Speedcubing

Erik Akkersdijk solving a 3×3×3 Rubik's Cube in 10.50 seconds.

A speedsolver completing a 3×3×3 Rubik's Cube.

Speedcubing (also known as speedsolving) is the activity of solving a variety of twisty puzzles, the most famous being the Rubik's Cube, as quickly as possible. For most puzzles, solving entails performing a series of moves that alters a scrambled puzzle into a state in which every face of the puzzle is a single, solid color. Some puzzles have different requirements to be considered solved, such as the Clock, for which all the dials must be moved into the 12 'o clock position.

Most cubes are sold commercially in variations of 2×2×2, 3×3×3, 4×4×4, 5×5×5, 6×6×6, and 7×7×7, although variations of the puzzle have been designed with as many as 17 layers. The current world record for a single solve of the 3×3×3 in competition is 5.25 seconds, set by Collin Burns in April 2015.

Speedcubing is a popular activity among the international Rubik's Cube community, or cubers. Members come together to hold competitions, work to develop new solving methods, and seek to perfect their technique. As a part of the community, puzzle builders and modders try to invent new forms of combination puzzles.

History

The Rubik's Cube was invented in 1974 by Hungarian professor of architecture, Ernő Rubik. A widespread international interest in the cube began in 1980, which soon developed into a global craze. On June 5, 1982, the first world championship was held in Budapest, Hungary. 19 people competed in the event and the American Minh Thai won with a single solve time of 22.95 seconds. Other notable attendees include Jessica Fridrich and Lars Petrus, two people who would later be influential in the development of solving methods and the speedcubing community. The height of the Rubik's Cube craze began to fade away after 1983, but with the advent of the Internet, sites relating to speedcubing began to surface. Simultaneously spreading effective speedsolving methods and teaching people new to the cube to solve it for the first time, these sites brought in a new generation of cubers, created a growing international online community, and raised the profile of the art. People prominent in this online community, such as Ron Van Bruchem, Tyson Mao, Chris Hardwick, and Ton Dennenbroek, eventually wanted to meet in person and compete, so twenty years after the first world championship they orchestrated a second one in Toronto in 2003, and another smaller competition in the Netherlands later that same year. This revival of competition sparked a new wave of organized speedcubing events, which include regular national and international competitions. There were twelve competitions in 2004, 58 more from 2005 to 2006, over 100 in 2008, and over 450 in 2014, with more happening every year. There have been seven more World Championships since Budapest's 1982 competition, which are traditionally held every other year, with the most recent in São Paulo, Brazil, in 2015. This new wave of speedcubing competitions have been and still are organised by the World Cube Association (WCA), founded by Ron van Bruchem.

Solving methods

The standard Rubik's Cube can be solved using a number of methods, not all of which are intended for speedcubing. Although some methods employ a layer-by-layer system and algorithms, other significant (though less widely used) methods include corners-first methods, and the Roux method. CFOP, Roux, ZZ and Petrus are often referred to as the "big four" methods, as they are the most popular and fastest.

CFOP method

Main article: Fridrich Method

The CFOP (Cross - F2L - OLL - PLL) method, also known as the Fridrich Method, was named after one of its inventors, Jessica Fridrich, who finished second in the 2003 Rubik's Cube World Championships. While it is known as the Fridrich method, its origins are actually credited to David Singmaster, who was one of the first to publish a layer by layer method of solving in 1980, and Guus Razoux Schultz, who built upon this and developed a more efficient system for the first two layers (F2L). Jessica Fridrich then finished developing the method and published it online in 1997, an event that was very influential in the revival of competitive speedcubing. The first step of the method is to solve a cross-shaped arrangement of pieces on the first layer. The remainder of the first layer and all of the second layer are then solved together in what are referred to as "corner-edge pairs" or slots. Finally, the last layer is solved in two steps — first, all of the pieces in the layer are oriented to form a solid color (but without the individual pieces always being in their correct places on the cube). This step is referred to as orientation and is usually performed with a single set of algorithms known as OLL (Orientation of Last Layer). Then, all of those pieces are permuted to their correct spots. This is also usually performed as a single set of algorithms known as PLL (Permutation of Last Layer).

The CFOP method is a widely used speedcubing method. Its popularity stems from the speed at which it can be easily performed. Many advanced speedcubers have also learned additional sets of algorithms for the last layer, such as Zborowski-Bruchem Last Layer (ZBLL), which solves the last layer in one step if the edge pieces are properly oriented, and CLL, which simultaneously permutes the corners of the last layer during the OLL step.

