Another F2L thread

On Dennis' page Cubeloop he has a section about the F2L cases where one or both pieces are stuck in the first two layers.

http://www.cubeloop.com/php/cube/expert.php?chapter=f2l&subchapter=stuck

It seems gaspable, but yet I cant find logic in it.

could you (Dennis) or someone else please explain how to think about this?

I can imagine its something like:

(LL is working layer. Side layer pieces are stuck in, also working layer)
but what about cross piece?

I hope you understood that

- Sigurd

so noone knows how to handle these cases?

I'll try to work it out on my own then

What do you mean know how to handle them? It is basically just a F2L trick you can use intuitively.

well I am not so familiar with more than FUR' LU'L' and AUF
ie. setting up either a pair or a potential pair on the U face in a maximum of 5 moves.

could you please descibe what this "trick" is about in short?

I cant emediatly understand whats happening when reading an alg
and I am not used to use F2 moves (breaking the cross completely) wich I can see is heavily used in the "pieces stuck" and "empty slots" (wich might be the essence of this??)

I don't understand what you are getting at. These algorithms help shorten your movecount in F2L, by using empty slots, and giving shortcuts to solving pieces in the wrong slots. What is there to not understand?

He wants to know why the algorithms do, what they do. The 41 standard F2L cases are easy to understand ("hold one piece, move the other, so that they fit" etc.). But these algorithms break the cross, so it's sometimes (at least for me ) not obvious why they work.

What happened on the example on the page is the edge was moved into position so that it could be aligned with the corner correctly when the corner was moved, then it is fixed when this is undone. It is just a sequence of moves that utilize an empty slot to create a pair.

pjk said:

What happened on the example on the page is the edge was moved into position so that it could be aligned with the corner correctly when the corner was moved, then it is fixed when this is undone. It is just a sequence of moves that utilize an empty slot to create a pair.

Click to expand...

I understand that you use the empty slot. and you will either crate a real or potential pair.

but how do I think logically/intuitively about it? (all the cases)
or should I just treat the cases like black box sequences?

let me simplify my original question.

for those of you who uses these shortcuts in the cases where one or more pieces are stuck in incorrect slots. Can you handle these cases as untuivly as regular F2L?

Well, on an 8 sec F2L, you are looking at pieces as they move, and the moves that you are actually solving should be moving so fast that you can't really see them. So when you recognize a pair, you solve it intuitively with your hands, if that makes sense. So those tricks are natural.

I doubt anyone uses all of those. You almost never need to do those cases anyway.

Lt-UnReaL said:

I doubt anyone uses all of those. You almost never need to do those cases anyway.

Click to expand...

I was thinking about this too.. you would rather pick another pair and bring "stuck" pieces up into the top layer when solving the first one.

but I just thought it would be nice to know the theory anyway