CFOP method

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CFOP method
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Information about the method
Proposer(s): Donald Taylor
John Conway
David Benson
David Seal
Jessica Fridrich
Hans Dockhorn
Kurt Dockhorn
Anneke Treep
Proposed: 1978 - 1981
Alt Names: Fridrich Method
Variants: FreeFOP, CFCE, VH, ZB, MGLS-F
No. Steps: 4
No. Algs: Total: 78 to 119
F2L: 0 to 41
Full 2LLL: 78 (OLL: 57, PLL: 21)
Avg Moves: ~55
Purpose(s):


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Scrambled cube -> Cross -> F2L -> OLL -> PLL -> Solved cube


CFOP is the most frequently used speedsolving method for the 3x3x3 cube.

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CFOP (Cross, F2L, OLL, PLL, pronounced C-F-O-P or C-fop) is a 3x3 speedsolving method proposed by several cubers around 1981. It is also known as the Fridrich Method after its popularizer, Jessica Fridrich. In part due to Fridrich's publication of the method on her website in 1995, CFOP has been the most dominant 3x3 speedcubing method since around 2000, with it and its variants used by the vast majority of the top speedcubers such as Feliks Zemdegs, Max Park, Sebastian Weyer, Mats Valk, etc.

Origin and Naming Dispute

Jessica Fridrich is often erroneously credited as the sole inventor of CFOP. In reality, many developments were made in the late '70s and early '80s by other cubers who have contributed to the method in its current form. The constituent techniques and their original proposers are as follows:

According to research by James Straughan, the first known publication of the Cross, along with the Layer By Layer method, appears in Donald Taylor's 1978 paper The Group of a Coloured Cube.[1] Additional Layer By Layer variants that started with the cross were published starting in 1979 by David Singmaster, John Gaskin, and others. Its publication by Singmaster in Notes on Rubik's 'Magic Cube' was likely the start of its popularity as a step and as part of the Layer By Layer method. The technique of pairing a first layer corner with a second layer edge then simultaneously inserting first appears in 1979's Solving the Hungarian Cube and also Solving the Hungarian Cube in Less Than 100 Moves by John Conway, David Benson, and David Seal, complete with tables containing algorithms for all possible cases.[2] Other publications of the technique started appearing in 1981 by various sources. OLL then PLL as the last layer method was independently developed by two groups from 1981 to 1983. By Hans Dockhorn, Kurt Dockhorn, and Anneke Treep in the Netherlands and also by Jessica Fridrich and Mirek Goljan in the Czech Republic.

During the resurgence in speedcubing's popularity in the late '90s and early 2000s, there was a general lack of information on the sport. Fridrich's website offered a vast wealth of information for those entering the sport, including a full description of CFOP with complete lists of algorithms. As a result, many who learned from her website began to call this method the "Fridrich Method."

Several high-profile cubers have long disputed this terminology; Ron van Bruchem, famously, has publicly written that he will never call CFOP the "Fridrich Method." This issue has become well-advertised within the cubing community around the year 2008, likely because of this. The term "CFOP" has become more popular since then.

While some cubers still insist on the term "CFOP," Fridrich's contribution to the popularization of the method is undeniable, and many others accept the term "Fridrich Method" as established terminology and a perfectly valid synonym for "CFOP."

Steps

CFOP can be viewed as an advanced version of a Layer-By-Layer method. It takes the same steps, but combines some of them, solving more of the cube at once.


Cross Cross


The first step is to make a cross on the bottom face by solving four edge pieces that share one color (white in this example).

Virtually all top CFOP solvers nowadays solve the cross on bottom to avoid doing a z2 or x2 cube rotation. Previously in the 2000s it was also popular to solve on a different face, for example Cross on left. Many top solvers are also color neutral, meaning they are able to solve the cross on any color. This allows them to find better solutions in many cases.

F2L F2L (First Two Layers)


In between the solved cross edges and their corresponding centers are four slots that contains a corner and an edge piece. The goal of this step is to fill in these slots with the right pieces to solve the first two layers at the same time. This is accomplished by pairing up a corner that shares a color with the cross, and an edge that shares its colors with said corner, then inserting them together. The completion of this step leaves one with just the last layer, typically placed on top.

OLL OLL (Orientation of the Last Layer)


In this step, the goal is to make the top face one color. There are 57 nontrivial cases, and therefore 57 algorithms to learn for this step

Those new to OLL break up the step into two. This greatly reduces the number of cases; 2-look OLL has 9 cases. However, note that this is a few seconds slower

PLL PLL (Permutation of the Last Layer)


Finally, the cube is solved by permuting the pieces of the last layer, in other words putting them in the correct position. There are 21 nontrivial cases for this step.

Those new to PLL break up the step into two. This greatly reduces the number of cases; 2-look PLL has 6 cases. However, note that this is a few seconds slower

Pros

  • Easy to learn - CFOP is widely considered to be the easiest method to learn, as it transitions easily from beginner's methods.
  • Doesn't require a large understanding of how the cube works - Due to the lack of blockbuilding or edge orientation needed in CFOP, the method relies more on pattern recognition and algorithms. Although the cross and F2L are solved intuitively, they are more straightforward than the blockbuilding with Roux or the edge orientation and blockbuilding with ZZ.
  • Is by far the most researched method - As CFOP is the most widely used method and has been for many years, there has been far more research done on CFOP than any other method, which means more resources, a larger variety of algorithms to choose from, and more community members to assist and give advice. All world records for the 3x3 Rubik's Cube since 2003 have been set with CFOP, with the exclusion of Kian Mansour's 9.54 one-handed Ao5 in May 2018.
  • Statistically the fastest speedsolving method - Statistically speaking, CFOP has proven to currently be the fastest method, despite the move count. As of June 1, 2016, the top four speedsolvers in 3x3 average use the method, as well as the top fifteen speedsolvers in 3x3 single.

Cons

  • Move count - CFOP has a slightly higher average movecount than that of ZZ and much higher movecount compared to Roux.
  • Reliance on Inspection - CFOP relies on the use of inspection time, in order for the cross (and the first pair, depending on how advanced the user is) to be solved quickly. In instances where there is no inspection time, such as big cube solves where one must transition between the cube's reduction and 3x3x3 steps, this can be a drawback as the cross has to be done on the fly rather than being planned out. Although this may be the case, CFOP is still the most popular choice for the 3x3x3 stage on big cubes as the planning and execution of a Roux or ZZ solve is typically more difficult than doing CFOP.
  • Difficulty of Cross - Planning the cross during inspection can take a while to master. It requires a fair amount of experience, similar to planning the first block with Roux or the EOLine with ZZ.
  • Rotations - Unlike Roux or ZZ, CFOP has rotations, which may slow one down.

See also


F2L

edit


OLL (edit)


PLL (edit)
Permutations of corners only
Permutations of edges only
Permutations of corners and edges

External links