Roux method

The Roux method was invented by French speedcuber Gilles Roux. The first step of the Roux method is to form a 3×2×1 block placed in the lower portion of the left layer. The second step is to create another 3×2×1 on the opposite side. The remaining four corners are then solved using a set of algorithms known as CMLL (Corners of the Last Layer, without regard to the M-slice), which leaves six edges and four centers that are solved in the last step.

This method is not as dependent on algorithm memorization as the CFOP method, since all but the third step is done with intuition as opposed to predefined sets of algorithms. The Roux method can more easily be performed without rotations (unlike the CFOP method) which means it is easier to look ahead (solving a collection of pieces while at the same time looking for the solution to the next step) while solving.

ZZ method

The ZZ method, short for Zbigniew Zborowski, is a modern speedcubing method originally proposed by Zbigniew Zborowski in 2006. The method was designed specifically to achieve high turning speed by focusing on move ergonomics, and is the combination of a block-building method and a layer-by-layer method. The initial pre-planned step is called EOLine, and is the most distinctive hallmark of the ZZ method. It involves orienting all edges while placing two opposite down-face edges aligned with their corresponding centers. The next step solves the remaining first two layers using only left, right, top and bottom face turns, one of the advantages of ZZ. On completion of the first two layers, the last layer's edges are all correctly oriented because of edge pre-orientation during EOLine. The last layer may be completed using a number of techniques including those used in the CFOP method. An expert variant of this method (ZZ-a) allows the last layer to be completed in a single step with an average of just over 12 moves and knowledge of at least 177 algorithms.

Petrus method

The Petrus method, named after its inventor Lars Petrus, is considered to be more intuitive than the structured CFOP method. The first step of the Petrus method is to solve a 2×2×2 block of the cube. This block is then extended to a solved 2×2×3 block. All edges are then oriented and the first and second layers are completed. Next, the top corners are put in the right place and the layer is oriented correctly (all stickers facing up) and finally the last edges are permuted (moved around). Lars Petrus developed this method to address what he felt were inherent inefficiencies in layer-by-layer approaches. This method is often used as the basis for fewest moves competition .

Corners-first methods

Corners-first methods involve solving the corners then finishing the edges with slice turns. Corners-first solutions were common in the 1980s, with one of the most popular methods that of 1982 world champion Minh Thai. Currently corners-first solutions are less common among speedsolvers. Dutch cuber Marc Waterman created a corners-first method in the cube craze, and averaged 16 seconds in the mid-late 1980s.

Competitions

Anssi Vanhala solving a 3×3×3 Rubik's Cube with his feet in 36.72 seconds, at the 2009 Estonian Open.

According to the World Cube Association (WCA), competitors (in the same round) must solve cubes that are scrambled using a consistent set of moves (every competitor solves the same scramble). During the first world championship, competitors were not allowed to use their own cubes and were required to use those that were issued by the competition. These cubes were very low quality by speedcubers' standards, but since the revival in the 2000's this no longer applies and competitors can use whichever cubes they choose that comply with WCA regulations. Currently, the official timer used in competitions is the StackMat timer. This device has touch-sensitive pads that are triggered by the user lifting both of their hands to start the time and placing both their hands back on the pads after releasing the puzzle to stop the timer. In addition to the electronic timer, there are human judges with stopwatches who time the 15-second inspection period before each solve, as well as solves which may take longer than 10 minutes. These judges also ensure that the competitors are following competition regulations.

The World Championship in 2008 used a "Best of 3" system for the 3x3x3 cube to determine the winner, where the best solve out of three was taken and used to rank competitors. From 2003 to 2005, competitions began implementing the "Average of 5" system for this same event (five solves are completed each round, with the fastest and slowest times being disregarded and an average being taken from the remaining three). By 2006, this was the primary system for competition and it has remained so. Typically puzzles such as the 2x2, 3x3, 4x4, 5x5, pyraminx, and megaminx use an Average of 5, while cubes such as the 6x6, 7x7, and the blindfolded event use a "Mean of 3" (an average taken from three solves, with none removed).

Official competitions are currently being held in several categories.

Category	Cube Type
SpeedSolving	2×2×2, 3×3×3, 4×4×4, 5×5×5, 6×6×6, 7×7×7
Blindfolded Solving	3×3×3, 4x4x4, 5x5x5
Multiple-Blindfolded Solving	3×3×3
One Handed Solving	3×3×3
Solving with Feet	3×3×3
Solving in Fewest Moves	3×3×3

Speedsolvers solving Megaminxes at the 2011 Estonian Open.

