Lesson 5
Put the four middle-layer edges in place with the insert-right and insert-left algorithms.
Goal: put the four edges of the middle layer in place. When it is done, the bottom two layers of the cube are solved.
Find an edge without yellow in the top layer: edges without yellow belong in the middle layer. Rotate the whole cube so the centre with the edge’s side colour is in front. Then turn the top layer to bring the edge to the top front with its side colour matching the front centre. The edge’s top colour tells you which way it goes.
The edge without yellow is at the top front and its side colour matches the front centre. The edge’s top colour matches the centre on the right. Do insert right (U R U' R' U' F' U F).
The edge without yellow is at the top front and its side colour matches the front centre. The edge’s top colour matches the centre on the left. Do insert left (U' L' U L U F U' F').
No edge without yellow is left in the top layer, but an edge is wrong in the middle layer. Rotate the whole cube so this edge is at the front right. Do insert right (U R U' R' U' F' U F) once: the edge comes up to the top layer. Then place it like any top edge.
If the edge’s top colour matches the centre on the right, do insert right; if it matches the centre on the left, do insert left. If no edge without yellow is left in the top layer but an edge is wrong in the middle layer, first bring it up with insert right.
Middle layer
U R U' R' U' F' U F
When: For the middle layer. The top front edge has no yellow, its side colour matches the front centre and its top colour matches the right centre.
Finger tip: It has two parts: U R U' R' and U' F' U F. You may pause between them.
Middle layer
U' L' U L U F U' F'
When: For the middle layer. The top front edge has no yellow, its side colour matches the front centre and its top colour matches the left centre.
Finger tip: It has two parts: U' L' U L and U F U' F'. It is the mirror image of inserting to the right.