What would you do in this situation?

[masterofthebass]

I just ran into an interesting case while solving. During my f2l, when I inserted my 2nd pair, it ended up going in with the edge flipped. That's normal, but it happened to be that the 4th pair was also flipped. I really had no idea how to go about doing this, so I gave up on the solve. I'm wondering if anyone else has a better way of doing it, other than the standard algorithms.

 

[Bryan]

when I inserted my 2nd pair, it ended up going in with the edge flipped. That's normal

Huh? What method do you use where edges flipped in F2L are "normal"?

 

[jonny guitar]

You mean like an algo that will flip both edges in the process? I my opinion, for how often the case comes up, it would hardly be worth the brain space to memorize one.

If they are adjacent edges in opposite places with the face colour complete it is an easy fix. I sometimes purposely put in the second one in the wrong place if one already exists then put them on the right side and do R2 B2 R2 B2 R2 B2 (I think that is it..don't have a cube in front of me right now).

 

[masterofthebass]

Ok, the case is what you would get for a 2 flip in BLD, M' U M' U M' U2 M U M U M U2, but in the f2l.

 

[Pedro]

exactly, just do a setup, that alg, undo setup

 

[Karthik]

exactly, just do a setup, that alg, undo setup

Thats exactly what I would have done.

 

[watermelon]

If the two pairs with flipped edges are adjacent (FR and FL slots), why not use F (r U r' U')*3 F'?

 

[Lucas Garron]

If the two pairs with flipped edges are adjacent (FR and FL slots), why not use F (r U r' U')*3 F'?

Ooh! Better! I used to do x' U (RUR'F')(RUR'F')(RUR'F') U' x.

EDIT:
Optimal in URF:
Adjacent:

R F R U' F' R2 F R U R F R' F' R' F' (15f*)
R' F' R' F' R F U F R F2 R' U' F R F (15f*)
F R F R F' R' U' R' F' R2 F U R' F' R' (15f*)
F' R' F' U R F2 R' F' U' F' R' F R F R (15f*)

Opposite:

U R U F U' R' U' R F' R2 F2 R F' R' F' R (16f*)
U' R' F R F R' F2 R2 F R' U R U F' U' R' (16f*)
R U F U' R' U' R F' R2 F2 R F' R' F' R U (16f*)
R U F2 U' R' F' U' R2 U R' F2 R2 F2 R2 F' R' (16f*)
R U2 F2 U2 F R' F2 R U F R U2 R' U F2 R' (16f*)
R F R2 F2 R2 F2 R U' R2 U F R U F2 U' R' (16f*)
R F2 U' R U2 R' F' U' R' F2 R F' U2 F2 U2 R' (16f*)
R F' R' F' R F U F R F2 R' U' F R F R2 (16f*)
R2 F R F R F' R' U' R' F' R2 F U R' F' R (16f*)
R2 F' R' F' U R F2 R' F' U' F' R' F R F R' (16f*)
R' F R U' F' R2 F R U R F R' F' R' F' R2 (16f*)
R' F R F R' F2 R2 F R' U R U F' U' R' U' (16f*)

I need to try these sometime...

 

[Swordsman Kirby]

I just don't get myself into these situtations.

 

[ExoCorsair]

I just don't get myself into these situtations.

That's the correct answer.

 

[masterofthebass]

I just don't get myself into these situtations.

The only problem with this, is that it happened completely by accident. there was no real way for me to stop it, because I didn't realize that the 4th pair was already inserted. O well, it never happened to me before, and probably won't for a while.

 

[Lt-UnReaL]

Optimal in URF:
Adjacent:

R F R U' F' R2 F R U R F R' F' R' F' (15f*)
R' F' R' F' R F U F R F2 R' U' F R F (15f*)
F R F R F' R' U' R' F' R2 F U R' F' R' (15f*)
F' R' F' U R F2 R' F' U' F' R' F R F R (15f*)

Opposite:

U R U F U' R' U' R F' R2 F2 R F' R' F' R (16f*)
U' R' F R F R' F2 R2 F R' U R U F' U' R' (16f*)
R U F U' R' U' R F' R2 F2 R F' R' F' R U (16f*)
R U F2 U' R' F' U' R2 U R' F2 R2 F2 R2 F' R' (16f*)
R U2 F2 U2 F R' F2 R U F R U2 R' U F2 R' (16f*)
R F R2 F2 R2 F2 R U' R2 U F R U F2 U' R' (16f*)
R F2 U' R U2 R' F' U' R' F2 R F' U2 F2 U2 R' (16f*)
R F' R' F' R F U F R F2 R' U' F R F R2 (16f*)
R2 F R F R F' R' U' R' F' R2 F U R' F' R (16f*)
R2 F' R' F' U R F2 R' F' U' F' R' F R F R' (16f*)
R' F R U' F' R2 F R U R F R' F' R' F' R2 (16f*)
R' F R F R' F2 R2 F R' U R U F' U' R' U' (16f*)

I need to try these sometime...

Other way around?

Also wouldn't there be faster ones because these also keep the permutation of the top layer?

 

[watermelon]

These ignore the LL entirely and are optimized for URF.
Adjacent:

F U2 F2 U F R2 U2 F2 R F2 U2 R2 (20q, 12f*, 12s)
F R' U' F R F R2 F R U R F (13q, 12f*, 12s)
F' U R2 F2 R U' F R' F R2 U F (15q, 12f*, 12s)
F' U' F' U R U F U2 F' R2 F' R (14q, 12f*, 12s)
F' U' R2 F' R F' U R' F2 R2 U' F (15q, 12f*, 12s)
F' U' R' U' R' F' R F U F2 R F (13q, 12f*, 12s)
F' R' U' R' F' R2 F' R' F' U R F' (13q, 12f*, 12s)
F' R' F2 U' F' R' F R U R U F (13q, 12f*, 12s)
R2 U2 F2 R' F2 U2 R2 F' U' F2 U2 F' (20q, 12f*, 12s)
R' F R2 F U2 F' U' R' U' F U F (14q, 12f*, 12s)

Opposite:

F U' F' R2 U' F2 U F R U' F2 R (15q, 12f*, 12s)
F U' R' F' R' U2 R U F U R2 F' (14q, 12f*, 12s)
F R2 U' F R U R2 U' F2 R' U' R (15q, 12f*, 12s)
F R2 U' F' U' R' U2 R F R U F' (14q, 12f*, 12s)
R' U F R F U2 F' U' R' U' F2 R (14q, 12f*, 12s)
R' U R F2 U R2 U' R' F' U R2 F' (15q, 12f*, 12s)
R' F2 U R U F U2 F' R' F' U' R (14q, 12f*, 12s)
R' F2 U R' F' U' F2 U R2 F U F' (15q, 12f*, 12s)

Unfortunately I didn't notice any particularly fingertrick-friendly algs at first glance...

 

[Harris Chan]

I guess the lesson here is: don't wait till the last 2 pairs to fix this F2L problem

 

[Lucas Garron]

Anyone thinking of comms like these?
[RF'UFR', E/E'/E2]
[R'FRF' RU'R', E/E'/E2]

There are a lot of comms based on this idea (most of which also preserve LL, which is actually great if these are your last two slots).