Competitions will often include events for speedsolving these other puzzles, as well:

• Megaminx
• Pyraminx
• Square-1
• Rubik's Clock
• Skewb

World Rubik's Cube Championships

The WCA organizes the World Rubik's Cube Championship as the main international competition once every two years. The latest championship was held in São Paulo, Brazil, from July 17-19, 2015.

Championship	Year	Host	Dates	Nations	Puzzles	Events	Winner	Winning time(s)	Ref
I	1982	Budapest	June 5	19	1	1	Minh Thai	22.95
II	2003	Toronto	August 23–24	15	9	13	Dan Knights	20.00
III	2005	Lake Buena Vista	November 5–6	16	9	15	Jean Pons	15.10
IV	2007	Budapest	October 5–7	28	10	17	Yu Nakajima	12.46
V	2009	Düsseldorf	October 9–11	32	12	19	Breandan Vallance	10.74
VI	2011	Bangkok	October 14–16	35	12	19	Michał Pleskowicz	8.65
VII	2013	Las Vegas	July 26–28	35	10	17	Feliks Zemdegs	8.18
VIII	2015	São Paulo	July 17–19	37	11	18	Feliks Zemdegs	7.56

World records

The following are the official speedcubing world records that are approved by the World Cube Association.

Note: For averages of 5 solves, the best time and the worst time are dropped, and the mean of the remaining 3 solves is taken. When only 3 solves are done, the mean of all 3 is taken as normal.

Event	Type	Result (Min:Sec.100ths)	Person	Competition	Result Details (Min:Sec.100ths)
2×2×2	Single	00:00.58	Rami Sbahi	Canadian Open 2015
	Average	00:01.51	Lucas Etter	Music City 2015	00:01.24 / 00:01.69 / 00:02.21 / 00:01.45 / 00:01.39
3×3×3	Single	00:05.25	Collin Burns	Doylestown Spring 2015
	Average	00:06.54	Feliks Zemdegs	Melbourne Cube Day 2013	00:06.91 / 00:06.41 / 00:06.25 / 00:07.30 / 00:06.31
4×4×4	Single	00:21.97	Sebastian Weyer	Euro 2014
	Average	00:26.03	Sebastian Weyer	German Nationals 2014	00:26.06 / 00:27.08 / 00:26.36 / 00:25.68 / 00:24.86
5×5×5	Single	00:48.42	Feliks Zemdegs	US Nationals 2014
	Average	00:51.93	Feliks Zemdegs	TCG & Friends 2015	00:53.38 / 00:52.81 / 00:48.54 / 00:54.26 / 00:49.61
6×6×6	Single	01:33.55	Kevin Hays	Indiana 2015
	Average	01:45.98	Kevin Hays	World Championship 2015	01:43.04 / 01:51.66 / 01:43.23
7×7×7	Single	02:23.55	Feliks Zemdegs	World Championship 2015
	Average	02:33.73	Feliks Zemdegs	World Championship 2015	2:33.40 / 2:44.25 / 2:23.55
Megaminx	Single	00:37.58	Yu Da-Hyun	Spring Comes 2015
	Average	00:42.89	Yu Da-Hyun	Asian Championship 2014	00:47.53 / 00:43.88 / 00:40.16 / 00:43.15 / 00:41.65
Pyraminx	Single	00:01.36	Oscar Roth Andersen	Danish Special 2013
	Average	00:02.56	Drew Brads	Virginia Open Fall 2014	00:02.46 / 00:02.65 / 00:02.58 / 00:09.19 / 00:01.96
Square-1	Single	00:06.96	Bingliang Li	Guangzhou Wushan Open 2014
	Average	00:10.21	Bingliang Li	Guangzhou Wushan Open 2014	00:09.36 / 00:11.43 / 00:06.96 / 00:09.83 / 00:12.06
Rubik's Clock	Single	00:03.73	Nathaniel Berg	Danish Open 2015
	Average	00:05.94	Evan Liu	Xi'an Cherry Blossom 2015	00:06.34 / 00:05.84 / 00:07.66 / 00:05.63 / 00:04.80
Skewb	Single	00:01.68	Jan Bentlage	World Championship 2015
	Average	00:02.99	Michał Rzewuski	ŚLS Sosnowiec 2015	00:02.39 / 00:03.70 / 00:03.14 / 00:02.87 / 00:02.95
3×3×3: Blindfolded	Single	00:21.17	Marcin Kowalczyk	PLS Szczecin 2014
	Average	00:25.45	Marcin Kowalczyk	Berlin Summer Cube Day 2015	00:25.88 / 00:29.22 / 00:21.24
4×4×4: Blindfolded	Single	02:02.75	Oliver Frost	Irish Championship 2015
5×5×5: Blindfolded	Single	05:18.65	Roman Strakhov	CCC End of Summer 2015
3×3×3: Multiple Blindfolded	Single	41/41	Marcin Kowalczyk	SLS Swierklany 2013	54:14
3×3×3: One-handed	Single	00:06.88	Feliks Zemdegs	Canberra Autumn 2015
	Average	00:10.87	Antoine Cantin	Toronto Spring 2015	00:10.56 / 00:14.19 / 00:10.58 / 00:10.07 / 00:11.47
3×3×3: With feet	Single	00:20.57	Jakub Kipa	Radomsko Cube Theory 2015
	Average	00:28.41	Gabriel Pereira Campanha	SESC Santos 2015	00:29.72 / 00:26.97 / 00:28.53
3×3×3: Fewest moves	Single	20	Tomoaki Okayama	Czech Open 2012
			Rami Sbahi	Michigan 2015
	Average	25.00	Sébastien Auroux	Velbert Easter Open 2014	27 / 27 / 21
			Vincent Sheu	US Nationals 2014	22 / 23 / 30
			Jan Bentlage	CBNBC 2015	28 / 22 / 25
			Sébastien Auroux	N8W8 Summer 2015	26 / 27 / 22

