# Difference between revisions of "First Two Layers"

The First Two Layers

First Two Layers, or F2L are normally the first two bottom layers of the 3x3x3 cube, or essentially all layers up until the last layer on larger cubes.

The definition is a little different depending on the subject or who you are talking to. Normally it is as above but it may also refer to the part of the Fridrich method that solves the pairs without counting the cross part.

## Approaches

### Petrus F2L

Another way to solve the 'F2L' is by building blocks, common during the first two layers of the Petrus method.

### Fridrich F2L

There are many ways to solve the 'F2L' on a cube. A common system is using the Fridrich method first two layer approach. After solving the cross, a corner-edge pair is paired up, and then inserted into the correct slot. A total of four corner edge (or 'CE') pairs are made and inserted to solve the first two layers.

The concept of pairing up four corner/edge pairs was first proposed by Ren Schoof in 1981.

Most people agree that the Fridrich F2L should be done intuitively, but when you are starting out it can be instructive to see some optimal solutions for each F2L pair. Below is a collection of such optimal solutions

## Easy Cases

### F2L 1

 F2L U (R U' R')
 F2L R' F R F'

### F2L 2

 F2L y' U' (R' U R)
 F2L F R' F' R
 F2L d' L' U L

### F2L 3

 F2L y' (R' U' R)

### F2L 4

 F2L (R U R')

## Corner in Place, Edge in U Face

### F2L 25

 F2L R' F' R U R U' R' F

Back Right slot open - (U D' R U' R' D)

### F2L 27

 F2L (R U' R' U)(R U' R')

### F2L 30

 F2L (R U R' U')(R U R')

## Edge in Place, Corner in U face

### F2L 31

 F2L (R U' R') d (R' U R)
 F2L (R U' R' U)(F' U F)

Solved