# EO awareness during F2L (Or: How to avoid rotations)



## Dacuba (Aug 6, 2012)

*EO Awareness during F2L (Or: How to avoid rotations)*

Hello you cubers out there.
My name is Erik not Akkersdijk, living in Germany and 18 years old. I've never written an article about anything, so please don't yell at me. This is meant to be read by cubers who are still having trouble with bad F2L solving. Experienced cubers will hardly find anything new, but you may want to take a quick look if you missed something on your way.
I don't know how useful this will be. If I get positive reactions I will consider writing about other topics, too. If not, then at least I have collected some thoughts for myself.

I want to introduce you to Edge Orientation (EO) during F2L. Ever asked for advice on your video performance? A common reaction is "You make too many rotations". So there you are. But how exactly do you avoid them? In this little essay I want to explain some things you can do about rotations.

The first paragraph is about avoiding rotations without using edge control. It is simply about finding out which cases can be solved without F/B or y/y' in general. It also explains what good and bad edges are and how you recognize them, you will need that for the other paragraphs. Don't be afraid of learning about edge control and good/bad edges, it is not difficult. I promise.

*1. Avoiding rotations by using R,U,L,D moves only*

A good question is: What causes rotations? Roations are made to avoid awkward F and B moves. That means, every time a cuber feels the need of using F or B moves, he makes one or more roations to avoid them. A good first step is being aware of which cases can be solved rotationless with neither F nor B moves. So you can figure out the RULD solution for these cases and never make a rotation for those again.
So: Which cases can be solved with RULD only?

Here is a definition: A F2L case can be solved with RULD moves, if the edge of the pair is oriented correctly. If an edge is oriented correctly let's call it "Good edge", otherwise we call it "Bad edge". So we better use the following rule of thumb:
* A F2L cases can be solved with RULD moves, if the edge of the pair is good.*
It is a piece of cake to recognize if an edge is good or bad. Put the edge anywhere except the M-slice. If the R/L Sticker matches with the centerpiece or the opposite centerpiece the edge is good. If not, it's bad. You will be able to tell immediately if any edge is good once you are used to it.
*Note: When you do y or y' the orientation of all edges in the U-Layer change, but the orientation of the edges in the E-Layer keep the same.* A y2 changes nothing.

What you should do _now_ is to figure out on which RULD cases you are still doing y-moves. These rotations are 100% unnecessary. Figure out the RULD solution for these cases to avoid a huge amount of y-moves during your solves. You can look up good algs on speedsolving wiki if you want to.

This is the easiest thing you can do to avoid roations. Everytime you notice you did a y-move on a good-edge-pair, find out the RULD solution for the next time.

*2. Choose wisely when you use y and y' - Choose which pair you better solve next*

This is a simple idea explained quickly. Imagine you have two good and two bad edges after the cross. What you want to do is to make first both good edges, then use y/y' only once to turn the other edges into good ones and solve them. Otherwise you are going to use y more than one time, which costs you time. Keep in mind that y/y' does not change an EO of the edge is in the E-slice. For example you can wait with good E-slice edges till the end. And if a bad edge is in the E-slice, you should put the edge out before you use y/y' otherwise you are going to do two rotations. Play around with it and you will get better with time.

You should tend to use y in a way that the solved slots are on the Back side for better look ahead. 

*3. Avoiding rotations by using sledgehammers*

You need this little information: A LL edge is good if you can put the yellow sticker on the U-Face with RULD only. (without using y/y' of course)

The best thing that can happen is that all F2L edges are good after the cross is solved, because then you don't need any y-moves for F2L (see paragraph 1). Thus it is an advantage if you can turn bad edges into good edges. This happens if you use the sledgehammer (R' F R F' and mirror) sometimes instead of the standard insertion. This is because F (and B) moves also change Edge orientations. Set your cube up with a sexy move. If you insert the pair now with a sledgehammer the FR-Edge and the UF-Edge will change the orientation, all others won't. So if you build a pair during F2L and just have to put it in, think about if you want to use the sledhammer.

You always use it if both FR and UF Edges are bad, also considering LL edges.
If both edges are F2L edges, but only one is bad, it doesn't really make sense to use the sledehammer. You can do it if it is faster in your situation or if you take the next pair into consideration.
If both are good F2L edges you obviously don't use the sledgehammer.
If there is a F2L edge and a LL edge, I recommend to use the sledgehammer if the F2L edge is bad and to not care about the LL edge. Of course it also depends (maybe you can have all LL edges oriented or avoid a dot case), so sometimes it makes sense to use the standard insertion here.

