This question already has an answer here:
I learnt how to solve a 3x3 Rubik's cube 10 years ago. Every now and then, I picked up a cube, scrambled it, and solved it for fun. I used to work on speed-solving, and memorised lots of formulae for it. However, now I'd like to go a different way: I'd like to solve cubes using the minimal amounts of formulae.
F2L (First Two Layers)
For experienced players, it is clear that with F2L-methods one can solve the first two layers without memorizing any formulae, simply by forming bottom cross, building the 'pillars', and installing the pillars.
I cannot see clearly why the formulae [R'U'F'UFR] (center->bar->L->cross) work, but I have an explanation for it: There are several ways to uninstall and reinstall the pillars that we have installed in the F2L method. By observing what the reinstallations do to the top face, at the end of the day one can write down those that help form the top cross.
The formulae [RU'L'UR'U'L] are similar to the above, but it 'reinstalls' two pillars at the same time.
This is what I really cannot see/understand. I don't even know how people came up with these formulae..
- Does anyone know how people came up with the formulae for the last layer?
- How to better see how the "reinstallations" work for the top face. I know this question is very vague; I am just giving a shot to see if someone has a good way to look at them.