A scatter plot of Rubik's Cube world records(single and average) against time. This depicts the improvement made over the years, as well as highlight records that stayed unbroken for an unusual amount of time.

Lubrication

Some members of the cubing community lubricate their cubes to allow them to be manipulated faster, easier, and more reliably than a non-lubricated cube. The WCA allows lubrication for official competitions.<

Some of the popular lubricants among speedcubers are:

• Lubix Cube Lubricant
• CRC Heavy Duty Silicone Spray
• D-39 Silicone Spray
• Cyclo Silicone Spray
• Maru Lubricant
• Traxxas 50K Differential Oil
• Cubesmith Lubricant
• Cubicle Silicone Lube/Lubicle

Checking a lubricant's MSDS is often helpful in identifying cube-damaging ingredients.

Building and Modification

A smaller portion of the cubing community, known as modders, dedicate themselves to creating ideas for new cubes, modifying existing cubes, and designing and producing the new puzzles themselves.

Building

The building of puzzles usually consists of start from scratch, from materials such as plastic sheets, or designing them in a 3D CAD software, such as programs like SolidWorks.

Modding

The modding community, larger than the aforementioned, takes existing puzzles and executes a process to have some desired effect. Most mods consist of simply sanding pieces down, to reduce friction, while other, more complex ones, involve cutting, shaping, and adding plastic to the puzzle to change shape and its overall mechanism and difficulty. These kinds of mods can range from simple ones such as the Cutter Cube, in which the center layer is misaligned, and the pieces are shaved down to make it seem as though it isn't, to more complex ones such as the Ghost Cube. It can be of any type.

Terminology

Below are some definitions of words generally used by the speedcubing community. For a more complete list of speedcubing terminology, see the cubefreak.net glossary.

Algorithm

A predefined sequence of moves used to effect a specific change on the cube. Often referred to as alg or (less commonly) an algo.

BLD

Blindfolded solving, i.e. memorize, don blindfold, then solve.

Center piece

One of the centers of the faces of the cube. The centers never move relative to each other on an NxNxN cube, where N is odd. On NxNxN cubes where N>3, every piece with only one sticker is referred to as a 'center piece', including those pieces that can move relative to each other.

CLL

Corners of the Last Layer. This is the first of two steps of one of the methods of solving the last layer of the cube. In the process, edges may be unoriented. This is used in Corners First methods for the last layer, in which the first all corners are solved, followed by the edges (see ELL). CLL is also commonly used to solve the last layer of a 2x2x2 cube in one step.

Commutator

A commutator is a sequence of the form X.Y.X'.Y' (also represented as [X:Y] or [X,Y]) which affects only specific portions of the cube, leaving the rest untouched. This is used in Blindfolded solving and Fewest Moves Competition.

Corner piece

One of the 8 pieces with exactly three stickers, called a "corner" piece because a corner is exposed.

Cuber

Someone who solves any size of Rubik's Cube.

Cubie

One of the mechanically independent pieces that make up a puzzle. The cubies do not include fixed center pieces, the central axis to which they are attached, or any other internal pieces (Such as the internal edges of a 4x4 or 2x2).