If someone knows a fast way to do the sledgehammer on the Back please let me know 

*4. Use sexy Algortihms that involve F or B moves*

There are a few algorithms that are fast despite they have F moves. For example:
Setup: Inverse of Solution
Solution: F' L' U L F R U R'

and mirror.

You can use those algorithms or a y-move + RULD solution depending on the next cases. You can control edges with them. _Observe, find out when you want to do which algorithm_, similar to the sledgehammer.

*5. There is more than one cross solution*

Simple idea: Next time you see two obvious cross solutions and think "Well that doesn't matter", think about how it changes F2L edges. Choose the solution with the most good edges as a result. Also use u-Moves to solve a pseudocross since it involes a y.

*6. Combine stuff, practise*

Now you know several things about EO and edge control and how it affects your F2L. Think about what is the best to do in specific situations, your skill at this will become better with time. You have to practise and always be aware of what you are doing. What does make sense, what does not?
Don't be on a rail track, fly instead.

Cheers,
Erik not Akkersdijk


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## Escher (Aug 6, 2012)

To all people interested in this kind of thing, I wrote this thread a couple years back with a few examples and a similar set of ideas (though I neglected the use of sledgehammers):

http://www.speedsolving.com/forum/showthread.php?25525-F2L-Edge-Orientation-guide

Good to see people writing threads like this Erik, I haven't done one in a long while and I was hoping other people would start doing conceptual threads too.


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## bran (Aug 6, 2012)

Nice!


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## Cubic (Aug 6, 2012)

THANK YOU!:tu


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## already1329 (Aug 6, 2012)

Good article.


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## Petro Leum (Aug 6, 2012)

better explained than i ever could, but isnt that common sense?


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## Dacuba (Aug 6, 2012)

Thank you for the positive reactions. Especially I feel honoured by Escher's appreciation 
If I can think of other good topics it is possible that I'll write another article in the future.



Petro Leum said:


> better explained than i ever could, but isnt that common sense?



I don't think it's important if it is common sense as long as it helps people


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## Hendo (Aug 16, 2012)

Your article is really helpful. You mentioned a few tricks I didn't know and will definitely use in the future. Although I'd add a section about r, l, d, u moves that also change EO and actually there is couple of fast and very fingertrick-friendly algorithms that could solve misoriented pair without cube rotations 
Good job and keep it up!
Cheers


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## Daniel Wu (Aug 16, 2012)

Dacuba said:


> There are a few algorithms that are fast despite they have F moves. For example:
> Setup: R U' R' F' L' U' L F
> Solution: F' L' U L F R U R'


Woah I didn't know about this. I would have immediately defaulted to U' y L' U2 L U2 L' U' L U' L' U' L because I hate that case. That's pretty cool.


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## kbrune (Aug 16, 2012)

A little info about me so you know where I'm coming from: Ave is aprox 26 seconds, I struggle with consistent F2L solving and look ahead, I also struggle with cube rotations. 

I'm not trying to be mean or disrespectful but I didn't understand much of it and it's application. It could be because I am more of a visual learner. I did like the example you gave. Maybe you could add an example for each Section you are talking about to appeal to different type of learning styles? What I got from it all is that you should look at all the edges after cross solving and correct edge orientation instead of using rotations to facilitate solving a pair? so basically, cross, fix EO, then solve pair? I'm sure I'm not following because that seems to take longer. 

If everyone else understands perfectly then I guess i'm the weirdo! Apologies if this stuff is obvious to most ppl!


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## sneaklyfox (Aug 16, 2012)

rickcube said:


> Woah I didn't know about this. I would have immediately defaulted to U' y L' U2 L U2 L' U' L U' L' U' L because I hate that case. That's pretty cool.



Not sure if I can fingertrick the F' L' U L F R U R' well. I would have done y U L2 U2 L U L' U L2.


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## Petro Leum (Aug 17, 2012)

you might want to try this alg:
R' u' R u R

inserts a badly oriented pair in FR slot. hurts the edge of FL slot though, so be cautious when using. also try mirrors and inverses


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## Cubic (Aug 17, 2012)

I am using a lot of d moves to avoid rotations, and I'm employing D moved to match pairs from below rather then above. Once matched from below, I can simply swing out the matched pair, D', then insert in the correct position. Much quicker.

Now need to work on look ahead and inserting from different angles.


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## MarcelP (Aug 17, 2012)

rickcube said:


> Woah I didn't know about this. I would have immediately defaulted to U' y L' U2 L U2 L' U' L U' L' U' L because I hate that case. That's pretty cool.



Yeah, me too. It would be cool to have a whole page of these


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