Learn Some Algorithms - part 4

OK, nearly done. All you have to do now is permute the last layer (PLL). Or in other words, put the top pieces in the right places.

After OLL there are only 21 possible permutations for the last layer. That sounds like quite a lot. But like OLL you don't have to learn them all at once, or indeed at all, because you can get a long way with just a few of them.

The list of PLL algorithms on Bob Burton's site looks a bit daunting. But lets break down what we have into two stages. We have corners to position and edges to position. If we learn one algorithm for moving corners and another for moving edges then we can finish the solve with just those.

1) Corners - I found the T-perm really easy to learn because it flows so nicely. This swaps two corners next to each other and two opposite edges. We don't care about the edge swapping though because we are just trying to fix the corners.

It turns out that if the corners are not already in the right places, then the only possibilities are two corners swapped next to each other, or two corners swapped diagonally. For the first case you do the T-perm once, and for the second case you do the T-perm twice. If you want to go faster then you can learn the Y-perm and swap the diagonal corners in one go.

2) Edges - once the corners are placed then there are only 4 edge cases. The U-perm, the opposite U-perm, the H-perm and the Z-perm. Learn one of the U-perms first because all the other cases can be solved by doing two U-perms. Then if you want to go faster you can learn the others... which I think are all quite easy.

So, you can finish the PLL with just T-perm and U-perm. And you can finish it very fast with only T, Y, Ua, Ub, H and Z ... which is only 6 algorithms.

Later you might want to throw in some other PLLs that are easy to recognise and/or execute. I have also learned the two A-perms and will probably learn the J-perms next.