While solving with CFOP, I have the following situation. The bottom side is solved. On the front face, I have the left-center and right-center pieces swapped. How can I swap these pieces? I know that this will affect the top face.

I realize by swapping them, they can face either direction, since an edge piece can be oriented 2 ways. Therefore, I could use 3 separate algorithms. (One for same front face switch position, one for left front to become the right front while the right front gets flipped to the left, and one where the right front becomes the left front while the left front gets flipped when moved to the right).

  • $\begingroup$ How about posting some pictures of your cube? $\endgroup$ – Anonymous Jan 4 at 14:51
  • 2
    $\begingroup$ I'm not sure if I understand your description correctly. But one way, to swap the two edge pieces that are sitting right and left next to the front-facing center would be: F2 U2 F2 U2 F2. $\endgroup$ – npkllr Jan 4 at 15:26
  • $\begingroup$ That's it! Thanks! I should have know this, since I do this on a solved cube. What if one, or both, of those edges were reversed? $\endgroup$ – user6603680 Jan 4 at 22:54

Whenever I have a middle layer edge piece reversed in place OR in the wrong position altogether, I lift it up to top layer with R Ui Ri Ui Fi U F. It has to be on the right side of the front face at the start.

To get it back in the correct position, start by aligning it with the correct side by rotating the top (U). Turn the cube so that that side with the aligned piece is the Front. Then see whether you need to go to the right or left. If you need to go right, first do a U, then same that you just did: R Ui Ri Ui Fi U F.

If you need to go left, first do a Ui, and then do the mirror: Li U L U F Ui Fi


The standard F2L pair algorithms cover all cases, but if you want intuitive rather than fast solution then actually you should not solve layer by layer. As someone commented, F2 U2 F2 U2 F2 works if the edges in question are oriented suitably. However, it is clearly troublesome otherwise. Since it seems that you are not looking for just memory work (otherwise you should just memorize all the F2L pair algorithms), I recommend you instead solve F2L as follows:

  1. Solve the cross on the bottom layer.
  2. Solve only 3 corners on the bottom layer.
  3. Use the unsolved bottom corner to facilitate solving 3 of the middle layer edges. You see, you can rotate the bottom layer to align that unsolved corner with any middle layer edge position and then easily chuck the edge piece in (because you do not care about messing up the unsolved corner).
  4. Solve the last corner-edge pair in any way you want.

If you want to further understand the cube and not rely on any memorized algorithms at all, you should take a look at this post on solving general permutation puzzles, which includes a section on the 3×3×3 cube. In particular, instead of solving F2L completely, one can solve F2L minus one pair and then fix the parity before solving the last 5 edges and then the last 5 corners as described in the linked post.


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