The last edges
One three-way swap, run once or twice, and the cube finishes in your hands.
By the end you will be able to
- Cycle the last three edges into place and complete the cube
- Tell which way round the cycle needs to go before you start turning
- Deal with the position where no edge is correct
Everything is solved except four edges in the top layer, and often one of those is already right. One algorithm finishes the cube.
Find the edge that is already right
An edge is right when its side colour matches the centre it sits above. Look round all four faces. Usually exactly one edge is already correct; turn the whole cube so that edge is at the back, away from you.
The algorithm
With the correct edge at the back, this sends the front edge to the right, the right edge to the left, and the left edge to the front. Look at where your three loose edges actually need to go. If that is the journey, run it once. If they need to go the other way round, run it twice.
- Turn the whole cube so the already-correct edge is at the back. y
- Check where the front edge belongs. On the right — one go. RU'RURURU'R'U'R2
- On the left — two goes, without changing your grip. RU'RURURU'R'U'R2
When no edge is correct
Sometimes none of the four is right. This happens when the edges need swapping in pairs rather than cycling, and no amount of turning the cube will produce a solved one to hold at the back.
The answer is the same as it was for the corners. Hold the cube any way round, run the algorithm once, and look again — one edge will now be correct. Put it at the back and finish normally.
The moment it finishes
The last move of the last repetition is R2, and the cube comes together underneath your fingers rather than in front of your eyes — you feel the half turn go in and then everything is one colour on every side. It is worth doing slowly the first time.