EG is an advanced 2x2 method. "Full EG" consists of 3 subgroups which have become known as CLL, EG-1, and EG-2. Altogether, this method consists of 120 algorithms. In the EG method there are only 2 steps which, in easier cases, can often lead to a "1-look solve" in which the entire solution is planned out during the 15 second inspection time. The first step is to make the bottom side of the cube one solid color. In CLL all four pieces in that layer will also be placed correctly in respect to each other, thus forming a complete layer. In EG-1 two adjacent pieces will be placed correctly to each other while the other two will need to swap, forming a bar on the bottom layer. In EG-2 the pieces will be diagonally permuted and there will be no bar. The solver can then recognize the case and solve the cube using one of the memorized algorithms.
Not very many people have learnt more than just CLL because knowing only CLL is more than enough to become relatively fast (sub 4 seconds) at solving the 2x2 cube, but EG-1 can further improve times. The current WR average was done using pure CLL.
Not very many people have learnt more than just CLL because knowing only CLL is more than enough to become relatively fast (sub 4 seconds) at solving the 2x2 cube, but EG-1 can further improve times. The current WR average was done using pure CLL.
The above images show the various ways the first layer can be made. The bottom side (white) is solved in all three cases and the pieces are permuted differently. The cases shown would be solved with CLL, EG-1, and EG-2, respectively.