition of a correctly oriented edge for ZZ: If an edge can be solved, i.e. returned to its home position, using only
U U' U2 D D' D2 R R' R2 L L' L2 F2 B2
turns, then it's good, otherwise it's bad.

Going by the definition, you're not going to be able to identify bad edges as quickly as you would want to, so we come up with a few tricks to identify whether an edge is good or bad with just one glance.

Specifically for the ZZ method (and any other method that uses UDF2B2RL restrictions), here's how you determine whether an edge is good or bad with one glance:
1. Most people first look at U, then E, then D (I think ).

For U/D:
2. If a U/D sticker is on U/D, then it's good, don't bother looking at the other sticker.
3. If an R/L sticker is on U/D, then it's bad, don't bother looking at the other sticker.
4. If an F/B sticker is on U/D, look at the other sticker (i.e. the other sticker that's on the same edge piece as this F/B sticker), if the other sticker is a U/D sticker, it's bad, otherwise it's good.

For E: (IMPORTANT: First look out for all the U/D stickers on E, then look at the other edges which do not have U/D stickers, otherwise you're gonna run into ambiguous situations.)
5. If U/D sticker is on F/B, it's good, don't bother checking the other sticker.
6. If U/D sticker is on R/L, it's bad, don't bother checking the other sticker.
7. If R/L sticker is on R/L, it's good (this automatically means F/B sticker is on F/B, i.e. R/L sticker on R/L iff F/B sticker on F/B iff edge is good), otherwise bad.

 

[Stefan]

A shorter method:

Hold the cube with U=yellow and F=orange.
Say white/yellow are brighter than orange/red and those are brighter than green/blue.

Now the one rule is:

An edge is correctly oriented if and only if its brighter sticker is at the brighter center (of the two centers the edge is in between).

Since you'd always hold the cube like that, the centers constellation would always be the same, and the rule can be translated the following, which is more practical:

For edges in the U/D layers, the brighter sticker should be on the U/D face.
For edges in the E layer, the brighter sticker should be on the F/B face.

I have no idea which method is best, though. I'm not using ZZ, my only experience with this stuff is from my early blindcubing days, when I oriented and permuted separately.

 

[bamman1108]

A shorter method:

Hold the cube with U=yellow and F=orange.
Say white/yellow are brighter than orange/red and those are brighter than green/blue.

Now the one rule is:

An edge is correctly oriented if and only if its brighter sticker is at the brighter center (of the two centers the edge is in between).

Since you'd always hold the cube like that, the centers constellation would always be the same, and the rule can be translated the following, which is more practical:

For edges in the U/D layers, the brighter sticker should be on the U/D face.
For edges in the E layer, the brighter sticker should be on the F/B face.

I have no idea which method is best, though. I'm not using ZZ, my only experience with this stuff is from my early blindcubing days, when I oriented and permuted separately.

Would red be brighter than blue and green for this method?

Besides that, thanks for posting this. It's much faster for me than any other methods I've tried.