Petrus Method
The Petrus Method, invented by Lars Petrus, is a block-building method where the F2L is solved intuitively with no algorithms. Behind Fridrich, it is the second most popular speed cubing method used.
The Steps
1. First, build a 2x2x2 block anywhere on the cube.
2. Next, you expand the 2x2x2 block to a 2x2x3 block.
3. After that, you fix the "bad edges" or orient the remaining seven edges on the cube that have not been solved.
4. Then, you finish the First Two Layers (F2L). The pure Petrus approach is to create a 1x2x2 block and expand it to a 1x2x3 block to finish off the F2L, not to solve the cross piece and two corner/edge pairs.
5. Next, you permute the last layer corners, or put them in their proper places (they do not have to be oriented.)
6. Now, you orient the last layer corners, making the whole last layer a solid color.
7. Finally, you permute the last layer edges, without disturbing anything else, to solve the cube.
Pros
The Petrus Method uses fewer moves than the Fridrich method and most other non-block-building methods. It is more intuitive than the Fridrich method, and it requires far less algorithms.
Cons
It can be sometimes hard (especially for a beginner) to optimize block building, and it's difficult to keep consistently turning throughout the solve.
Where to learn the Petrus Method
Note: Written by the members of the speedsolving forum in this thread: http://www.speedsolving.com/forum/showthread.php?t=3688 - Posted by Rubik's Cube Fan