Cycle

To rotate pieces' positions on the cube. e.g. a 3-cycle would make cubie set A-B-C become C-A-B.

DNF

Initialism for Did Not Finish, used in competitions and self-timing. e.g. when a piece pop occurs and the competitor decides not to continue solving the puzzle, or when the solver stops the timer with the cube still unsolved.

DNS

Did Not Start, used in competition when the competitor does not begin a solve, either by opting to skip it (common in Blindfold Cubing), by not showing up when he or she is called, or not qualifying for the remaining (usually three) solves of a certain round.

Edge piece

One of the 12 pieces with exactly two stickers, called an "edge" piece because only one edge is exposed.

ELL

Edges of the Last Layer. The second of two steps of one of the methods of solving the last layer of the cube, solving the edge pieces without disturbing the corner pieces (see CLL).

F2B

First two blocks. This is used in the Roux method.

F2L

First two layers. This is used in the CFOP (Fridrich), Petrus, and ZZ methods.

GJ

Short for Good Job, usually used to congratulate a cuber on a fast solve

Layer

One section of a cube consisting of a number of cubies that turn as a unit. (e.g. A standard Rubik's Cube has 3 layers.)

LL

Last Layer. Usually refers to the top layer of the cube, but for the Roux method can refer to the middle layer between the left and right faces.

Method

A combination of steps that can be used to solve a cube.

Move

A turn of one of the sides of a puzzle, or knobs in the case of the clock.

N-look, also known as X-Look

Refers to the number of algorithms needed to complete a step in a particular solving method, often the last layer, e.g. '4-look LL'.

OH

Short for One-Handed, it is the event or practice of solving a cube with one hand, left or right.

OLL

Orientation of the Last Layer, usually used in reference to the respective step of the CFOP and ZZ methods.

Orient

To change the orientation of a piece.

PB

Personal Best - personal record time to solve a puzzle. This can either be a single attempt or a trimmed average, depending on context.

Permute

To relocate certain pieces in a way to achieve a desired result.

Phasing

Used in various methods, it is a technique that allows the shrinking of algorithm sets by using alternative moves. e.g. Using phasing with ZZ-a will turn it into a reduced subset known as ZZ-b.

PLL

Permutation of the Last Layer. Usually used in reference to the respective step of the CFOP and ZZ methods, in which case it would follow the OLL step.

Pop

When, during a solve, one or more cubies come out of contact with the puzzle, usually causing the puzzle to be unstable, in which, upon turning, more pieces may become loose.

Prime

A counter-clockwise move popularly denoted with a ', e.g. 'R Prime', denoted as R', R-, $R^{-1}$, or Ri. Also (less commonly) known as "inverse" or "inverted".

Slice

The four center pieces and four edge pieces between two opposite layers of the cube.

Two-Second Penalty, also known as +2

A penalty of 2 seconds which is added to a solving time in official competitions when the cube is placed back on the timing pad with one or more faces misaligned 45 degrees or more. It can also be given in other cases, such as when the competitor starts the timer too slow or does not correctly stop the timer after finishing the solve.

UWR

Unofficial World Record.

WCA

World Cube Association, the international governing body for official cube competitions.

Winter Variation, also known as WV

A subset of algorithms for F2L that allows the user to force all upper-face corners to be oriented correctly, or an OLL-Skip. It is used when the last F2L pair (One corner and its corresponding edge correctly positioned relative to each other) to be inserted is in the top layer, with the 3 top-layer edges oriented correctly. There are a total of 27 cases. WV has an average lower move-count than the standard OLL.

WR

World Record. Can also be "World Rank" when referring to the rank of a person's record in a database.

X-Cross

Completing an F2L pair during the cross setup, used almost exclusively in the CFOP method.

ZBLL

Considered one of the holy grails of speedcubing. It is a set of 177 algorithms (Not including mirrors and inverses) with 494 cases to recognize in order to solve the last layer in one look, also known as 1LLL, with an average move count of ~12.08. Can be used in any layer-by-layer method that ends in N-Look LL, but will only really be efficient in ZZ, as the method keeps edges oriented, whereas methods such as CFOP do not keep the edges oriented, becoming a sometimes 2LLL solve.

YTUWR

Youtube Unnofficial Word Record, the fastest of something that is posted on YouTube.

See also

• Rubik's Cube
• World Cube Association
• Feliks Zemdegs
• Mats Valk
• Eric Limeback
• Anthony Michael Brooks

External links

• Speedsolving.com
• Speedsolving.com Wiki
• Fridrich Method
• Roux Method
• ZZ Method